Gearing on the YZ400

Is it possable to just change the sprockets on the yz400 to make it geared lower like the WR400? I would rather have the YZ because of power and weight but I do tight woods riding along with motocross so I want it geared low.

Benjamin,

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,

Jeff

------------------

'98 YZ400F

'01 YZ250F

'98 CBR600F3

[This message has been edited by GNCCYZ400 (edited 11-14-2000).]

I have been trying to deciede (sp?) between the YZ and the WR. I talked with my local service shop and they told me you can swap tranny's between the two bikes.

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.

Rod

The WR has a wide ratio transmission and the YZ a close ratio. The 00 and 01 426 are geared higher in 1st and 2nd gear than the 98 and 99 YZ's. If you gear down the YZ to make it usable in the woods especialy if its a 00 or 01 then the top end is very limited probably 55 to 62 max so use as a dual sport is basically useless.

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.

Clark

Thanks for the replies

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!!!

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.

The YZ just doesn't feel like a good woods bike to me. Gearing is way too tall and power hits too hard in slippery conditions (damn it's been wet this year!)

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

What is lightning?

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!!!

My feelings toward the yz/woods bike thing are biased. Due to the fact I ride my yz in the woods and love it! I am sure some flywheel weight would due some good, but as far as the gearing goes you learn to adapt. I run stock gearing and found it to work great given the chance. I tried the 13t counter (too low) 52t rear(very good), and stock gearing (just right). I have adapted to slipping the clutch when the going gets real slow. I guess I have always liked close ratio gear boxes and am happy with the yz.

close ratio rules, huge

check clarks figures.. the real difference would be to change 1st & 2nd. the money side i can't say.

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.

Taffy

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