New 450 EXC Sprocket Changes

New bike, wore my butt out this weekend (litarally with that comfy as a 2x4 seat...)

Very Fast and light. Felt great and controlled for the speeds I was going EXCEPT uphill in the woods on loose rutted out clay. It is geared to tall for me (SE ky woods - goat paths). stalled about 3 times with one get off (didnt try that hill again - swore I would get new sprockets first). Im gonna wear out 1 and 2 gears and never use 3,4,5,6 with stock sprockets. Also a bit too fast down hill - have to steer to avoid those ruts you know...

Right now its 14/50. anybody make changes yet? what did you go to and/or recommend?

A 13t up front will get you close. It will wear out more often so keep an eye on it and replace it when the teeth start to hook. It will also wear out the swingarm chain buffer faster so keep a spare of that around, too.

Most folks who ride in the tight woods go with 13:52. That's what I used on my 01 400E. I went 13:51 on my 03 450E and that's okay, too. No chain mods were needed for any of the gearing I've used. The stock gearing is way too high for woods work, though.

We gear most all of our 400/450s at 13/52.

So with 13/52 will the stock chain fit? or should I buy one of those too. If I need a new chain I might try 13/54 at first (this is after researching many posts on this subject...). get some tractor-like low end. If no new chain 13/52 sounds like the ticket.

As I said in my post above, no chain mods were needed for 13:51 or 13:52.

Thanks, just wanted to clarify. Time to shop for sprockets.

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Jeb's right about wearing out that 13t fast - keep on eye on chain tension too (not too tight - not too loose). I have had my 2002 520exc for ten months. I put the 13t on it right after break-in. Yesterday, I was out riding some woods - racing tree to tree - and heard a lot of chain slapping and then a loss of power. My countershaft sprocket had little nibs where there were once sharp teeth. And the protector that wraps around the swing arm has a big hole near the countershaft sproket. It looks like I have some work to do before racing this weekend :)

Everyone with a RFS I know has steered clear of 13 tooth countershaft sprockets. Too tight of a radius to clear the swing arm, and binds the chain. 14/50 on my 520 is ideal, I'd imagine 14/52(54 if you really need granny gear) would work well on the 400. The 520 came with 14/48, 6th gear was good for 105+!

I'm with Kieth. I don't understand this insistence with going down in the front. Can it be worth the hassle of looking after the swingarm and countershaft when we could just go up 2-3 teeth in the rear?


FWIW Guys,

I went with the 13/52 combination after the first ride on my 400. That was October of 2000. The bike now has 3,350 miles of trail riding on it with no abnormal, or noticeable, wear on the front sprocket, swing arm slider, or chain.

The rear Aluminum sprocket is starting to get a slight "hook" to the teeth on it so I'll be replacing the sprockets and chain this winter. The only real wear item I've experienced is on the retaining clip on the master link. I've replaced it once since it looked a little thin where it slides against the stock rear chain guide.

All-in-All, I haven't experienced any of the problems that people are speaking of regarding the 13 tooth front sprocket. I'm even contemplating running a 13/54 for the next gear change to make it even more of a tractor in the tight stuff!! :) It'll still do 78 mph with a 13/54 combination, which is plenty-o-speed for my typical riding.


Notice the two guys using the 14t are from Cali and Nevada where the riding is more open, generally. For the tight woods, the 13t is pretty much mandatory and every RFS owner I know runs it. To get the same ratio as a 13:52 with just a rear sprocket change would mean you'd have to use a 56 rear. I doubt anyone makes one that big and, even if they did, you'd have problems with chain guides and have more chance of bending it. Plus you'd need a new longer chain.

I only go through one buffer a year but I do tend to go through 3 or so 13t CS sprockets. Still, it's worth it to get it geared correctly for the riding I do.

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