YZ 450 Gearing

Is it possible to add gears to a '04 YZ 450?

If you mean, can you make it a 5 speed, yes, but it isn't cheap.

You can drop in a COMPLETE '03/'04 WR trans (both shafts, shift forks, drum, all gears: $750), or, you can do some machine work and use the complete '02 YZ426 trans.

Thanks! I guess I will stick with the 4 speed. Not that I can use all the power the bike has got now.

One of the things people overlook about the 4 speed is that it isn't only short one gear, it's also a wider ratio box, so it actually covers almost the same range as most 5 speeds. When people ask me if I miss having fifth in the desert, I usually say that I used to miss having sixth, too.

The WR box would make a little better play or desert bike out of it, though. I geared mine 2 teeth higher than OEM (by going to a 15/49 from a 14/48). That gives me a low gear almost identical to a YZ426, and about ten percent less speed in 4th than a 426 has in 5th at any engine speed. On paper (not taking tire slippage, etc., into account), it runs 81 mph at 10,000, and 93 at the rev limit.

The WR would give you a lower low, about the same second, third and fourth, with a big 5th on top. Might be worth $700 to do one day. :cry:

I believe there is a secret formula to make it a 5 speed without machining. If you just drop WR gears in it you may as well buy a WR.

'Don't know why you say that. You would gain very little weight in the process, the engine power would not change, nor would the suspension and handling.

I don't think I would want the ratio spacing any closer than it is now, and it would be if the 426 box were used. Supermoto would obviously be a different situation, of course, but I'd be fine if the gear spacing on the 4 speed was wider even than it is. A little.

Low gear in a YZ 450 is nearly worthless now, as it is a little tall for trail riding the way mine is set up, and way too low for the track in most cases. My only doubt would be whether the slightly narrower gears can take the extra juice.

I put the WR gear setup in my yz :cry: I only trail ride The WR gear would not work very well MX ing 1st is to low and 5 is to high :cry:

Thanks everybody for the input!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now