Gearing on the YZ400
Posted November 13, 2000 - 08:04 PM
Posted November 14, 2000 - 03:35 AM
I race hare scrambles on the east coast, and have found that a 14/51 (stk front,two up in rear) combo works great with a 110/100 tire. I broke am countershaft spk last week and switched to 13/49 (stock on rear, one tooth less in front) with a 120/100 tire. This combo is way too low, first gear is useless (unless you like to jump on flat ground). I ride very few mx tracks but I think the 14/51 would be great there as well.
If your going to race more in the woods I would recommend a flywheel weight. I run a 14OZ but would use a lighter one (maby a 10OZ) for the mx track.
Hope this helps,
[This message has been edited by GNCCYZ400 (edited 11-14-2000).]
Posted November 14, 2000 - 06:31 AM
The WR has a lower 1st gear, but after that the YZ gears are taller. You can, of course, change the sprockets. It really depends on what you plan to do with the bike. If it is mainly tight trails then the WR tranny would be the way to go. If it is more motocross then the YZ is the way to go.
Hope this helps.
Posted November 14, 2000 - 06:54 AM
On the 99 wr it has a 1st gear that is 25% lower than the 99YZ, 2nd is approx 11% lower third about the same 4 is approx 5% taller and 5th is 11 % taller. So if you gear down the YZ by 25% to get a comperable 1st gear you will be 36% lower in 5th gear comapred to the 99 WR and this is with a 99. The 00 and 01 are worse off in the woods, putting the WR tranny in a 01 YZ sounds like the best solution if you want a YZ and ride in the woods or want to dual sport it. The parts cost is not too bad but the labor unless you do it yourself is expensive as you must remove the engine from the fram, tear down the top end. split the cases to change the internal gearing and of course build everthing back up and reinstall the engine.
I guess while the shop is doing this you could grease the steering stem bearings and all the rear linkage bearings and detail out the rest of the chassis.
Posted November 14, 2000 - 08:02 AM
Are you saying that gearing down with sprockets will make it a ton slower....I just thought that if you moved 1st down a few mile per hour then the top gear would move down the same and the differance wouldn't be that noticable....I don't need to be able to go 100mph but I don't want to have a slow bike!!!
Posted November 14, 2000 - 11:34 AM
Originally posted by BenjaminPQ:
....I just thought that if you moved 1st down a few mile per hour then the top gear would move down the same and the differance wouldn't be that noticable…
The difference will be the same in the relative sense but not the absolute sense.
For example, if you go from a 14/49 to 14/51 you have “geared down” by around 4% (2/50). So your bike will be going 4% slower than before in each gear.
Because first gear in a WR is so much “shorter” (Clark says 25%) it is not practical to match the low speed grunt by just changing sprockets.
So in answer to your original question it is not possible to change sprockets on a YZ to make it geared like a WR. Changing the gears themselves is the only way.
Posted November 14, 2000 - 01:47 PM
Changing sprockets will only help to crawl easier with less stalling and clutch work. You'll loose some top speed, but will get there quicker if traction allows. You still have to shift more due to ratios being "close", meaning the difference between gears is close and the engine redlines quicker in each gear. So that keeps you at the top or peak HP levels longer. Great for racing, difficult to control for slippery trail work, especially low gear is 25% higher than the WR.
Either buy the YZ, add a flywheight weight and consider changing internal gearing (like clark said not expensive if you do it yourself) if you're considering 75% off-road OR Buy the WR and turn it into a YZ like many of us have (timing, pipe, tank, seat, weight loss,etc). The kickstand, lighting, valving, and 18" rear are factors too.
But I'm a trail rider primarily I've done some MX on the bike and it does great, but I'm not doing doubles or triples, just old guy singles and tabletops.
I rode a 13/49 YZ and hated the gearing in muddy hilly trails. It was stock other than gearing. The WR just chugs along easily if you want or digs in and goes no, you don't have to be in attack mode all the time like on the YZ.
On the other hand, the YZ is more rideable requiring less time and money to be fast than the stock WR. So maybe adding the $80 flywheel weight and making due with sprocket choices is the cheap ticket? Then doing the real gearing change down the road will give you a scweet do-it-all light bike. But think loads of cash if you want lighting on the YZ
Posted November 14, 2000 - 07:00 PM
The suspention is the main cause for me wanting the yz over the wr the weight is also a factor. I just want a motocross bike that is good in the woods!!!
Posted November 14, 2000 - 07:55 PM
close ratio rules, huge
Posted November 15, 2000 - 02:22 PM
over in england you have to run a YZ if you want to win a woods enduro. the gearing? they just don't listen to the engine.