squeaky chain set

[ferrit worrier]

Hi All

I've got a problem with my chainset each time the cranks rotate I get a sqeak form each side, it only happens when I put a load on the pedals, the sqeak occurs when the crank, chain ring side is at the 20 past position and the left hand side, given that it's rotating counterclockwise same as, 20 past. If I push and pull it disapears, but then returns after a few minutes, The chainset is the Shimano Tiagra groupset, 18 speed. The constant squeak is now getting on ones ****. I've eliminated the saddle post, (in case it was me shifting weight about) I've cleaned the chain and rings, and cassett oiled it all up It's then ok for a mile or two then squeak squeak, I've tried GT85 in all sorts of places, I've just changed the pedals so it can't be them. I can't find any play in the bottom bracket spindle. My LBS has had a look at it but it wasn't all that bad then and due to work I cant get back to him till late on next week.
Any ideas.

[Steve]

Try taking the chainset off, then remove the bottom bracket, & re-assemble. Might work, might not.

[UrbanManc]

Any ideas.

Yeah .. sell it ... and stop waking me up

[aesmith]

What type of chainset and bottom bracket?

If its a square-taper BB then I would try pulling the cranks, giving a really good clean of the mating surfaces then a smear of grease (or wax) before reassembling.

Going one stage further, take off the chainrings an again clean and grease or wax the mating surfaces and fixings.

TonyS

[anniesboy]

I had this with a splined chainset a smear of grease solved the porblem,do the same with chainring bolts.

[thirdcrank]

Before dismantling the BB I'd try turning it with the chain off. That should tell you whether it's inside the BB or somewhere else. Also, without the noise of the drivetrain, you might find it easier to pinpoint the source of the noise.

As it's only happening under pressure, is it something to do with the frame flexing slightly, e.g back wheel rubbing mudguard or brakeblock?

[ferrit worrier]

Hi Guys

UrbanManc I'm typing very quietly for you

Thanks for your advice This mornig before setting off I gave the bottom bracket a squirt of GT85 between the crank and the bearing cup on both sides then a liberal squirt of motor oil to follow, I let that soak arround while I had my breakfast, and Wa la no noise, I think it must be somthing to do with the spindle. I'm off to try and find the shimano website and download the destructions for the BB setup and take it apart. Sad to say apart from the old MTB that I had the last time I stripped a Bottom bracket it had cotter pins I'll let you know howI get on.

Cheers

Malc

[aesmith]

Don't leave it too long. If its creaking then there's some movement, and that can only get worse.

[ergle]

I had a similar problem with my Specialized 5 year old mountain bike. I suspected the BB, so removed it, couldn't detect any play in the bearing - put it back, then rode the bike across SW France.

This was a mistake - the creaking sound was indicative of the BB bearings starting to wear out. It got a bit worse as I ascended the Col D'Aubisque, but at least it held up for the rest of the trip. On returning I replaced the bearing unit to solve the problem