tmnguuyen 

Hello BFers,

I'm currently working on a Raleigh Richmond. The bike comes with a single chain ring Thun crank set. Please see photos below. The ring has tapped holes for a chain guard ring. There are also untapped holes. I'm curious if these are for the mounting the second ring. If so, anyone has a source for a smaller ring and mounting bolts? The ring has a 3 hole pattern, i measured the distance between 2 adjacent holes = 100mm per Sheldon's cheat sheet the BCD is 116mm. Thanks @juvela to tell me to go do more digging....
I have a set of TA i may throw on there but this crank set is interesting and i believe it is original to the bike.

Thanks

juvela

-----

one thing which would help readers to help you would be to give a bolt circle diameter for the holes you believe to be for a second chainwheel


-----

oneclick 

If they are for another ring, you may be lucky; the existing ring appeares to be dished away from the outer side, and it may be that a ring could be bolted directly to it and have sufficient clearance for the chain.

If not you'll need spacers.

tmnguuyen 

I was thinking the same thing. It appears that the outer ring was deleted to make is a single ring set up. This however may prove to be a lost cause in looking for the extra ring and mounting HW. I may just put the ring guard back on and ride as is or put on the TA set for extra gears and climb.

Thanks