XR chain guide mod

With the the OEM chain guide and my 5" Excel rim ,I had some clearance problems when I adjusted my chain to the second part of the chain adjustment range .I toke an old XR600 guide (they are all the same on the XR's) and did some cutting an adding a 32mm DRC chain roller on bearings.So no probs anymore: less (power) robbing/ drag and great clearance for the rim and full chain adjustment range. In Europe, Monobike racers remove the guide completely but I take my SM off-road now and than ,so I did something different. :ride: This mod should be good for chain life too. It works great on my Honda XR680R supermotard and it should work for light off-road/dual sport use also with the stock wheel.

Stock versus modded





DRC 32mm chain wheel


Before mounting. You need : chain wheel on bearings, OEM Honda bolt and nut, 2 washers ...


Voila. No drag,great clearance for the 5" rim. Should work great with 40 to 45 rear sprocket.

Smart thinking! Is your swingarm black?

yep.

http://www.xr650rforum.com/the-mod-squad-f2/xr680-build-rebuild-t512.htm

cool idea but, I was thinking, wouldn't be better to leave the front location to mount the wheel?
I mean, in your mod you did leave the rear location (facing forwards) to mount the wheel, the one nearer to the rear sprocket, I think maybe it's better to mount the wheel in the other position, looking at others off road bikes.

what do you think about?

If you place the roller in the front of the guide (left bolt) ,you still have the problem of the 5" rim touching it. And destroy a nice Excel rim....

so this mod is useful only for motard configuration? I mean big rim and small rear sprocket?
But If I could do it for off wheels 18-21?

i only flexed a little piece of the chainguide on the back so it can not touch the rim, onfront it looks like a normal chainguide and it works fine but with the chainroller is nice to and im gonna make one like that in the future when i need a new one.

@xrmanu, I tried to do that, but chain flowing on the roller is very noise! Too annoying...

what about yours?

What sprocket size are you running? Is the roller free to move?

rear sprocket is 44 or 45 teeth, I think noise is caused by the harder plastic of the roller (that can move easily), while the original is a little smoother...
Are you saying that yours don't make noise? Is your roller smooth?

I don't have any noise with a 40t sprocket... from 0 to 190 km/h....

I used a roller on bearings and have put washers between the roller and the slider to have free movement.

xrmanu nice mod, I will be doing the sm mod and I wil need this step, do you have the pics with some explanation how too do it, by the way post some pics of your sm please! could you also send your spec I want to have all the info I need to decide which way to go.

Thanks,

BM

I think the first pics speak for them self.

My bike: http://www.xr650rforum.com/t512-xr680-build-rebuild?highlight=xr680