Horizons Unlimited - The HUBB

Horizons Unlimited - The HUBB (https://www.horizonsunlimited.com/hubb/)
-   Yamaha Tech (https://www.horizonsunlimited.com/hubb/yamaha-tech/)
-   -   Gearing change. Same bike – changed characteristic. (https://www.horizonsunlimited.com/hubb/yamaha-tech/gearing-change-same-bike-changed-46635)

G600 21 Nov 2009 21:05

Gearing change. Same bike – changed characteristic.
 
Hi all.

Little info for those considering some gearing changes…

The bike is a 2005 TT600RE. The stock front sprocket is 15t.I got my 14t front sprocket from wemoto yesterday and installed it this morning. Then I went for a ride, 40 Km offroad/trails, 70Km road, 20 Km around town.

The sprocket is made by “Techcorps”. It looks like a quality part, I like how they let the splines run the whole width of the sprocket, and not only 2/3 of the way like on the stock Yamaha (see pic).

The sprocket swap was straight forward. I did not need to shorten the chain, I had enough adjustment left.

General:
The bike feels more responsive, the difference is very noticeable. With the stock gearing the bike felt a little lazy, but now it will pull better out of turns and feel more “awake”. Gearing changes have great impact on how smaller capacity bikes feel, but I did not expect this big thumper to react this much to one tooth change on the front sprocket.

Offroad:
Big improvement. The first gear is now OK (but a little high), and the second nearer to it. Much easier to find the right gear in the rough.

Dirtroads/trails:
Big improvement. The bike is now plain more fun. It will pull better out of corners. Easier to power slide. More responsive.

Road:
The sweet spot in fifth gear is now around 90 KM/H, perfect IMHO. I was not happy with the stock gearing on the road, fifth was often to high ( no lugging - fifth gear problem) so I was changing between fifth and fourth a lot (uphill, downhill, wind, exc) . I hardly ever ride the bike over 100 KM/H for any length of time due to the upright sitting position and the lack of windshield. For people riding over 100 KM/H for long periods of time it’s better not to lower the gearing. I did run the bike for a short period at 110KM/H and it was OK I guess, but the RPM’s felt a little high.

Wheelies:
Big improvement. I have been pulling wheelies in second gear on this bike, I am not good enough to use first gear. To lift the front, with the stock gearing, I needed to move backwards on the bike, hit the front brake hard to compress the forks and then, when the forks rebounded, clutch and throttle aggressively. Timing was everything. Hard to do. Now the procedure is the same, but *MUCH* easier.

So for me, this change was 100% positive. Bigger difference than I expected for sure. But for someone that mainly rides on the road at higher speeds… not a good idea.


http://i697.photobucket.com/albums/v...t_sprocket.jpg

oldbmw 21 Nov 2009 22:59

Quote:

Originally Posted by G600 (Post 264970)
Hi all.

Road:
The sweet spot in fifth gear is now around 90 KM/H, perfect IMHO. I was not happy with the stock gearing on the road, fifth was often to high ( no lugging - fifth gear problem) so I was changing between fifth and fourth a lot (uphill, downhill, wind, exc) . I hardly ever ride the bike over 100 KM/H for any length of time due to the upright sitting position and the lack of windshield. For people riding over 100 KM/H for long periods of time it’s better not to lower the gearing. I did run the bike for a short period at 110KM/H and it was OK I guess, but the RPM’s felt a little high.

The Enfield I bough last June has a one tooth higher gearing gearbox sprocket. I am experiencing all the downsides that you describe. I already have an 18 tooth sprocket to replace the 19 one, and am getting together the special tools needed to get at the sprocket. I hope my bike will be just as responsive as yours. These bikes should really be able to roll in top gear all day, without frequent gear changes.
It probably wont affect fuel consumption either, as although the engine might turn a few times more for any given distance, it will need less throttle opening to do it.

Panzer 22 Nov 2009 00:16

Nice review thanks. I think I will be taking that path when I change my C&S, most roads I ride on i'm doing 40-50 mph and constantly changing gear so as not to labour the 5th gear, its a bit of a drag.

Pigford 22 Nov 2009 09:54

Thats interesting, cheers for the info G600 :thumbup1:

What about the prospect of fast wear with a part worn chain on the new sprox?

I didn't realise the std Yam front sprox had a part spline :thumbdown:

Think I'll cheat and wait until me chain is getting towards then end of adjustment the go for a 2/3 teeth bigger rear sprox :clap:

my headlight (more like parking light:() keeps blowing. See new thread.

G600 22 Nov 2009 10:50

Quote:

Originally Posted by Pigford (Post 265007)
I didn't realise the std Yam front sprox had a part spline :thumbdown:


Pigford, please don’t get me wrong, the std Yamaha sprocket is a top-notch quality part. I have never heard anything bad about stock Yamaha sprockets. I would not hesitate to use one again, even if I find the design a little strange.



Quote:

What about the prospect of fast wear with a part worn chain on the new sprox?
This is true I’m sure. You will get the best durability by always replacing everything as a set. But I have found after 30 years of messing with bikes that the biggest issue is with the chain. If the sprockets are only lightly worn you can just replace the chain. If the chain is worn/stretched it will eat up the sprockets. I have had two rear wheels (different tires), on several bikes, and changed back and forth without problems. On other bikes I have had different size front sprockets and changed back and forth, without problems. The key here is to always have a good chain, unless the sprockets are junk anyway.

Sorry to hear about the headlight problem, I will keep an eye on that thread.

BlackDogZulu 22 Nov 2009 17:36

Just to back you up, I used to have an XT660R, and I went down to 14T on the front with that. It transformed the bike in the way you describe, perhaps even more. I think the 660 is geared way too high to get around noise/emissions regs, and the smaller sprocket made it feel 'right'. You don't need an 80mph cruising speed on a trailbike. The smaller sprocket made it much more lively, and I didn't miss the extra top end at all.

The only issue was that it knocked the speedo readings out, but your bike won't be affected. There is a workaround with the electronic speedo, but I just lived with it.

zigzag 22 Nov 2009 21:36

hi there my 1985 43f had 1 tooth down on the front sprocket when i bought it 7000 miles ago . i changed the chain/sprockets about 6000 miles ago ,again with 1 tooth down on the front, the gearing seems spot on . i think if i had standed gearing i would be constantly changing between 4th/ 5th . also to pull 5th cleanly i would have to be going like the clappers. so this gearing get my thumbs up , also this must give 5th gear a fighting chance :thumbup1: zigzag

Steve Pickford 23 Nov 2009 10:07

There's another benefit of lower gearing re: trailriding, it limits the ability of the bike to run away from you on steep descents i.e. even in first, the higher first gear can allow the bike to pick up more speed than you'd like, leading to increased brake application and brake wear which in turn can lead to overheating the brake fluid and loosing the brake entirely until it cools down.

If you've ever "smoked" a rear caliper on a big trail bike when descending a steep slope, you'll know what I mean.

I've lowered the gearing on both my 400EXC and 950SE, the minor drop in fuel economy is outweighed by the increased tractability, the 3rd gear wheelies @ 70mph are an added bonus. :thumbup1:

G600 23 Nov 2009 13:03

Guys, thanks for the info.


Quote:

Originally Posted by Steve Pickford (Post 265126)
the 3rd gear wheelies @ 70mph are an added bonus. :thumbup1:



Cr*p.. :eek3::eek3::eek3::eek3::eek3: not on the 400 I’m sure????

Steve Pickford 23 Nov 2009 13:54

Quote:

Originally Posted by G600 (Post 265142)
Guys, thanks for the info.

Cr*p.. :eek3::eek3::eek3::eek3::eek3: not on the 400 I’m sure????

On the 950, the 400's revving too high @ 65mph in 3rd although it's easy to get the front up in 3rd at 35-40mph if you shift you weight back a little.

With the 950, you don't have to be so hard on the clutch or throttle to wheelie in 3rd with the slightly lowered gearing (16t front, stock rear), making it more controllable for a wheelie n00b like myself.


All times are GMT +1. The time now is 10:58.


vB.Sponsors