While renewing the chain on my bike I fitted a new rear sprocket to the sprocket carrier and torqued up the six nuts which secure the sprocket to the carrier/hub assembly - all of the nuts were tightened to the correct torque and won’t turn anymore - apart from one nut which keeps turning - or to be more precise it is the bolt which the nut is threaded onto which is turning.
The bolt that is turning is (like the other five bolts) built into the sprocket carrier and there is no obvious way of extracting the offending bolt or fixing the problem.
Is this something that can be fixed or will I have to source a replacement sprocket carrier.
try chemical metal to bond the stud in place …extract stud place chem metal in and rethread stud in allow to cure and tighten … or possible helicoil … but may be easier to get a new /second carrier than helicoil …
Thaks for the replies guys - here is a pic of the underside of the carrier.
looking at the constructon it doesnt look like a captive bolt - I’m guessing the thread is gone as you say which would require a helicoil repair.
However - i’ve just seen one on ebay for £12 + £7 postage so I guess that’s probably the best route - assuming it is in A1 condition.
They are all torqued up properly - apart from this last one which got to the torque bite point and then kept turning - so it is on safely - but when I come to change the sprocket in the future I am anticipating that I’m not going to be able to get the sprocket off the carrier - becuase the bolt is not fixed anymore and is turning independently of the carrier.
So the simplest solution seems to be sourcing a new carrier and have it ready for the next chain/sprockets replacement.
Go for the one on fleabay if it’s in good condition.
They look like those cwap “bolts” that have a round mushroom heads and splined shanks. It’s common for the steel bolts to strip the splines in the alloy so they just spin in the hole.
There are decent fixes but they are a pain in the arris without either a decent press drill or a very steady hand and good eye.
Yes Oldguy - it will be easier and cheaper to get one off ebay than do a helicoil repair - there are a couple of reputable sellers who state that the part is in perfect condition.
Yes Choprocker - the stud is turning in the carrier - so the internal thread/ribbing has gone.
Plural is operative here! I have three of the f*ckers - which accounts for so many posts!
I bought all my bikes old and cheap - the problems I encounter are usually due to a lack of maintenance by the previous owners - the bane of my life has been rusted studs and bolts - If I ever bought a bike new none of this stuff would happen because I would have everything copper greased from the off.
p.s. The problem sprocket bolt was tightened with a torque wrench to the manuals spec so it was a failure of the component rather than an any error on my part.
Sticking a bolt through the hole is so blindingly obvious I missed it.
Note to self: Must stop thinking like an engineer.
(The old fashioned fix was to drill a hole through the joint between the “stud” and the casting and tap in a dowel to lock one to the other. Sticking a bolt through, even if you have to drill/ream out the hole to get a snug fit, is so much easier.)
Thanks Desmo man - would love to visit your place some time as I’m hearing such good stuff about you.
Yes Oldguy - really like Choprockers very neat solution.
Jetstream - the bike is sound - it’s just irritating small problems due to age - it’s also totally environmentally unsound to keep buying new machinery just because a bike is getting a bit long in the tooth and needs a bit of extra attention - years ago people learnt mechanical skills because they had to make their bikes and cars last and didn’t replace them as regularly as we are used to doing - although i reckon our new age of austerity is gonna bring the old times back
