Rear Chain Guide - TM DesignWorks

I tried one and the one I tried does not fit the WR250R. - I called and spoke to these guys because I was interested in trying out this rear chain guide. The guy I spoke to thought I should probably try the guide for a YZ/WR 250-450F. I tried it out and nothing lines up. I doubt they will be making one since there would probably not be much of a demand.

http://www.tmdesignworks.com/index.php?main_page=index&cPath=3_4_11

My stock chain guide does not currently need replacing. Im just curious my options for replacing it and decided to try something. Does anyone know of something else to try?

The part numbers for the stock chain guide parts are not used on any other Yamaha motorcycle sold in the USA as far as I know, other than probably the WR-250X.
So, that usually means the chances are unlikely one made for another Yamaha model will fit.
I can't say that with 100% certainty, though, and if I had to guess, your best chances are probably one from the oldest Yamaha YZs that TM will make one for.

I recently considered replacing the stock chain guide on my 2009 WR-250F with one of the TM Designworks ones, but I decided against it when I realized how much physically larger it was.
I believe that's required since the TM one is basically a few chunks of (relatively) soft chain guide material screwed together, and it needs the added bulk to be strong enough.

Kinda' ironic because for years, back through the 1980s, a stock Yamaha chain guide was simply a solid, one-piece block of chain guide material bolted to the swingarm.

the nice thing about the stock chain guide on our bikes is if you break the outer shell, you can just replace it and not the inner piece, so cheaper than replacing the entire guide (assuming the inner piece is still ok). I think the outer shell is around $25 maybe .. vs $60 or so for replacing the one piece TM guide.