[navin_v8]

Originally Posted by ashwinprakas

Other motorcycles rev way higher all the way up to 12k and have gear ratios even wider apart, also to note is that RE's don't have overdrive gearing.

Mate on the contrary RE's do have overdrive gearing, as far as I know all RE's do have an final overdrive gear i.e. 4th gear in 4 speed transmission (including CI and AVL), 5th gear in 5 speed (including AVL and UCE) both for 350 and 500cc models.

From what I know, Overdrive gear is related to any automobile going at a constant/sustained speed(read cruising) at relatively lower rpm's to put less load on the engine compared to lower gears at high rpm's at the same speed. As we are talking about rev matching and downshifting another phenomenon that comes to mind is about old RE CI's going as low as 20-30 KMPH on top gear(4th gear) all the way up to 60-80-100 KMPH in the same gear(4th gear). While some may say it is harmful to the engine and transmission, yes it is, but that's not the case with old CI's (especially heavy crank ones). Heavy crank coupled with flat torque curve negates the need for downshifting, especially on an old 4 speed CI Bullet 350/500.

[ashwinprakas]

Originally Posted by navin_v8

Mate on the contrary RE's do have overdrive gearing, as far as I know all RE's do have an final overdrive gear i.e. 4th gear in 4 speed transmission (including CI and AVL), 5th gear in 5 speed (including AVL and UCE) both for 350 and 500cc models.

Overdrive is when the gear ratio is below 1:1.

On other motorcycles 3rd gear is usually 1:1 and gears beyond that are overdrive.

On the Royal Enfield's the last gear is 1:1, so basically it doesn't have overdrive.

This is something I'd learnt from TBhp as before I presumed even RE's had similar ratios as other motorcycles.

[rdst_1]

Originally Posted by nitro.1000bhp

So, I always pull in the clutch, wait for the rpm to drop and only then can i shift.

Isn't that dangerous.?With the clutch pulled in, the bike loses traction. So if you are taking a turn or have to use the brake, it becomes very unsafe. I learnt that the very first time, I was riding a bike, a 97 CI 4-speed Bullet 350. So, I either use the brakes or engine braking to slow down and then downshift as needed in a swift movement which doesn't require pulling the clutch for more than a second.

[srini1785]

Originally Posted by rdst_1

Isn't that .....

+1

Especially when driving down a slope. Best practice is to brake engine directly with clutch engaged and pull clutch only when shifting. This applies equally to cars and bikes.

PS : Learnt this the hard way here in tbhp.

[nitro.1000bhp]

Originally Posted by rdst_1

Isn't that dangerous.?With the clutch pulled in, the bike loses traction. So if you are taking a turn or have to use the brake, it becomes very unsafe. I learnt that the very first time, I was riding a bike, a 97 CI 4-speed Bullet 350. So, I either use the brakes or engine braking to slow down and then downshift as needed in a swift movement which doesn't require pulling the clutch for more than a second.

Relax. I always finish the downshifting and braking bit before entering any turn. I know it's dangerous to have the clutch pulled in a turn. It is also dangerous sometimes to shift gears or brake in the middle of a turn , specially on old bullets with square tyres...

Anyhow I think the old bull's clutch is on its way out. It's not my daily ride... I'll fix it when I find time.

[tharian]

Originally Posted by navin_v8

Mate on the contrary RE's do have overdrive gearing, as far as I know all RE's do have an final overdrive gear i.e. 4th gear in 4 speed transmission (including CI and AVL), 5th gear in 5 speed (including AVL and UCE) both for 350 and 500cc models.

Originally Posted by ashwinprakas

On the Royal Enfield's the last gear is 1:1, so basically it doesn't have overdrive.

This is something I'd learnt from TBhp as before I presumed even RE's had similar ratios as other motorcycles.

I don't think it is even 1:1 on the old 4 sp gearbox. This is from the good old manual for all the 350's and 500 Bullets of early 2000.
Not sure if 'overall ratio' is different from gear ratio.

EDIT:
I stand corrected. It is 1:1. Thanks to keroo1099 for sending me his Bullet manual which is older than mine.

[navin_v8]

Originally Posted by ashwinprakas

Overdrive is when the gear ratio is below 1:1.

On other motorcycles 3rd gear is usually 1:1 and gears beyond that are overdrive.

Yes and as per definition overdrive is related to speed vis a vis rpm. Meaning the vehicle can cruise at continuous high speeds at relatively lower rpm's. For the sake of comparison let's take single cylinders. An RE would be cruising at 80 KMPH at a considerably lower rpm than say any other single cylinder in the Indian Market of the same or lower class cc. One would say it is due to RE's employing pushrod long stroke configuration that makes them cruise at 80 KMPH at relatively lower rpm's than its peers. Ah yes! and the torque delivery dynamics.

On the Royal Enfield's the last gear is 1:1, so basically it doesn't have overdrive.

This is something I'd learnt from TBhp as before I presumed even RE's had similar ratios as other motorcycles.

Agreed but rev matching and downshifting doesn't apply to old RE's while reducing the speed to near 20-30 KMPH even while being in top 4th gear and rolling on from there up to 80-100 KMPH in the same top 4th gear. Many might call this "lugging" the engine but that's what Flat Torque Curve is supposed to do without damaging the engine.

It would be interesting to know RE Himalayan gear ratios.

[ashwinprakas]

Originally Posted by navin_v8

Ah yes! and the torque delivery dynamics.

I'm very much a fan of the way the pushrods put out torque.

An incident I recall was riding my CT100B on the way to WB from OD on the Asian Highway at 100~110kmph speedo indicated speeds obviously fully crouching, my friend was riding ahead on his UCE 500 at about 120~130kmph as per his speedo at a relaxed pace, while mine was going TRRRRRR...RRRRR..RR his was simply going gududududu... due to his being stock exhaust, which was quite obvious since he was at about 5k RPM and I was at about 12K RPM.

Just then I hear a long stroke thumping from behind and it was catching up, but surprisingly without loosing composure... Dug...Dug...Dug, I was dumbfounded thinking how a long stroke can do 100+ kmph without the usual irritating DRRRRRRR...RRR... when running on the unrestricted pipes that was common on older models.

Anyways I couldn't see him in my RVM due to me being fully crouched. He steadily passes me and I see its a CI with a shiny Blue tank with 2 on board, the rider gave me a thumbs up!

But that wasn't it, after that he opened throttle ever so gently and the motorcycle lurched forward but still without loosing its composure and shot past my friends UCE 500 that was far in front of me giving him a thumbs up as well.

I was simply flabbergasted by how a CI and that too one that had to be insanely over-geared managed to do speeds way above 130+kmph effortlessly and overtake a UCE 500 without breaking a sweat.

I have known friends and fellow enthusiasts who've built souped up CI's and AVL's, a notable mention goes to Sanket Sarkar's 535 Build that rev's all the way up to 7000 RPM, there are even some British builds that go up to 10,000RPM.

Here's a snap of Sanket's ride;



But this one CI still stays in memory. Simply awesome it was. Its very sad that I didn't have the presence of mind to signal him to a stop for a chat.

It would be interesting to know RE Himalayan gear ratios.

1st:2.916:1
2nd:1.833:1
3rd:1.428:1
4th:1.173:1
5th:1:1

As per Gearing Commander.

[navin_v8]

Originally Posted by ashwinprakas

I'm very much a fan of the way the pushrods put out torque.

Although my UCE Tbird500 has phenomenal Torque but I am still in awe of the torque delivery put out by my CI's (especially the Pre-70's models). Only regret I have is not being able to buy a CI 500. My inspiration to buy RE Tbird500 came from RE Lightning CI 535(considered to be the father of Tbird series). I came very close to acquiring a Machismo 500 (which by the way is a fantastic bike with an equally stonker of an engine) but couldn't as I wanted funds to build my old CI, eventually settled for a Tbird AVL 350 at a later stage. I can still vouch that riding a UCE500 isn't as satisfying as riding them CI 500's and AVL 500's.

I was simply flabbergasted by how a CI and that too one that had to be insanely over-geared managed to do speeds way above 130+kmph effortlessly and overtake a UCE 500 without breaking a sweat.

I believe the CI in question would be a 500cc as it would be difficult for a 350cc CI to keep up at those speeds unless its engine and fueling is heavily modified/tuned. There are some CI 350's I have seen undergone several mods to make them go fast and yes they do go fast!

I have known friends and fellow enthusiasts who've built souped up CI's and AVL's, a notable mention goes to Sanket Sarkar's 535 Build that rev's all the way up to 7000 RPM, there are even some British builds that go up to 10,000RPM.

Here's a snap of Sanket's ride;

Attachment 1974795

1st:2.916:1
2nd:1.833:1
3rd:1.428:1
4th:1.173:1
5th:1:1

As per Gearing Commander.

Thanks for sharing.

[jomson13]

Nice topic and some very good replies already.
Adding my points into the fray:
I ride a Apache 200, non abs, carb variant, slipper clutch equipped.
I don't think the slipper clutch helps one bit when it comes to smooth shifting gears. For that only rev matching helps. On my bike, if the engine oil is starting to wear out and I don't rev match while downshifting, the gears are pretty hard to slot into each other.

The other point is what many have already mentioned - Stability. You don't want a sudden jerk to be transferred to your suspension at the wrong time, hence its always advisable to match revs to make sure the gear changes are not too jerky.

Lastly, I just love the sound and feel of the whole thing. My bike is tuned slightly lean and the exhaust lets out some pops when I rev match. I just love the sound of that.

[nitro.1000bhp]

Originally Posted by ashwinprakas

I'm very much a fan of the way the pushrods put out torque.......As per Gearing Commander.

The torque delivery is one of the reasons I bought my 500 back from the same guy I sold it to. That locomotive like pull is so addictive. There are no flat spots or sudden bursts of power..just a clean, linear pull without any drama. Mine is a 2005 CI 500 with a light crank. The last of the CI 500s to be sold new. The way this thing picks up rpms is astonishing. It spins up faster than a 350 crank!

I essentially use my bike as a 3-speed. 1st is pretty unnecessary unless you have to start on a steep incline. Else I simply click it upto second from a stand still and it will gracefully waft off. Shift to 4th around 40kph and it will go all the way upto a Speedo indicated 125kph!. It's the perfect bike for city commutes as you can change gears if you feel like but it's not really necessary

[ashwinprakas]

Originally Posted by jomson13

the gears are pretty hard to slot into each other.

That's your engine oil loosing its shear stability, that is ideally when you're supposed to change the engine oil.

At how many km's does this happen?

[rdst_1]

Reading the above few posts have really made me start craving a Bullet 500. Like I said before, we have a 97 CI 350 at home but ever since I moved to the hills I feel it is a bit underpowered. I guess even the 97 CI came with light crank so the heart really craves for a nice really old 'heavy crank' 500, when you read such nice posts about those beasts.

[Ricci]

Originally Posted by navin_v8

From what I know, Overdrive gear is related to any automobile going at a constant/sustained speed(read cruising) at relatively lower rpm's to put less load on the engine compared to lower gears at high rpm's at the same speed.

I tend to agree. Lot of people believe a gear is an overdrive if the ratio is < 1. This is an oversimplification, IMO, and we can get the same overall ratio using ratios of 1, 1< and <1. For example,


Primary reduction : 2.5 <--> 3.00 <--> 2.5
Final reduction----: 3.0 <--> 3.33 <--> 2.5
Top gear ratio--- : 1.0 <--> 0.75 <--> 1.2
Overall top ratio : 7.5 <--> 7.50 <--> 7.5

All of these deliver the same overall ratio, so the road speed will the same regardless of what the top gear itself is 1 or 0.x or 1.x.



Instead, my understanding of what overdrive really is, that a gear ratio that tops out at a speed lesser than the previous , or , in another way, if the vehicle cannot reach peak power RPM in that gear, such as the old gen1 classic Pulsar 150, which would top out before hitting its peak power RPM, but delivered excellent fuel efficiency (60+ reported by several owners then). Thus being "over"driven , geared for more speed than doable with the power available.



i.e, the top speed of the vehicle is achievable in n-1th gear. I believe some of the 6 gear cars are like this, wherein the 5th gear gets the highest speed, say, 210km/h , while 6th tops out at say 190km/h.

[jomson13]

Originally Posted by ashwinprakas

That's your engine oil loosing its shear stability, that is ideally when you're supposed to change the engine oil.

At how many km's does this happen?

It starts acting up around 3000kms, I usually change around 3500 - 4000. currently using motul 7100 10w40