[JayPrashanth]

Originally Posted by Beast_of_Burden

So, there is a difference between 4s and 5s. the 5s does higher speeds at lower rpm compared to the 4s. Please confirm that I am reading this right.

By the same token, the 5s would cruise slightly more relaxed than the 500 CI by about 5%. The 500CI would be doing 100 kph at 4000 rpm while the 5s would be doing the same speed at 3800 rpm.

The calculator comes up with a top speed of 124 kph at 5000 rpm for the 500 CI and a top speed of 131 kph at 5000 rpm for the 5s. Are these numbers plausible?

Plausible only on paper. You would be hard pressed even to do a genuine 110 on the 5S, let alone 130. The 4S will max out at genuine 100 or if pushed, 105. Now, from where did the CI500 come into the picture? Though the 5S should be more fuel efficient, in reality, it is one of the most thirsty bulls. The STD350 and 4S deliver better mileages than the 5S. Lot's of 5S owners report low mileage issues. Check the RE bulletin board out.

And about the 4Ss being less available in the used market, RE stopped selling 4S long ago in most of South India barring Kerala. RE sells 4S only in North India now.

Cheers,

Jay

[bj96]

Originally Posted by Beast_of_Burden

So, there is a difference between 4s and 5s. the 5s does higher speeds at lower rpm compared to the 4s. Please confirm that I am reading this right.

Correct. For same speed, 5s does a lower RPM. But difference is not very apparent to inexperienced rider... in fact me too haven't ridden a 4S myself for any considerable destance. Hence can't compare the feel against 5s.

Originally Posted by Beast_of_Burden

The calculator comes up with a top speed of 124 kph at 5000 rpm for the 500 CI and a top speed of 131 kph at 5000 rpm for the 5s. Are these numbers plausible?

Originally Posted by JayPrashanth

Plausible only on paper. You would be hard pressed even to do a genuine 110 on the 5S, let alone 130. The 4S will max out at genuine 100 or if pushed,

In stock form, CI Bullet engines can't ve revvd beyond 4Krpm when put on road. In fact on my 5s I see it laboring around ~95 KPH (about 3800 rpm) and only on a very long open stretch does it go past 100 kph (~4000 rpm). Probably, by adding some mods like free flow air filter, upjet carb, free flow exhausts, bigger oil pumps etc, they can be made to rev beyond 4k rpm. Factory specs of max 5.5k rpm is too optimistic- it redlines much before that.

Originally Posted by JayPrashanth

Though the 5S should be more fuel efficient, in reality, it is one of the most thirsty bulls. The STD350 and 4S deliver better mileages than the 5S. Lot's of 5S owners report low mileage issues.

Don't recommend hearsay. Lot of 5s owners do not know how to tune their bikes or their bikes may have some serious problem or the way they ride. Mine consistently returns 33-36 KPL in Pune city. It can be leaned a bit further- but, I am happy with it. On my last trip to Daman via NH-4, it returned me ~43kpl (600 kms in 14 liters).

-BJ

[Rennjit]

Originally Posted by JayPrashanth

...Though the 5S should be more fuel efficient, in reality, it is one of the most thirsty bulls. The STD350 and 4S deliver better mileages than the 5S. Lot's of 5S owners report low mileage issues...

Caused by a difference in gearing?
Seems 18T(?) sprocket is too much for a 350CI engine necessitating bit more throttle input for normal riding than with a 4S box thus lowering mileage. + the 5th gear behaves like an overdrive, min 50kph else downshift.

Any have info on gearbox internal ratios, ie., for 1,2...5?
& whats the max sustainable Rpm's CI & avl engines are capable of?

[JayPrashanth]

Originally Posted by bj96

Don't recommend hearsay. Lot of 5s owners do not know how to tune their bikes or their bikes may have some serious problem or the way they ride. Mine consistently returns 33-36 KPL in Pune city. It can be leaned a bit further- but, I am happy with it. On my last trip to Daman via NH-4, it returned me ~43kpl (600 kms in 14 liters).

-BJ

What makes you think I am recommending hearsay and what exactly does tuning the bike mean? Leaning the mixture is it? If you are getting mileages of 40+ on your CI, you are running too lean or you are riding at a constant 50-60 on a highway. Most people on 5Ss go to their mechanics and ask for maximum mileage. The mech leans the mixture and they plod around the city with their bulls overheating. In the long run, your engine life would be affected. If your bull struggles to reach 95, then it is running lean or there is some other issue preventing it from performing optimally. BTW, how exactly have you measured the RPMs? Running a tacho?

Also, the mods you have listed won't shift the range of rpm to higher levels. Rather, they would help the engine breathe better thus liberating the power that has been lost due to the restrictive intake and exhaust system. ant the increase in power would be apparent across the rev range. If these mods were to let the bullet rev higher, the top speeds should go up, which isn't the case. Please correct me if I am wrong.

Cheers,

Jay

[bj96]

Originally Posted by JayPrashanth

What makes you think I am recommending hearsay

because you said "lots of 5s owners".... I am talking from my experience, not about "many owners" on some forum.

Originally Posted by JayPrashanth

and what exactly does tuning the bike mean? Leaning the mixture is it? If you are getting mileages of 40+ on your CI, you are running too lean or you are riding at a constant 50-60 on a highway.

I know what is leaning and who told you its always bad? Most vehicles are tuned to the leaner side than vehicles of past, including bullets...but then there are limitations of such a tuned engine- the rider should know. I have four vehicles and Bullet seats idle for months at a stretch. Still it starts one kick, every time- 1st sign of a sweetly tuned engine. Please pay attention to my original post. I said 33-36 in city (40+ was on highway). Yes I ride it in economy range- it goes with my style of riding. 65-70 km/h is the sweet spot for my 5s.

Originally Posted by JayPrashanth

If your bull struggles to reach 95, then it is running lean or there is some other issue preventing it from performing optimally.

Optimum speed of a Bullet is not 95 KM/h. For that matter no Indian made bikes have optimum speed of 95 km/h yet. My Bullet does reach 100 km/h, but, certainly it is not its optimum speed.

Originally Posted by JayPrashanth

BTW, how exactly have you measured the RPMs? Running a tacho?
Also, the mods you have listed won't shift the range of rpm to higher levels
...

You missed the whole context. Refer my earlier posts. If you know the gearing ratio and wheel dia- there is a simple arithmetic calculation to find the RPM and vehicle speed. You do not need tach for that. A speedo will be good enough to find the rpm reasonably accurate. Tacho is useful only to find the idling rpm or when you do not know the gearing and wheel dimensions.

The mods I suggested will NOT change the RPM or gearing ratio, but, it will certainly help engine breathe easier and reach 4000+ RPM easily and that's how it will reach higher speeds (>100 km/h) easily. Stock engine do not breathe easy, gets heated due to insufficient oil flow- hence, they do not go 4000+ RPM easily.

Looks like you have not done practical on the internals of drive/power train of a Bullet ever. Do you really ride one or just read about them?

Lets not go off-topic. Modding bullets need a different thread. Here we are comparing Std (4s) and 5s purely as it comes stock.

-BJ

[Rennjit]

Originally Posted by bj96

...In stock form, CI Bullet engines can't ve revvd beyond 4Krpm when put on road. In fact on my 5s I see it laboring around ~95 KPH (about 3800 rpm) and only on a very long open stretch does it go past 100 kph (~4000 rpm)...Factory specs of max 5.5k rpm is too optimistic- it redlines much before that...

Now that's some serious allegation against RE if CI engines do not revv to the claimed max power rpm of 5K. This means RE is selling products with hypothetical claims ie., 18hp @ 5000rpm.
Or does power also comes under the 'std test conditions' tag like mileage?
I read from your post that a stock CI never reaches this rpms, can you pls validate?

[Beast_of_Burden]

Originally Posted by Rennjit

Now that's some serious allegation against RE if CI engines do not revv to the claimed max power rpm of 5K. This means RE is selling products with hypothetical claims ie., 18hp @ 5000rpm.
Or does power also comes under the 'std test conditions' tag like mileage?
I read from your post that a stock CI never reaches this rpms, can you pls validate?

Exactly my thoughts, RE has been getting away with making hypothetical claims for this long? But then there might be credence to this, a 100 kph top speed for a relatively large engine never did make sense to me.

Might be , but it leads us to the next question, what is the UCE in the TBTS like in this regard? Assuming the goal is a comfortable cruising speed of 100 kph, how does it feel subjectively in comparison to the CI models (i will leave the AVLs out of the picture).

Please share your riding impressions of the TBTS. To be utterly frank, I have no interest in the T-bird or the Classic, only the new engine.

[Ravveendrra]

Originally Posted by bj96

Follow your heart. Since, you like classic bullet configuration of gear shift and brakes- go for 4S. You will not regret it. Just a little tip 4S uses the same gear box from old std- they are prone to leak- minor issue for a bullet

.....

It is a similar thingy called "distributor" in cars of yore. The difference is in number of cylinders. Cars, except Tata Nano, have usually 3+ (current is distributed between cylinders in some finite firing order- hence the term) while bullet has a single cylinder- no distributor. In a nutshell, by tweaking the CB gap/angle you can advance and retard the spark plug firing (ignition timing) causing the engine to behave and perform differently. Depending on your needs, e.g. for high speed and high load riding you may like to advance the timing. Do opposite if you like the sedate ride and fuel economy.

....

I agree, for the real retro 'big banger' feel stick to the classic.

About setting the CB points / distributor (called delco after the most common brand in the initial days) - Ignition set to 'advance' will give great initial pick-up and the engine will run hotter. Great for within city (short rides / drives) the engine will seem 'out of breath' at higher rpms. Setting them to retarf on the other hand will make it sluggish initially but there will be a 'kick' at the end, something akin to turbo-lag. The engine will run cooler and really come into its own at higher revs. Set to retard only if you like revving your engines and do long highway stretches. If you like winning the signal drag set to advance.

Experiment around a bit before you find the setting that suits you, setting the CB points / distributor is mainly advance/retard but also involves 'gap' between the points and the vaccum advance (if present). Once the timing is right - proceed to set the air/fuel mixture. Advance will normally prefer richer mix while retard will tolerate a leaner mix. Once you find the correct timing and carb setting to suit your style of riding - you will be one step closer to motoring nirvana.

Cheers,

[bj96]

Originally Posted by Rennjit

18hp @ 5000rpm. Or does power also comes under the 'std test conditions' tag like mileage?I read from your post that a stock CI never reaches this rpms, can you pls validate?

Well I can't really validate it since I do not have equipments to do this. However, a little arithmetic (with gear ratio known and max road speed of about 100 km/hr) suggests that max stock engine RPM on road would be about 4000 i.e about 80% of rated max power output. That means 5000 rpm probably is on a stationary motor with no load to haul However, since, it produces max torque at about 3000 RPM, in the 2800-3500 band- engine feels relaxed and can donkey day long in this range.

Btw, other manufacturers, e.g. Bajaj claims about 17BHP @8500 RPM for a Pulsar 180. Does stock Pulsar engine reach 8500 RPM on road? Where does it redline?

Originally Posted by Beast_of_Burden

a 100 kph top speed for a relatively large engine never did make sense to me.

Lets not forget, that CI engine was designed in 30s when hitting 80 km/h was probably greatest dream. For a motor with such long strokes and so less CR (~6.5), I guess, 100 kph is ok. Stock CI Bullet is certainly not a speed daemon, but, @70KMPH with its lazy rhythmic beat, it is ultimate nirvana on road. If you are into racing and like sprinting, a Bullet will disappoint you, but, if you are into marathon touring, Bullet outshines others*.

-BJ

*PS: From my experience- I have owned RXZ (4s) for about eight years and have ridden Splendour(1st gen), CBZ (1st gen) and Pulsar 150 (2nd gen) extensively other than Bullet- all stock.

[JayPrashanth]

Originally Posted by bj96

I know what is leaning and who told you its always bad? Most vehicles are tuned to the leaner side than vehicles of past, including bullets...but then there are limitations of such a tuned engine- the rider should know. I have four vehicles and Bullet seats idle for months at a stretch. Still it starts one kick, every time- 1st sign of a sweetly tuned engine. Please pay attention to my original post. I said 33-36 in city (40+ was on highway). Yes I ride it in economy range- it goes with my style of riding. 65-70 km/h is the sweet spot for my 5s.

Ever cared to find out why leaning is bad? FYI, drag setups run slightly lean because they make maximum power when they are set up just a wee bit lean. That said, lean is not good for street engines, especially in our hot, sultry high traffic conditions. If you ride sedately, then it doesn't really matter as you really won't be stretching it. And a perfectly tuned engine usually will require a choke to start. So, kindly know what you are talking about before saying something.



Optimum speed of a Bullet is not 95 KM/h. For that matter no Indian made bikes have optimum speed of 95 km/h yet. My Bullet does reach 100 km/h, but, certainly it is not its optimum speed.

You also should read what I write. Optimum performance is different from optimum speed. To make it easier for you, optimum performance also considers the entire rev range.


You missed the whole context. Refer to my earlier posts. If you know the gearing ratio and wheel dia- there is a simple arithmetic calculation to find the RPM and vehicle speed. You do not need tach for that. A speedo will be good enough to find the rpm reasonably accurate. Tacho is useful only to find the idling rpm or when you do not know the gearing and wheel dimensions.

Gets heated due to insufficient oil flow- hence, they do not go 4000+ RPM easily.

Wow, news to me.

Looks like you have not done practical on the internals of drive/power train of a Bullet ever. Do you really ride one or just read about them?

I don't need to answer this. Let us assume you are an expert with the Bullet's internals. How exactly did you come to a conclusion that the Bullet revs only to 4K rpm with the stock speedo. Any bulleteer worth his salt will know how accurate the stock speedos are. And coming to a conclusion regarding the rpm from the stock speeds, and accusing a manufacturer about it's engines not meeting the claimed figures is plain absurdity, methinks.

Lets not go off-topic. Modding bullets need a different thread. Here we are comparing Std (4s) and 5s purely as it comes stock.

May I remind you that you brought the topic up gentleman.

-BJ

Cheers,

Jay

[JayPrashanth]

Originally Posted by Rennjit

Now that's some serious allegation against RE if CI engines do not revv to the claimed max power rpm of 5K. This means RE is selling products with hypothetical claims ie., 18hp @ 5000rpm.
Or does power also comes under the 'std test conditions' tag like mileage?
I read from your post that a stock CI never reaches this rpms, can you pls validate?

Originally Posted by Beast_of_Burden

Exactly my thoughts, RE has been getting away with making hypothetical claims for this long? But then there might be credence to this, a 100 kph top speed for a relatively large engine never did make sense to me.

Might be , but it leads us to the next question, what is the UCE in the TBTS like in this regard? Assuming the goal is a comfortable cruising speed of 100 kph, how does it feel subjectively in comparison to the CI models (i will leave the AVLs out of the picture).

Please share your riding impressions of the TBTS. To be utterly frank, I have no interest in the T-bird or the Classic, only the new engine.

Guys, please don't jump the gun and start pointing accusatory fingers at RE. We are on team-bhp, a forum which is taken seriously by manufacturers. Such comments without proper proof to substantiate will show us in poor light. BJ-96 cannot validate since he isn't using a proper tach to measure rpms, simple. 100kph for a "big" engine does make sense if it designed in the 1930s, not in 2009. Another reason is the lack of standardization at RE. CI machines are handbuilt at Tiruvottiyur, and this along with poor quality control is one reason why there isn't consistency in the performance of CI bulls. Don't worry about the UCE. The UCE is much better finished, engine wise than any CI. Meanwhile, the Redditch 350s used to do a genuine 120. One major reason is because they ran a completely different port geometry. In layman terms, the ports on the Redditch made 350s was a V opposed to the inverse V on our Indian bullets. This also explains why our Indian bullets can't be ported, but only polished.

The UCE500 can cruise at "genuine" 100, or even 110 all day long. Why, even the AVL500 can do a 100 all day. You could cruise at a genuine 90-100 all day long on the UCE350. And the figures for the UCE350 and the AVL500 aren't measured on the stock speedo. So, the "genuine" part.

Cheers,

Jay

[JayPrashanth]

Originally Posted by bj96

Btw, other manufacturers, e.g. Bajaj claims about 17BHP @8500 RPM for a Pulsar 180. Does stock Pulsar engine reach 8500 RPM on road? Where does it redline?

Manufacturers in India claim power-rpm figures at the crank, not at the wheel.
The Pulsar with 17bhp at the crank would make around 13RWHP.

Cheers,

Jay

[bj96]

Originally Posted by JayPrashanth

BJ-96 cannot validate since he isn't using a proper tach to measure rpms

Originally Posted by JayPrashanth

Cheers,
How exactly did you come to a conclusion that the Bullet revs only to 4K rpm with the stock speedo.
Jay

I reiterate, you do NOT need a tacho to determine engine RPM at any vehicle speed (KM/hr) Provided you know the gearing ratios and the wheel diameter. The values would be reasonably accurate based on simple aritmetic calculations. Hope you will appreciate these simple equations:

Vehicle speed (V) = displacement (S) / time (T)

S = wheel rotation x n // n is number of rotations.

V = k x (wheel rotations/time) // K is a constant factor depending on wheel diameter.

Wheel rotation = g x (Engine rotations /time) // g is a constant on gearing ratio

Hence,
V = k x g x (engine rotations /time) // engine rotations/time aka RPM

i.e.

V = k x g x RPM

Or

RPM = V / (k x g);

If you know V (velocity of bike) and "k" and "g" too, you can find the RPM. If you do not follow above equations- pls google "engine rpm vehicle speed gear ratio formula" etc.

By its own admission (RE website/tech specs in user manual) max speed of CI 350 Bullet is 100 km/h, hence, you can calculate its (max) RPM w/o looking at tacho. Off-course assumption is no clutch slip. Now, for a Bullet use following parameters (T= teeth) for stock gears/sprockets:

[REPOST]
Engine= 25T
Clutch= 56T
top gear (4th/5th) teeth = 16T for 4s and 18T for 5s gear box on CI 350
Rear wheel sprocket teeth= 38T
Wheel diameter = 26"

Go to this website Modern Motorcycling Ltd. | Suzuki Motorcycles, Ratio's Page, 'Dealer of Choice!' and enter above values, change RPM to find the vehicle speed at the bottom of the calculator.
[/REPOST]

Does it help?

Originally Posted by JayPrashanth

Manufacturers in India claim power-rpm figures at the crank, not at the wheel
Jay

Well then 18 BHP for CI 350 would be at crank (no load) which translates to 80% at wheel (4000 rpm max=100KPH) when running on road.

-BJ

[JayPrashanth]

Originally Posted by bj96

I reiterate, you do NOT need a tacho to determine engine RPM at any vehicle speed (KM/hr) Provided you know the gearing ratios and the wheel diameter. The values would be reasonably accurate based on simple aritmetic calculations. Hope you will appreciate these simple equations:

Vehicle speed (V) = displacement (S) / time (T)

S = wheel rotation x n // n is number of rotations.

V = k x (wheel rotations/time) // K is a constant factor depending on wheel diameter.

Wheel rotation = g x (Engine rotations /time) // g is a constant on gearing ratio

Hence,
V = k x g x (engine rotations /time) // engine rotations/time aka RPM

i.e.

V = k x g x RPM

Or

RPM = V / (k x g);

If you know V (velocity of bike) and "k" and "g" too, you can find the RPM. If you do not follow above equations- pls google "engine rpm vehicle speed gear ratio formula" etc.

By its own admission (RE website/tech specs in user manual) max speed of CI 350 Bullet is 100 km/h, hence, you can calculate its (max) RPM w/o looking at tacho. Off-course assumption is no clutch slip. Now, for a Bullet use following parameters (T= teeth) for stock gears/sprockets:

[REPOST]
Engine= 25T
Clutch= 56T
top gear (4th/5th) teeth = 16T for 4s and 18T for 5s gear box on CI 350
Rear wheel sprocket teeth= 38T
Wheel diameter = 26"

Go to this website Modern Motorcycling Ltd. | Suzuki Motorcycles, Ratio's Page, 'Dealer of Choice!' and enter above values, change RPM to find the vehicle speed at the bottom of the calculator.
[/REPOST]

Does it help?



Well then 18BHP for CI 350 would be fine at crank which translates to 80% at wheel (4000 rpm max).

-BJ

I agree sir. But, the tacho, an electronic one at that, still remains the most "accurate" way to measure rpms. This becomes even more pertinent, especially when you are talking Enfields, what with their ported speedos-the easiest go faster mod, haha. So, since the speedos are highly inaccurate, the rpm reading naturally go for a toss. Hence, I was crying hoarse. Nothing new with the method though. The equations take me straight back to my 8th standard.

The gearing determines speed-rpm. So what is it about CIs not revving upto 5500rpm. As manufacturers mention power-rpm values at the crank, won't 5500 be plausible. Here, we have our fellow BHPians questioning stuff vaguely. So, I had to come out and explain how it is done. I just did that.


Cheers,

Jay

[EssYouWe]

@BJ and Jay

Stop this futile argument. We regard you guys as experts. Insane arguing does not bode well for your images.

@BJ
We all understand the math you are using. Believe me.. even a 6th grader would.

However, the point remains that it is a commonly accepted belief that mobike speedos are inaccurate and usually too optimistic.

Also most of your relations are linear. I agree that is how they are, but failing to take into account any t-losses and existing retardants we can't conclude the difference in power with a lot of confidence.

All said, your analysis has been an eye-opener. I never looked at the issue from this side.

@Jay

Relax man! No one is going to point unjustified fingers at RE.


Now please break up this argument.

Lets get back to 4s v/s 5s.