[ringoism]

Finally got a stock piston beside an Apache180 piece and realized my idea of simply overboring or sleeving the stock Hero block to accept it (strokes are identical) was not going to work, namely because the Apache‘s piston pin is 1mm larger in diameter. Piston is considerably heavier, too, being about 5mm larger diameter, so vibes would likely show up and corrupt the stock engine‘s silky perfection.

But here‘s a few other interesting new possibilities re: Impulse performance enhancements:


1. http://www.motorbeam.com/2012/02/bik...honda-engines/

The possibility of a transformation into a healthy 180cc machine, with perhaps a half-hour of labor to swap the top-end (cyl. block/piston). Apparently utilizes a “semi-forged“ piston, and if that means it‘s near light as stock, that would b great. Re: price, only says “four digit“ and if that means 9,999 it might be pushing things value-wise. Other downside is that it must be a custom piston, in which case replacements / overbores will be expensive, if possible at all.

2. New Unicorn 160 has gained its extra 14cc‘s (being 163.7cc) via a 63mm stroker crank (vs57.8 stock) which might be a direct bolt-in, as the engine is based on the 150. A lot more work fitting it, but probably not more than Rs3-4,000 from Honda for the part itself, and has the advantage of enhancing bottom-end torque (which the Impulse really needs more of), without likely affecting FE noticeably.

3. Everyone‘s been worried about the legality of the 223cc Karisma transplant, but some personal conversations with both an RTO in H.P. and a MVI (Motor Vehicle Inspector) here in Mizoram, all indicate that it should not be difficult to get permission for such a change; Karizmas are becoming common enough in scrapyards as to be cheap, it‘ a tough motor that‘ supposed to be an easy swap‘ it‘ sized right for the bike, and if it‘s all legalbesides, then it might be a feasible option on all fronts.

Personally I might be leaning towards the stroker crank + a modest (and cheap) 1mm overbore which would give just under 170cc and bump the compression up to about the right range too. This with free-flow silencer / air filter / correct tuning would have to get you around 16bhp and more torque than anything in its class, too, with still acceptable FE, likely all for within Rs5-6,000 in parts. Sounds about right.... if I can bear to dig into a perfectly good, 6,000km engine to do it...

-Eric

[utpal]

Hi Eric,
First of all, thank you for a very informative thread.
Even though I am not technically sound I still loved reading your experience and your experiments with the Impulse.
I have always rode Bullets, but during my ride through Spiti last year I found myself wishing many times for a lighter, more maneuverable bike.
Now that you have owned and rode and tinkered with the bike for almost a year, would you still recommend a highly non-technical person to buy the Impulse?
If I were to pick up a used Impulse, what modifications would you suggest be done to the stock bike before riding to high altitude?
Since I am mechanically illiterate, do you think I should go for the Impulse? Or would you recommend some other bike?
I apologize if my questions are inappropriate to the thread, or if I am going off topic.

regards,
Utpal

[nitro.1000bhp]

Originally Posted by ringoism

Finally got a stock piston beside an Apache180 piece and realized my idea of simply overboring or sleeving the stock Hero block to accept it (strokes are identical) was not going to work, namely because the ................................................ too, with still acceptable FE, likely all for within Rs5-6,000 in parts. Sounds about right.... if I can bear to dig into a perfectly good, 6,000km engine to do it...

-Eric

Hi Eric,

During my trip to Leh in 2013, my friend on his stock impulse had a major problem selecting the right gear during steep high altitude climbs. You must know there is a significant gap in the ratios between 1st and 2nd. So he was having to either rev the nuts-off 1st gear or shift to 2nd and pray to God the torque catches up. More Torque lower down the rev range would definitely help but how would you go about increasing torque without stroking the cylinder? How much ever power you can increase that gearbox will let you down. Unless you can get the engine to spin-up quickly from a lower rev range, chances are you'd never see any use for that power increase .

My suggestion is : Try a gear box swap (or gear ratio swap) from the Unicorn or Extreme, Sprocket accordingly, try lightening the flywheel so the revs can rise faster and then maybe go for that power upgrade.

But I applaud your relentless efforts to sort the stock impulse out than chicken out like me and swap the entire motor....Kudos Man.

Regards,
Girish.

[ringoism]

Originally Posted by utpal

Now that you have owned and rode and tinkered with the bike for almost a year, would you still recommend a highly non-technical person to buy the Impulse?
If I were to pick up a used Impulse, what modifications would you suggest be done to the stock bike before riding to high altitude?
Since I am mechanically illiterate, do you think I should go for the Impulse? Or would you recommend some other bike?

Thanks for your interest. At this point hard to recommend the Impulse for non-tech types, unless you've also got someone around who knows how to get into some of my aforementioned mods and even beyond those on your behalf... I still don't have mine where I want it, even after a lot of time fooling around. Honestly Bullets are not really an ideal machine for Ladakh, etc, either, but they're pretty serviceable, solid, and kind of keep chugging along steadily out there. RE 500's do particularly well, and hardly seem fazed by the altitude. True, they're heavy, don't have much suspension, and kind of make you feel like you're riding an engine rather than a bike, but... well, what to do? I keep holding out hope that one of the Indian manufacturers is going to finally come out with the ideal medium-displacement adventure touring bike at reasonable cost... but maybe I'm hoping too much. Anyway, most basic thing for altitude is jetting, and the most basic jetting change (main jet) is pretty simple. That alone won't make it great, but it will be more tolerable than stock.

Originally Posted by nitro.1000bhp

...You must know there is a significant gap in the ratios between 1st and 2nd. ...but how would you go about increasing torque without stroking the cylinder?...Unless you can get the engine to spin-up quickly from a lower rev range, chances are you'd never see any use for that power increase.

My suggestion is : Try a gear box swap (or gear ratio swap) from the Unicorn or Extreme, Sprocket accordingly

Thanks...ratios are certainly part of the difficulty and I appreciate your suggestion. I suspect the Impulse was deliberately geared a little low in 1st in order to allow what is really a kind of overweight, underpowered "dual-sport" bike the ability to - one way or the other - manage to get up particularly steep gradients. I'm pretty sure, having ridden around Aizawl a bit on an FZ (which has more power but a higher 1st), that the lower 1st would be a real boon in certain, specific situations. Unfortunately, it's a real pain in the neck in about 99% of other normal situations! Oddly, I compared owner's manuals with the Extreme, and it claims ratios are identical. Not sure about the Unicorn, but will check with a friend who has one this week.

The way I see it, while stroking would be better for torque (which is how the new Unicorn 160 picks up its extra, and if swap-able might be perfect), even with boring I do increase my bottom-end a bit, which helps me utilize second-gear better, so that I don't get bogged down and forced to shift back into first repeatedly. One guy I met out there last year had switched from a 17 to a 15-tooth front sprocket - obviously this would grant a lot more torque in second gear, but it would also make 1st gear way too short under most conditions, and moreover my top end (More Plains, some parts of Leh-Kargil, etc) and FE locally would also suffer.

More power/torque output kind of helps make gearing less critical - which is why a RE500 will go over the same grades/altitudes that are difficult for the Impulse, in probably any random one of at least three gears without trouble.

-Eric

And P.S., yes, at points out there, I was indeed "praying to God" that it would make it up that grade... just terrible.

[nitro.1000bhp]

Originally Posted by ringoism

Thanks...ratios are certainly part of the difficulty and I appreciate your suggestion. I suspect the Impulse was deliberately geared a little low in 1st in order to allow what is really a kind of overweight, underpowered .............................And P.S., yes, at points out there, I was indeed "praying to God" that it would make it up that grade... just terrible.

Found this on the net. Its a comparo of ratios bet'n the NXR150 and impulse.
See the massive difference in the 2nd gears? Surely that can't be right. Just What the *** were they (Hero) thinking? I guess they just put in which ever gears they had lying around the factory and gobbled out a gear-box. Shame.

[ringoism]

Originally Posted by nitro.1000bhp

See the massive difference in the 2nd gears? I guess they just put in which ever gears they had lying around the factory

Guess that's right.

I'd already compared the Extreme's gearing and found it identical, and now finally got around to checking the Unicorn's - which is also identical, apart from its utilizing a slightly higher 2.8* final drive ratio.

Question then becomes, why does the big 1-2 gap FEEL so objectionable in the Impulse and not so much (IMO) in these others? I've ridden these two a bit - especially the Uni (incl. under extreme conditions to Spiti's 14,000ft. Chandra-Tal and back), which even at very low revs both pulls and remains silky smooth, whereas the Impulse gets very flat and rough - even clattery. The Impulse is advertised as being tuned for "high torque" but in all honesty, despite what the published numbers claim, I feel it has more mid/top end (kind of like the Extreme) compared with the Uni, and considerably less low-end.

Ironically, the Impulse would probably outrun the Honda handily on flat, plain roads - but despite its would-be dual-sport intentions, it struggles at low rpm's and altitudes where the Honda manages better. My current theory is that it's mainly tied up in the camshaft profiles, though there might be other causes as well.

**********

As an aside, soon after the 6,000km service a month ago (and at about a year of age), my Impulse engine started consistently emitting sharp, rattley (crank-like?) sounds at two points in the rpm scale - 3,000 and again at 4,500-5,000. Hoped it might be detonation, but switched to a colder plug and it sounded the same, so guess not.

I'd noticed this noise in a friend's (approx 10,000km's) Impulse that I test-rode some months before buying mine, and had been surprised, given the H/HH 150's reputation for quiet smoothness / long life. Highly annoying as I do spend a lot of time at those speeds.

Local mechanic friend (one of the few good ones out here) says it's pretty much normal with all these newer bikes, and indeed I've heard something similar on a pretty new P180 and a couple of fresh CBZ (Extreme)'s I rode. But the Uni I sometimes ride has more km's, has been ridden/abused (as an institutional unit) by all sorts of random people, and is still quiet at all speeds.

Hero, post exodus of what must have been their Honda overlords, just seem to have screwed up this bike royally. Saw another year-old one a few days ago at the agency (a Russian tourist had just bought it second-hand from Karol-Bagh in Delhi) that had a rusting/pitted frame and chrome bits (my 1992 KB100 has been parked outside and rarely washed for at least the last ten years, and has less coatings failure than what I saw there; my own Impulse had light frame rust right from the showroom, which they touched up with a spray can before delivery).

The Impulse is unique and still has got potential, but (as this poor Russian chap is about to discover) it's definitely not a turn-key Himalayan tourer, and I'm near to concluding that it's sadly not really compelling enough in any other way to love it despite its comparatively low quality and quirks.

Having said that, I'm not really sure what new bike I could have bought new a year ago that would've served my purposes any better, BUT...

Bajaj's (now discontinued) Boxer 150 - itself not a high-grade bike, but with the same suspension mods I'd applied to my KB's, it would've likely been just as capable (or more, being lighter/nimbler) than the Impulse at much less cost. But I didn't even realize it existed when I was considering the Hero.

Honda's Unicorn, apart from the lower ground clearance, would've been as good a performer (or perhaps better, with the new 160) on all but the absolute worst tracks, and more comfortable in terms of suspension, seat width, saddle height, and maybe grip position (I had no soreness / pain whatsoever after nine hours on the absolute worst of roads).



But in retrospect, I kind of wish I'd just sought out a second-hand BMW K650 Funduro (there used to be a locally-registered one up here); So long as I didn't mind ordering parts from abroad (couldn't be worse than the two months Hero's been failing to get me a new turn indicator), THAT for me would seem the perfect "turn-key" solution.



-Eric

[ringoism]

A RARE TRIO

Couldn't get a much more eclectic or unusual combination of machinery than this: A thundering RE Machismo (AVL) 500, a beautifully maintained early-model Hyosung Comet 250 V-twin (mildly modded, and oh, the sweet sound!), and the (comparatively lowly - and excessively docile!) Impulse.

Destination was a hill at ridge-end overlooking Kullu/Bhuntar, where the "Bijli Mahadev" temple (with its predictable lightning rod) is located. The views from the point just beyond the temple are the real treat - just breathtaking, a full panorama extending down Kullu Valley towards Pandoh, East up the Parvati Valley, West into Lug Valley, and North to the high snowy ridges that tower over Lahaul/Spiti.

Normal route is by vehicle/walk from Kullu, but I've always opted for the considerably longer, more challenging, and more beautiful forest road from Naggar. Not really open to four-wheelers (probably possible only by Gypsy), for two-wheeler and cycling enthusiasts it is the perfect place to enjoy a bit of the pristine natural environment more or less as originally designed, and as such the route has never failed to provide a worshipful experience for me:



I'd done the trip a few times earlier on the KB100/125's, but it was a first on the Impulse and I was interested to see how it compared to those.

Versus the other two of this odd trio, it was of course the most suitable for such a broken track, and though it enjoys less than half the power output of either, had no issues keeping up at any point; especially since anything like smooth pavement was scarce. We did about 100km in total.



The other two riders were probably more experienced than I, one having owned/ridden some racing dirt bikes like Suzuki's beastly RM500 in Norway, the other a KTM Adventure in the U.S., on which he'd traversed the rugged Rocky Mountains solo by roads less traveled (i.e., dirt). On the downside, they'd both had neck injuries in the past, not a great match for bikes with a lot less suspension than the humble Hero.












The Impulse had honestly been seeming pretty, well, crappy to me lately, but at the end of the day, I'd really started to like it again. This is the sort of stuff it was really intended for, and while it wasn't as nimble, tossable, torquey, or even plush as my old KB125, it managed admirably well. This would be, at some points anyway, one of the rougher and more demanding roads I've ridden and we were pushing quite hard, yet at the end of the day, I felt very little discomfort or fatigue.

To sum up: A couple of good companions with good riding skills, a trio of rather rare and appealing specialty bikes, and hour after hour of a diverse natural environment of extreme beauty: As day trips go, it doesn't get much better than this!

-Eric

[Cj3bDog]

Hi Eric,

I have been an amid reader of your posts, quotes and threads. Have already read this and your "Marshal" thread more than thrice. Love your realistic, practical and subtle approach towards your vehicles.

Wanted your suggestion on buying Impulse. I already have a Royal Enfield Thunderbird, which is doing all that I need and want to. It is an amazing machine and I do not intend to sell it off any time in the near future. Have no modifications done to it and love it the way it was built.

I want to add another motorcycle to my garage and have been thinking of "Impulse". From a purist perspective, would you recommend Impulse for a daily drive of 20-30 kms in plains. Would you suggest any significant changes done to the original machine, since I read about all the Carbs and jets you have been playing around with.

[ringoism]

Originally Posted by Cj3bDog

Wanted your suggestion on buying Impulse. I want to add another motorcycle to my garage and have been thinking of "Impulse". From a purist perspective, would you recommend Impulse for a daily drive of 20-30 kms in plains. Would you suggest any significant changes done to the original machine, since I read about all the Carbs and jets you have been playing around with.

Sorry to be just seeing this so late...

I myself like the Thunderbird, by the way - IMO a very relaxed and undramatic sort of machine that just does its job well.

By "purist perspective" I'm guessing you mean purely as a rider: In that sense, I like the Impulse's fairly confident road handling, the smooth engine, and the commanding (high) seating position which can give you a good view well ahead (over the roof) of the car you're actually following. Power comes on pretty strong (for a 150) starting around 5,000rpm. The suspension is pretty capable for rough roads, though it's far from being plush like a true dual-sport (DR/XL/etc) with 10" suspension travel would be. Also a pretty primitive suspension in the sense there's no pro-link out back or progressive damping up front, etc. Just basic, does the job okay. Seat's pretty decent, too. 20-30km/day in the plains is nothing for this bike.

I do NOT, however, think it is a very well sorted bike and it has a few "bugs" and questionable quality control compared to HH's earlier reputation; I get the feeling it was rushed to market in a time of corporate transition.

Parts supply is often an issue, as few ASC's stock much of anything for them. Does share many parts with other bikes, though.

If you're running nearer sea-level than we are up here, I don't think there will be issues with jetting. Their performance seems to improve inverse to altitude, and to me the bike has felt really strong when I was at or below 1,000m.

With a little fiddling it can be a great all-rounder and more practical than many of the other sporting-type 150cc offerings. But it's not exactly a no-strings-attached sort of relationship. It's going to demand a little of you.

One kind of interesting thing is that, despite its being perpetually dirty and looking sort of neglected, my bike still draws a lot of attention, getting thumbs-up from admirers looking it over or watching me ride alongside their car, and I even get some questions that surprise me - like whether it's an Indian bike, or imported!

Not any kind of superior dual-sport, but an interesting, unique, and (apart from the bugs and spares issues) a pretty practical machine. I'm guessing you can pick up nice second-hand ones in Delhi pretty cheap these days.

Hope that helps, and glad you've enjoyed some of my threads.

-Eric

[ringoism]

Latest news:

1. Carb slide (piston) had been repeatedly (and increasingly) sticking closed in rainy/humid/cold conditions - a real pain when I was out in Spiti in July (had to keep kicking the carb with my right foot while riding, to loosen it). According to some owners on the xBhp ownership thread, this is a very common issue for some reason. Now finally resolved (I think):

Took me a long while before I could think about it in raw mechanical terms, re: the actual physical cause of its binding in the bore (it was absolutely clean and damage-free). Finally realized that what was probably happening is that under high vacuum (throttle closed/decelerating), the piston was getting sucked towards the intake manifold and becoming slightly cocked in the bore, thus getting stuck at the bottom of the travel.

Question was why on this bike and so rarely on others with similar CV carbs. They even said that fitting the Unicorn's slide takes care of it. Huh??? Maybe a different, more slippery anodized coating? Many personal attempts (some jugaad) at rectification - polishing, etc. All ineffective.

Finally got a wild idea and trimmed off the radial-locating tab on the rubber diaphragm, which determines its rotational orientation in the carb body; and then turned it, with the piston, 180degrees (backwards) in the bore, and reassembled! Problem seems solved now.

Why? Well, for whatever reason, Keihin had two little flat spots machined into the slide on the engine side, right where the piston would otherwise be contacting the leading edges of the bore. Don't know if they were trying to reduce friction here or what, but if so, it was kind of counter-productive, being at the expense of not having support for the piston in the lower portion of its travel, thus enabling it to get out of alignment in the bore and cause even greater binding/friction elsewhere. So turning it around put the full-radius (formerly back) part of the piston into a place where it could be used for support in the lower part of the bore; thus it doesn't get cocked in there, and no longer sticks when under high vacuum conditions.

Strange, eh (and why should I be having to figure this out, instead of Hero/Keihin)?

2. Finally got the carb tuning right for 11,000+ft altitudes while out in Spiti: #121 high-speed jet, main needle dropped by shaving flange to 0.6mm. Really ran fine like this, with plenty of power and no misfiring. A smaller idle (pilot) jet than the stock #35 would be helpful (if I want the bike to idle out there) but otherwise seems "right".

3. Both tyres (CEAT GRIPP XL) are exhibiting serious cracking in the sidewalls - enough to cause a puncture in the front one. Quite disappointing for a bike with a mid-2013 production date (the Dunlops on my KB's are as old as ten years, with none of this in evidence):




These were kind of more road-biased tyres anyway (despite not being very quiet), and never really thought them ideal for my sort of riding. CEAT has apparently stopped making these, and the SIRAC is also no longer available, and if something else equally/more aggressive is out there in this size, I've not found it; 3.25-19's (Dunlop Unilug, etc) as used on Bullets are a little too wide and way too heavy; so am planning to upgrade to a 2.75x21" setup of semi-knobby style. Have the rim already, tyre hopefully will make it through from abroad (Shinko 244, highly rated Korean tyre, and dirt cheap at $35).




Only think I lack now is the right spokes.
Anyone know somebody in Delhi (Karol Bagh?) who does custom-length spokes? Need them to adapt the 21-inch alloy rim to the stock Hero front hub. They'd need to be around 9-1/4" (235mm) long.


Thanks,
Eric

[ringoism]

If anyone else out there has been experiencing a sudden, nasty clatter in the engine at specific rpm's and under load (as mine and at least one other Impulse I know of were), you should know that this CAN be repaired.

Did a lot of research online and came up with nothing; the mechanic at the nearest ASC couldn't even discern what noise I was referring to, and initially, the parent showroom at which I'd purchased it said they'd have to have a Hero engineer come and inspect it before any warranty work could be done; But finally the lead mechanic at the Kullu showroom – who's been at his work for many, many years and earlier worked on vintage Triumphs and Nortons in a specialty Karol Bagh shop, heard the offending sound a couple months back and told me immediately that it was the crankshaft, that it was related to a manufacturing defect, and that if repaired, it would not soon recur. The rattling at 3,000rpm and again at 4,500-5,000 (which had begun soon after the 6,000km service) was extremely annoying in light of the fact that I naturally would spend a lot of time at those engine speeds; so although I wasn't crazy about the thought of splitting the cases on a nearly new engine, I thought that getting it done was the right way to proceed.
The mechanic had been back in his native place for some weeks in the winter, and then I was busy myself, so didn't finally get down there till a couple days ago.

It was an all-day job, but that was a lot better than the estimated two days, and at the end of it I've got a nice, quiet bike again. Being under warranty, there was nothing to be paid but a liter of oil and half the labor charges (Rs800), which seemed reasonable for sixteen man-hours (mechanic and helper) of work without even a lunch break.

Disassembly begins:





An awful lot of parts in this thing vs. the old KB's I've had apart multiple times... and I was glad I hadn't attempted it on my own:




Reassembly with the new crankshaft; I was an absolute stickler when it came to cleanliness, ordering three extra litres of petrol for washing / final dip before assembly, and bringing my own clean cotton cloths to continually wipe hands / parts with (it really does make a difference, as leftover dirt is one of the main reasons that opened engines often don't last as long as the originals):








Surprisingly, a broken spring on the balance shaft drive gear, and no new ones in stock in the parts room:




Mechanic resorted to a trip to an electrical motor rebuilder's shop, where he found something close with which to perform a little jugaad




Another surprise, another manufacturing mistake - a rounded-off nut on the clutch housing - on a previously unopened engine...




Mechanic was capable, but managed to prematurely tighten one of the clutch-bearing retainer bolts, snapping the casting (he found a used one to replace it with)




Discovered on disassembly that the camshaft timing would appear to be fairly easily adjustable, as the gear flange is simply press-fit onto the camshaft, and can actually be removed / probably re-installed in any orientation desired. A little more cam advance would (in theory) move the torque curve a little lower, which would be helpful for my uses. If I'm seeing it right, it actually looks to be a little retarded (shaft a little clockwise from the flange) - possibly another case of manufacturing tolerance - which would add to the issue of a torque peak that seems to be at too high an rpm.



The piston itself seemed to be running a little loose (.004" clearance, where as a rule of thumb I assume a thousandth for every inch of bore - in this case around 2.25", so a .0025" clearance might be more appropriate), but rings seem to be sealing fine and in my use (frequent high, continuous uphill loads in cool air), a little loose is preferable to too tight anyway. It's not as silent sounding as the Unicorns I've ridden, but I can live with some very light piston-slap at certain loads/speeds. Being that some of the original finish is still visible on the piston skirts, and some of the original honing in the cylinder, I'm going to assume this is one more area where Hero's manufacturing tolerances were just a little loose to begin with. Incidentally, since it was debated somewhere in the forums here on tbhp (or xbhp?), I compared this cylinder to that of a Hunk, and could find absolutely no variation in design. Only thing is that the Hunk has a black colored block, and the Impulse's silver; and some manufacturing markings, of course (interestingly, the Hunk's has a "KSP" (likely their supplier) marking rather than the Hero insignia.




Though the Impulse piston has the same "KSP"...




For anyone changing a timing chain, cam gear marks should be parallel with the cylinder head top when the two marks on the flywheel are aligned with that on the cover:




Getting back to the crank and its particular issue:

The rod was not discernably loose in terms of the usual side-to-side rocking or up/down play, BUT upon checking it out with a set of feeler-gauges, I found it to have double the thrust clearance (.012") vs. the new one (.006"), so I suppose that was the culprit – I'd read earlier that excessive clearances here (in any bike engine) can set up potentially destructive vibes. As this is not really a wear-intensive area, I'm assuming the crank had been put together wrong at the point of manufacture.

The piston pin and small end of the rod also (oddly) seemed scored a bit, though any wear was unmeasurable with the limitations of my vernier caliper.


Anyway, with RE's Himalayan launch having finally come and the bike turning out an astounding 50kg's heavier than my Impulse, I'm inclined to stick with the latter for the foreseeable future; Though the bike is imperfect, it is solid, and responsive to certain improvements thus far. Had considered the 225 Karizma swap, but having ridden a friend's new “ZMA” the other day, not sure it's really quite worth the effort / expense. The 225 surprisingly lacks a balance shaft, so the vibes are noticeably more; it still doesn't really have a lot of low-end grunt (though at high rpms the power increase is very noticeable despite the bike's higher weight), and the FE would suffer considerably vs. the 150, in which I feel there's still some more tweaking possible:

***Aforementioned cam timing optimization.

*** Free up the exhaust a bit more (now that I have a welder, can do a custom-made straight-thru silencer with stainless-mesh packing to keep noise in check).

*** 16T sprocket already on hand (vs. 17 orig) for a little help in case I want to attempt something a bit out of the Impulse's league in terms of power/weight ratio (think Sach Pass), or for simple touring in Kinnaur/Spiti where speeds are lower and river crossings (really more like river runs) are many, and effectively closer gearing would be helpful.

***Have some very nice front fork pump cartridges from a rather more sophisticated progressive damping setup found on a classic Jap enduro bike. Can't mount as-is in the stock fork legs, but might buy an extra set of the same and modify by lathe to allow their installation.

***That 21” front wheel is getting closer to installation...

***(maybe, later) a big-bore kit... though the earlier info that the rod's top end was a bit bigger than the other 150 Hero/Honda's was false. It takes a smallish 14mm piston pin, where old-model CBZ's/zma's, FZ's, Apache 180's and Pulsar 150's are all using 15mm pins. So I'm either going to need a custom piston or find some other bike that's got a piston that can work... which may not be that likely... (forget it).


As it is, the bike's pretty well in order, and looking forward to some riding as soon as all this rain / sleet stops and we get solidly into Spring...

A little disappointed (though not entirely surprised) with what seems evidence of a lot of carelessness / sloppiness in the original manufacture (poor welds on the chassis were the most visible example at time of purchase, but what I'm finding in the engine's internals is more concerning); But still, the bike's basic design is sound, and hoping it'll serve me for a long while.

[ringoism]

Meanwhile...

The old KB125RTZ referred to in the beginning of this thread is the subject of a new effort...and a little transformation...

After a year and a half of very little use and very much neglect, it still willingly started right up a couple weeks back... and is running just great.

The line of thinking here:

The local roads we typically commute on have been getting progressively better (finally truly deserving the "NH" designation), and I'd long thought that the KB had never been at its best on long tours to Nepal, etc, but rather in short, high-spirited little local blasts down to and around town...




So the former "off-road special", for a start, has been slammed back down nearer the tarmac, geared down low with the original front drive sprocket and a bit larger rear one, had a thin-padded, two-level seat fitted, along with a low, clubman-type handlebar.

And oh, boy, this really is just SO much fun to ride, far more responsive and powerful in the midrange than the Impulse, a totally different feel in every way actually - and in summary, a serious, continuous smile-generator.

Oddly enough, it was my wife who provided the inspiration for what is slated to become a cool little cafe-racer, as she is wanting to learn to ride and the Impulse's seat was far to high for her to manage; With our elder son just starting his studies, she about to begin a little work at a school in town, and horrible tourist-season jams about to begin, a two-wheeler was clearly in order; and while I know she had in mind more of a benign, harmless, scooty-like device, it didn't seem reasonable to spend Rs60,000 for a new one when I had this, eh, "perfectly good" classic feather-weight bike sitting unused (am I stretching it here???).

Well, I'm going to try my best to ultimately convince her that the KB will do the job just as admirably as any "scooty". To begin with, the tank actually better lends itself to child seating than either the Impulse or a scooter - and might I add that its lithe form and "classic good looks" would seem a great match, as well...

As for the onward plans: Well, it will be shiny (black? red?)... it will in the next day or two get a disc brake and upgraded rims... It will (finally) get some turn indicators and tail/brake lights and nicer RVM's... and maybe a little custom-fabbed tail fairing. What's for sure is that it will be kept very, very light (under 100kg). But lest I hijack my own thread, might leave all that for another time and place, as the thing progresses (stay tuned).

-Eric

[ATUL SINGH]

Originally Posted by ringoism

[b]

Well, I'm going to try my best to ultimately convince her that the KB will do the job just as admirably as any "scooty". To begin with, the tank actually better lends itself to child seating than either the Impulse or a scooter - and might I add that its lithe form and "classic good looks" would seem a great match, as well...



-Eric

I agree i agree i agree

[ringoism]

Little update:

The Impulse has become, in the wake of its crank replacement, an absolute joy to ride. After a long time - almost a year - I can again ride at the rpm / gear that feels "right" instead of the one selected to avoid the clattering in the innards.

Please, please - if anyone else out there has the same mysterious rpm/load-related rapping in the engine, get your ASC to do the work - and to pay for it if under warranty. There is definitely an issue of manufacturing defect here with this model's crankshaft.

Well, this is not a powerful bike, but it's got some pull, and is a very smooth and predictable performer that (with my current jetting) is also very economical to run. Many have suggested the Karizma transplant, but I would add some weight, give up some smoothness, and still not have a lot of low-end grunt. Might mod this little 150 a bit as time goes on, but it's generally capable enough for most of what I do. When I'm feeling the need for speed thrills, I've another option:

For the KB-RTZ's ongoing transformations, please refer to its own thread:

http://www.team-bhp.com/forum/motorb...kyard-dog.html

Regards,
Eric

[ringoism]

When I walked into the Hero showroom today, the salesman asked whether I had need of any more Impulse bikes, saying the company STILL has unsold stock that they're wanting to sell at a discount. In this case the Rs5,000 discount quoted was far from being enough to tempt me (68,000 total), but just throwing this out there for any others who might lament having missed buying this bike when it was earlier on offer. RE's Himalayan, if early sales are any indication, seems to be on its way to a great success and will certainly overshadow the Impulse's brief entry... but the smaller machine is still a good one in many ways and has a few advantages (especially the lighter weight for trails, etc) - and at sub-Rs70,000 costs well under half what the RE does.

I have some basis for comparisons now - Just spent six days out traveling on mine alongside the Himalayan and various other RE's, traveling Manali-Leh-Tso Moriri and back.



I'll confess that as it regards the idea of Ladakh runs, the thrill had been gone for some time now; I'd been over the road several times already, and as late it seemed to have become rather overrun and I assumed a bit "sanitized" besides (a couple years ago Sumo taxis were managing to complete the run in as little as 12-13 hrs, vs. a solid 18 earlier). Moreover Leh itself had degraded (vs. my first visit in 2005), turning overcrowded and over-commercialized; Add to that last year's shameful local hyper-protectionism (Leh taxi & bike rental mafias), and there was really very little appeal left for me. But Delhi-based friends for whom this represented a first-time challenge were keen on having me (as something of a veteran, I suppose) along, even offering to pay my expenses... so in the end the promise of good camaraderie proved too difficult to resist.





My negative sentiments about the route and destination had actually not been much different two years ago when I went, at that time taking the then brand-new Impulse along, which on that occasion had performed rather miserably. And yet I'd come back smiling; the road was NOT sanitized - NOT easy; Not even "safe" I suppose, still lacking lane markings anywhere, or guardrails in even the most dangerous of places. And it had been early in the season then (only the second day after Baralacha-La had opened), and there was still plenty of adventure to be had, particularly in the form of snowy/icy passes and a ridiculous, huge water crossing or two. This time proved to be equally satisfying in its own ways. The road is still BAD in many places, still challenging, still beautiful, still remote, still – if truth be told – quite dangerous potentially at many points.






And the best part of it - what was "new" this time - is that while I'd never before traveled in group larger than 2-3 vehicles, this time there were seven of us on bikes, including three new RE Himalayans (a matte black trio), a gleaming AVL 500 Machismo (truly "King of the Mountain"), two Electras, and my displacement-challenged yet favorably lightweight Hero. Four other travelers rode in an accompanying Xylo...



My primary practical role was as a sort of mechanic / guide, for which my presence proved helpful on an occasion or two, and being part of a group, it turned out to be a very different experience from previous rides to be sure - and a very good one. Basically this was just a great bunch of guys (and one gal) to travel with; they know how to enjoy life, and whether riding, chatting, enjoying a meal, kidding around with one another, there’s a healthy spiritual thread running through all of it.






I won't give a full ride-report here since many others on other machines and occasions have done so, and since - in the words of one of the more accomplished riders of our group - "It doesn't matter how much you've read in the forums / blogs about this road and the places and experiences along the way; you really have no idea what it's like till you've seen it for yourself".

But as the route provides a wonderful (if punishing) proving ground for machines (not to mention the human body), I'll mainly comment on them here, and just briefly:

The Impulse:





My little bike ran splendidly then entire way, with hardly a hiccup - there really is something to be said for getting one's tuning sorted. Being at a 200-350cc disadvantage compared to the other machines in our group, I'd feared I might be holding the others up; and if the bike had been running as badly as it did two years ago, that would've been a valid concern (that time, I was literally praying I'd make it to the top of each higher pass, and was barely succeeding). But thankfully my "disadvantage" was a complete non-issue this time, and in fact much of the time the bike and I were comfortable at a more rapid pace than most of the rest of the group.



The 15T (CBZ Extreme?) front chain sprocket had worked well going up Rohtang, making 2nd gear feel a lot more useable and the rest feel a lot closer-ratio; but I felt it was going to be too limiting on the well-paved roads in Lahaul, and more so on the high-speed plains at Moray and the last couple hours into Leh; so at Jispa I'd put the original 17T back on, definitely the better choice. Even with that (and the oft-cited big 1-2 gap), I had no trouble on inclines anywhere, accelerating just fine out of hairpin turns and maintaining around 50-60kmph on straights ascending the highest of the passes (Tanglang-La); I even successfully managed, with my 20kg luggage and 80kg self, a couple of the shortcuts at the Gata Loops (could've dared all of them with the 15T!), and eventually saw 104kmph on the Moray plains (slight downhill and likely a tailwind!). I'd hoped to ascend to Kardung-La and have no doubt the bike would've managed it, but as most of the group members were bound by commitments back in Delhi, we lacked the time for it. Maybe next time…

Pre-travel bike prep wasn't extensive:

* Tightened up the steering head "cone" bearings (they'd been holding well for quite a while, but on-center wear was now becoming apparent and would prove irritating for the duration of the trip);

* Changed the engine oil;

* Installed the 15T front sprocket (just to see how it would run vs. the original 17T), and tightened/lubed the chain after shortening it a couple links (very perplexed to discover that the factory chain had no master link!???);

* Mounted up a new MRF Mogrip Moto-D rear tyre (100/90-17 vs. the original's 110 cross-section, so a tad shorter).



The CEAT (Gripp-XL) had enough tread left but concerningly was cracking very badly in the sidewall; front CEAT was likewise cracked, but just prayed it would hold out till I could get my 21" wheel conversion done (as seen below - just waiting for the spoke nipples now):



The Moto-D seems to be a softer compound than earlier MRF's, has pretty big void areas with a lot of radial grooves to help prevent fishtailing / lateral slip in the loose stuff, lateral grooves to assist forward motion/braking off-pavement, and it runs quieter than the CEAT's, too. Felt a little "squirmy" on-road initially - which would be expected with the narrow blocks and deep grooves, but after 1200km on all sorts of surfaces, VERY pleased with the performance. Short of really slick/deep/clayey mud, it basically just never loses traction. Could've wished it was available in either the 110/90 or 120/80 size, which would be closer to stock width/diameter; the 100 looks a little skinny and gives up just a little ground clearance (technically 0.9cm), but in truth it works great. I'd considered the Ralco Gripper, also in the 100/90 size, which would've cost Rs500 less and matched the tyre tread soon to be up front - but I suspect the aggressive tread would've been overkill, and on-road I'd not expect it to wear as well, run as quiet, grip as firmly, or deliver as much FE as the MRF.

* Re-jetted the carb to a #125 main (high speed) jet, vs. the 129 I'd been running around Manali. The main needle was already dropped 0.75mm by shaving down the top retaining flange to 0.85mm thick vs. the original 1.60mm - had finally got this sorted out after my Spiti run a year ago, and rather than shimming it back up again, had just been running around a little leaner (in the midrange) locally, which was good for FE anyway.

* Installed a slightly-hotter-than stock NGK CPR7EA9 plug (the "7" is a range hotter than the "8" of the original CPR8EA9, and as such would help keep the carbon burnt off the electrode in the event of some over-rich mixtures on the high passes).

* Changed the original front shocker oil to a lighter (desi-type) grade, which really softened up the ride quality a lot, and seemed to still offer good control.

The Machismo 500 AVL:

No pics of this one, but anyway: It is said that these run better at altitude than the new 500 UCE's, whether carb'd or FI'd. One local tour operator claims it is the higher compression ratio, and has not made the switch to the UCE's or Himalayans simply because his foreign clients really want to ride hard and fast, and this is allegedly the strongest-running option out there. I don't know, but what I do know is that everyone in the group was impressed with it. The owner was lucky to pick up this pristine, low-mileage (under 10k km's done) bike from a friend a few years ago for Rs80,000. It would seem to represent the Bullet's finest hour, and one of the more skilled / experienced riders in our group, mounting it after some hours in the saddle of his own Himalayan, said it just felt so strong - and surprisingly, even "plush". I might try and pick one up myself someday.


The Electra (UCE) 350's:



A 2009 and a 2015. Amazing how these bikes simply get the job done. Not fast, not powerful, but steady, willing, and surprisingly economical to fuel. I witnessed that a skilled (slightly mad?) rider can thrash one and hang in there with an equally hard-ridden Himalayan over the rough/loose patches.



But the bike is made for plodding along, and if you like to plod, who's to criticize? Plod on! It was the riders of these Electras who, having separated from the larger group, accompanied me on the TsoMoriri/TsoKar circuit. These bikes don't do anything for me personally and I wouldn't really want to be riding one myself, but it's indeed impressive that such an old and somewhat compromised design can still be so feasible in the modern age, that it can manage what it does best (i.e., plodding) on just about any surface, in any weather, at any altitude, with any amount of luggage, etc. Probably at least 80-90% of what you find out there on this route are UCE350's, and that is really saying something.







The RE Himalayan:

One was a rental, another was owned by one just returning to biking after a ten-year hiatus, having only done 300km before embarking on this journey; the third was guided by a pretty capable rider who's been in and around the bike scene (incl. vintage) for years, who recently sold his H-D and bought a Triumph Tiger, which he also plans to tour on; for him this seemed a test-run, an exercise in curiosity. I rode his bike for awhile in Lahaul, and observed him and the others over hundreds of km's thereafter. A few thoughts:

1) I can see where the appeal attached to previous RE's generally applies here too: Everything seems substantial and solid. Very little plastic to be found anywhere. Rear mudguard doesn't flap and shake around on every bump like my Impulse's does. Instrumentation attractively exudes quality. Steering feels absolutely planted on center, as Bullets always have felt. The bike is heavy (overweight?) and just feels like it's going to be around for a long time - it is not a throwaway piece. The engine / gearbox are still not very refined, but so what??? It's probably just about the only new market entry that's still got a round headlight. And like a Bullet, the design just may prove timeless - not at all gimmicky, and likely to still look good ten or twenty years from now.

2) I can see where RE traditionalists could hate it: It is just not a thumper at all, not a "plodder". It's got strong midrange / some upper rpm power, and a nice "surge" when you get into it. Oh, and it's got less vibrations than anything before it. Oh my, the headlight doesn't turn, and when parked with the handlebar to either side, it looks like it's been in a horrible accident (a local up here told me). Just awful, how could RE make a bike like this??? It is obviously not a Bullet. So "they" will say (well, forget "them").



3) In my own (hopefully open-minded) assessment: Honestly the bike's too heavy, the rear suspension's too hard (my bum and those of the others kept jumping off it on rough patches). For a tall guy like me the seat's too low in relation to the footpegs, leaving my knees excessively and uncomfortably bent. The engine (still) lacks refinement. Gears are a little noisy. Ground clearance is much less than it would appear, once someone's seated on the bike and the suspension is settled down (to my shock, I managed to scrape bottom on a lowly speedbreaker). The rear disc brake is excessively sensitive for rough-road use, meaning that it is too easy to lock up the rear wheel simply by inadvertently touching the pedal whilst getting bounced around on a loose, bumpy track. The carb’d engine does lose power at altitude; one of the three bikes was already affected at Manali, and at the Moray plains wouldn’t do above 70kmph.

A re-jet at Leh (from a 125 down to a 110 main) took care of that, whereupon my Impulse was again left in the dust, feeling comparatively so sluggish. RE’s Leh service center has a TN red-plate bike sitting inside with some mods (threaded fitting in the header pipe, presumably for an O2 sensor) that point to the prospect of a Proper FI system in the coming days. If they do it right this time (unlike the 500CL’s/TB’s notorious half-baked and unreliable Keihin system), it can be a plus.

On the positive side, the power delivery provides great fun, the 21" wheel and appropriate shock valving have the front end gliding nicely over everything, and the windscreen really does an effective job of reducing turbulence and buffeting around the rider. The bike can be ridden hard if so desired, in which it can cover a lot of ground on nasty roads pretty briskly. Only caveat being that you've got to stand on the pegs if you don't want to injure your back. In which case you could just do the same on a Bullet or a Pulsar or whatever, I guess...


Despite my complaints though, I think the bike is a winner. We saw dozens, if not hundreds, of them out there on the Manali-Leh road already. The machine is unique in the world of biking - a motorcycle purpose-built specifically with its home market and its own type of touring in mind, its own tastes, its own type of legacy. It is not perfect, but it may prove a sort of “cult” bike, an image-maker, and besides that it seems a decent all-round tourer. It can certainly be improved upon / enhanced / purpose-refitted by the aftermarket, if modern-day RE owners prove willing to take that plunge. Let’s see what happens. All in all, I feel I wouldn’t mind owning one myself.


Earlier there were those who claimed “every biker falls down on their first trip to Ladakh”. In those days you had the deep dusty trails through the Moray Plains, and none of the present improvements on the south side of Baralacha La or both sides of Thanglangla, and I suppose there were more risks. All that to say that of the six bikers amongst us for whom this was a first-time experience, ONLY three fell down (though it could be mentioned that two more got themselves stuck in crossings);


As for the seventh rider for whom the trip would represent the 7th and 8th crossings of the terrain after Tandi (Lahaul): Well, around ten kilometers from home on a wet hairpin turn, on a stretch covered countless times previously, he too finally “made his mark” – ending up belly-down on the pavement unable to move, his right leg pinned under the fallen machine.

I could feel the effects of the impact on my right knee/elbow, right ankle, and left thumb… but thanks to God, no real injuries at all. My gloves, though thick leather, were not of the armored variety, but everything else was proper riding gear – I was pleased in particular that I’d gone to the trouble and expense of getting those Sidi riding boots from abroad, for whom this was a maiden voyage. Not cheap but they ultimately proved their worth.

Guess I should've realized that the sidewall cracking in the front tyre would naturally be indicative of hardened, less grippy rubber...



and I shouldn't, in my eagerness to reunite with my dearly missed wife / boys, have been pressing so hard - or tailgating the Army bus that so suddenly stopped in its tracks...

As for the Impulse, it got away with a few minor scratches on the front mudguard (have an extra anyway) and the headlight fairing.




All in all, a very positive experience and entry into the world of group riding.

Regards,
-Eric