Sorry about the vagueness ahead!
I have dug out a set of Stronglight cranks. No markings. 110mm BCD outer/inner with usual 74 BCD granny ring. Went to bolt a non original inner ring on to find that a) it would be flat against the crank with no spacer and b) the bolts are smaller than normal . Possibly the original ring would have had a built in spacer as the area around the hole is very limited so any spacer will be narrow. Any guesses, based on my feeble description, as to what bolts are needed?
Stronglight inner chain ring bolts.
Re: Stronglight inner chain ring bolts.
I have seen some chainsets (SR Sakae springs to mind) which use bolts which look like this
together with spacers to secure the inner chainring of a triple. The spacers that are meant to go with the bolts are fairly straightforward, but the bolts are rather unusual. IIRC they are usually threaded M6 x1.
If you have clearance to the chainstay, and access to a lathe, it ought to be possible to make shouldered spacers (which locate and support the chainring properly) and then to use more standard M6 bolts of some kind instead of the special ones. Conveniently enough, some standard sized M6 washers have the correct OD to fit into typical chainring counterbores.
I have also seen chainrings at standard BCDs but with smaller holes in them, which again use weird bolts and spacers.
First step is to (carefully) try an M6x1 bolt in the threaded holes.
cheers
together with spacers to secure the inner chainring of a triple. The spacers that are meant to go with the bolts are fairly straightforward, but the bolts are rather unusual. IIRC they are usually threaded M6 x1.
If you have clearance to the chainstay, and access to a lathe, it ought to be possible to make shouldered spacers (which locate and support the chainring properly) and then to use more standard M6 bolts of some kind instead of the special ones. Conveniently enough, some standard sized M6 washers have the correct OD to fit into typical chainring counterbores.
I have also seen chainrings at standard BCDs but with smaller holes in them, which again use weird bolts and spacers.
First step is to (carefully) try an M6x1 bolt in the threaded holes.
cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
Re: Stronglight inner chain ring bolts.
Oops. yep m6 thread.
Re: Stronglight inner chain ring bolts.
If you go down the M6 bolt route and need to shim the M6 bolt up to the chain ring bolt hole diameter, conveniently the M6 washers that come on (most but not all) V brake pad fittings are a nice fit inside a chain ring bolt hole. You will still need some spacer or other between the ring and the crank arm of course.
If you don't use V brake pads, I'd ask a friend/friendly local bike shop to put some worn pads (with fittings) aside for you. In the recent wet weather they'll be replacing loads of worn out pads.
If desperate I could post you some.
If space is tight with the chain stay, a standard bolt head (10 mm spanner) will have a lower profile (probably).
I had a similar (new I think) chain set (quite a few years ago now), I somehow ended up with a chain set with a duff bolt (the bolt had missed the machine that stamped out the allen key hole). Despite working in a decent bike shop, no spares were to be found. I managed to get a replacement only by asking at the Stronglight stand at a trade show, and was allowed 1 bolt out of the bag to take home!
If you don't use V brake pads, I'd ask a friend/friendly local bike shop to put some worn pads (with fittings) aside for you. In the recent wet weather they'll be replacing loads of worn out pads.
If desperate I could post you some.
If space is tight with the chain stay, a standard bolt head (10 mm spanner) will have a lower profile (probably).
I had a similar (new I think) chain set (quite a few years ago now), I somehow ended up with a chain set with a duff bolt (the bolt had missed the machine that stamped out the allen key hole). Despite working in a decent bike shop, no spares were to be found. I managed to get a replacement only by asking at the Stronglight stand at a trade show, and was allowed 1 bolt out of the bag to take home!
Re: Stronglight inner chain ring bolts.
Got millions of those washers. Knew they would be useful one day. Ta.
Re: Stronglight inner chain ring bolts.
Just found that the inner ring I wanted to fit, being a normal triple granny has smaller holes than the outer rings. The above washers fit nicely in those.
I did find that the conical wager/spacer from the brake blocks settles in nicely though. Not quite thick enough though. Hmm
I did find that the conical wager/spacer from the brake blocks settles in nicely though. Not quite thick enough though. Hmm