Do you HAVE to use chainring bolts

buddy_club

Hi, building up an old bike as SS- bought a new crankset for it cheap from decathlon (which although advertised as their own has SR Suntour stamped into them) - and as it is a triple only need one ring. The chainring bolts on this crankset actually thread into the middle ring, i have some standard bolts that fit through and tighten up nicely enough, and was wondering if it will be okay using these? I cant see any reason why not?

The Rookie

Common on cheaper cranksets, and the bolt is usually the same thread as a male chainring bolt with a plain section the size of the female for the outer ring and spider location. Your bolts won't have the shoulder though, and ideally you want an SS specific ring anyway. So it will work, but it won't be ideal.

bikaholic

No, you don't have to use chainring bolts. Many other types of bolts will work including hex, slotted and socket button bolts will work provided there is sufficient clearance.

If using in combination with a hex nut then it's wise to add a serrated or a spring washer underneath in order to reduce harmonic vibration loosening the nut and bolt.

If the middle chainring has threaded holes and acts like a carrier for the smaller inner chainring (held on with rivets) then use the bolts that came with the crankset.

If you have an angle grinder and can use it then you can do some mods:

1. If you are definitely not going to use the outer chainring then grind down the teeth and the shifting ramps and convert it into a trouser/bash guard;

2. If the crankset uses the standard chainring bolt/sleeve nut combination then you can shorten the sleeve nuts by carefully grinding them down - use the outer ring to hold the nuts securely in place whilst you grind them (ie clamp the outer ring onto the edge of a bench/table/bit of wood etc with the nuts inserted through the holes, although, I just put it onto the ground and hold it still with my foot).

buddy_club

I only need to use the one ring, the other two (middle and granny) i have removed.
I want to use the big ring in the middle ring position, but the bolts that came with the crankset are not standard chainring bolts - they dont have a female part, so they just thread into the middle ring. I have the ring fitted with some standard bolts i found in the shed. Will just use it as is for a while and try and pic up some proper bolts and some point in the future.

The Rookie

As they won't fit the hole size and locate the ring properly, I wouldn't, not when the proper bolts can be had pretty cheap.