Yamaha TRX850 Enthusiasts Forum

Can anyone confirm please which way the front sprocket goes, mine has a boss machined on one side does this face the engine or outwards?

I'm away from my bike at the moment but the usual rule of thumb is that the side with the size (no. of teeth) stamped on it faces outwards.

Hi Simon

Looking at your bike, you have a yzf rear end fitted.

The std front sprocket is flat, so i would say you have an offset front sprocket fitted to align it with the yzf rear sprocket.

If this is the case, the boss faces the gear box.


Cheers, Andy.

Std trx sprocket has from memory a 3mm raised offset on both sides . A quick check on a sprocket site will give you the exact offset. Scrolled through for a few hrs when tracking down a 520 set up.
The 520 r6 front sprocket I'm using has the same trx offset on the side facing the engine and flat on the other side facing outwards.

It's usually flat side facing outwards on most bikes - why would you need a raised face/boss if it wasn't to correct offset?

Cheers guys I was having a problem with the rear wheel binding, I loosened off the rear wheel spindle and it improved then started worrying that I had put the sprocket onn wrong - I was pretty tired and it had been a long day. I looked into it again last night and it turned out the rear caliper was seized on the disc so problem solved.