It appears that most modern chainrings have a 10 mm hole with a counter sink to accomidate the bolt head, thus centering the chainring bolt in the hole. What do you do if you are going to install a chainring guard that has a 10mm hole with no counter sink?

I know you can flip the chanring bolt and put the nut on the outside as the nut's OD is 10mm, but what do if you want to keep the bolt on the outside? I see that Campy makes some kind of shoulder bolt, but it seems to long for the project.

I thought of taking an aluminum chainring nut and cutting the width down to just a little over a 1/16 inch thick (or whatever the charing guard width is) and then screwing that onto the chainring, thus making a chainring bolt with a shoulder.

Seems like a lot of work, but I have a jewelers saw and needle files, so doing 5 would not be the end of the world. Just wanted to know if there was an easier way.

Tom

Longer chainring nut? It should be long enough to partially stick into the chainring guard from the backside.

One of the problems I ran into was trying to install a Sugino chainring guard next to the outter chainring. The guard is only like 1/16" thick with a 10mm hole, so it would be nice to have a spacer on the inside and the outside with a small gap in the middle. I supose one could have the bolt stick out a little past the guard, then use a washer to take up the gap, but this is not as clean as having a 8 x 10 washer go over the end of bolt.

Tom

You're putting on a chainguard.

Who cares if it looks clean, its already ugly.

Nicer chainguards will have the counter sink on them
Cyclocross world dot com sells some , though I expect a CF chainguard as they are CNC cut from sheet
may not then I wont matter.. 3 chainrings on one bolt circle bolt sets come with a spacer ,
getting 5 bolts normally used to screw on the granny gear are longer than the bolt that comes with a double chainring bolt set.

if you are running 2 chainguards one replaces the inner chainring. ,
there is a spacer between the outer and the chainguard.

I run a chainguard a 50t ring and a chainminder on my touring triple ,
never miss a shift.