oj.

would i be able to use a nut a bolt for my single-speed chainring rather than proper chainring bolts. the reason i'm asking this is because a need to space my chainring in a few mm and it would be easier for me just to buy some nuts, bolts and washers.

sch

It would work more or less, need a pretty short bolt and a hex head (either hex or allen socket) is easier to deal with than
phillips or slot. About 3/8-1/2" long bolt depending on whether the head/nut/washers fit in the recesses or not.
Chain wheel fixing bolts fit the holes pretty snugly, regular bolts would not so you might get some slippage until the
chain wheel butts up against the bolt threads. A true fixie might result in a back and forth movement of the chain
ring because of this as you torque in two directions. A FW single speed would just move once.

Eric S.

I suppose you could make it work, but I'd suggest purchasing TruVativ chainring bolts. Both ends have hex sockets and they come with spacers.

SquidPuppet

Why not just get a narrower bottom bracket?

fietsbob

OK it's easier, then Go Do It .

I design solutions looking at the bins in the IronMonger's store inventory.

corrado33

Should work fine, it'll be ugly, but it'll work.

OOOOHhh I like those. I like those a lot. I hate dealing with stuck chainring bolts. But then again, it's not like they'd ever be rusted stuck on my bikes so perhaps not as useful as I think?

Eric S.

Once I realized a SRAM Rival crank I bought a few years ago had these 5mm/6mm chain ring bolts, I put them on all my bikes. I toy with gearing and give chain rings a thorough cleaning from time to time and these make life easier.

Moe Zhoost

Or if you need to space the ring outward, you could add some spacers to the BB. If you need to go inward, try mounting the ring on the inside of the crank. Your plan would result in a functional system, but I would bet that you would have a bit of slop that would manifest itself as an irritating click.

FBinNY 

Maybe, or no.

I depends on the crank arms and rings. Some arms and rings have the ring supported on machined shoulders in the crank spider with the bolts providing only the retention and driving torque. However, that's a bit of extra work in production and many makers have eliminated the shoulders.

Without the locating shoulder, the ring depends on the OD of the outer bolt to locate the hole aligned with those in the crank arm, so it's properly concentric to the center. Poor concentricity causes 2 problems.

1- change in chain tension as the crank rotates. Some is normal, but more is worse.
2- allows the ring to shift u8nder load causing chronic loosening of the bolts, (and changing concentricity).

So, given what you have invested so far, the smart play is to shell out for chainring bolts that can reach past your spacers and position the ring correctly. Or, of you're only talking of 1-2mm, don't bother and live with the slight chainline error which is the lesser of evils.

oj.

i have measured the id of the chainring and the crank and i got 9.5mm which roughly equates to 3/8 of an inch. i can buy 3/8 bolts and i think that it should be close enough so there is no movement. also i would normally consider using bottom bracket spacer or buying a smaller bottom bracket as other have suggested but I am using a press fit bottom bracket that can't be any smaller so my only option is to move my sprocket inwards.

LesterOfPuppets

How much in does it have to go?

Actual spacers aren't all that expensive
https://www.sjscycles.co.uk/chainset...ers-pack-of-5/

If you need to shift it in more than a mm or two, you might have to spring for a set of bolts for a double
https://www.sjscycles.co.uk/chainset...ainring-bolts/

oj.

it has to move about 3-4mm

oj.

i can get everything i need for £7

LesterOfPuppets

If you can get bolts that won't interfere with your chainstays and think a setup like this is worth saving a couple of pounds, I reckon you might as well go for it.

oj.

cheers