Single Speed chain, bashguard question.
 

Ok so my SS MTB build is done and I took it for a test ride. Right off the bat something doesn't sound right and it looks like my chain jumps a little every so often. Took me a few seconds but the issue is that the SRAM link (I have a SRAM single speed chain and a Bontrager SS Crank with bashguard) is hitting the bashguard every time it come around. This SRAM link isn't the one like the 8 and 9 speed chains have it has both pins on one side and a plate on the other. So anyway this link is clearly wider than the rest of the chain and is hitting the bash guard in a bad way. Should I just ditch this link? This chain seems to have old school pins that could be reused (again unlike a 8/9 speed chain), is that correct? If so I think I will just take the link out and put in one of the extras. Also my chain line isn't perfect and is part of the problem here as well, I believe I have the BB shimmed so that it is centered but the chain wheel needs to come out more, is the proper fix a wider BB (I have the 113mm that the crank specifies in it's lit)? Or shimming of either the BB or the crank arm?

Thanks for any help.

The SRAM SS chain is 1/8", so it's going to rub some when running a bashguard. You can put the chain together without the power link to stop the skipping.

You can try moving the spacers around on your hub, if you've got the room. It looks like you've got a Shimano freewheel. If that's so, be careful, because those splines will chew your frame up if they rub.

Well I did what you suggested before you posted. I guess that is the best way to deal with it. For reference I have a Surly rear hub with an ACS freewheel.

The BB instructions said to have the 2.5mm shim installed if I have a 68mm BB (which I do) and then to shim as needed. I got another 2mm shim and the LBS was reluctant to sell me any more asking if I knew what I was doing (to be honest this was the first time I have done a SS and adjusted a BB for chain line so no) and asking if I had measured the BB once installed. With the added 2mm spacer (so the 2mm plus the 2.5mm that came with it) I believe the BB is centered in the frame (as best I can measure). I share the mechanic's concern to an extent and wonder (other than BB thread engagement to the frame which was his main concern) what the implications of shiming it over would be. Maybe I will try another 2mm and see what happens.

Thanks and anyone with any more BB shiming comments would be great.

i got a radical idea for ya... ditch your bashguard.... i been riding without one for a year hit my fair share of rocks and logs with the ring and it is just fine!

someone gave me the tip when i was originally building my bike... the logic that swayed me was this: most BMXers don't use bashguards and they seem to be able to brutally hit ***** all the time with no ill affects.

you can buy bmx chainring bolts so it'll fit.

and if you do it, you'll save half a pound, and you'll probably never go back to needing one....

hell, you could probably even sell your bashguard to someone else who "needs" it.

Yea I was thinking about that. Might just do it.

Why don't you just move the bash guard out a couple millimeters? And forget shelling out more than you should for shims down at the LBS. You can probably find some washers that will do for pennies down at the LHS (local hardware store). The chainring bolts should be alright as long as you don't need to move it a whole lot.

I really enjoy being able to break my chain by hand in a few seconds. It makes cleaning the bike too convenient to give up the power link.

DanO