Worrisome noises from an old steelie.

[GBC]

I've got an old Triumph racer, which I'm very fond of, but which has quite suddenly developed some worrying noises coming from the crank/ bottom bracket area. They are mainly an unrhythmic but almost constant 'click' accompanied by a creaking sound. They're most apparent when I'm applying greatest pressure, such as taking off from a stop or climbing hills. There isn't any noticeable 'rumble' from the bearings.

There doesn't seem to be anything fouling the drive chain anywhere, and the only possible cause that I know of was that my brother broke the chain when he had it on loan recently, when he got caught in the highest gear at the start of a steep hill. (Gear changing is by means of a non-indexed frame lever.)

Any ideas or thoughts on the possible cause(s) would be greatly appreciated.

 

[Rickshaw Phil]

Firstly, have you checked the frame over since the chain break to be sure the frame hasn't cracked? In honesty I doubt it's this as it would be a worst case scenario, but check anyway.

Although you've said there is no rumble, it may be worth stripping, cleaning, regreasing and adjusting the bottom bracket bearings as (in my experience) the old cup and cone bottom brackets can cause odd noises like this when they get dirt in or go out of adjustment.

The next thing I'd suggest is doing the same to the pedals as they can also be a source of odd noises apparently from the bottom bracket area and generally only do this under power.

 

[GBC]

Firstly, have you checked the frame over since the chain break to be sure the frame hasn't cracked? In honesty I doubt it's this as it would be a worst case scenario, but check anyway.

Although you've said there is no rumble, it may be worth stripping, cleaning, regreasing and adjusting the bottom bracket bearings as (in my experience) the old cup and cone bottom brackets can cause odd noises like this when they get dirt in or go out of adjustment.

The next thing I'd suggest is doing the same to the pedals as they can also be a source of odd noises apparently from the bottom bracket area and generally only do this under power.

Many thanks for that Phil, and as per your advice, I'd started to reconcile myself to a total strip down. If it turns out to be anything interesting, I'll let you know.
George.

 

[YahudaMoon]

I guess you need a complete new bottom bracket. I usualy get about 2 years out of mine though that' doing about 200km + per week or about 20'000 km over 2 years

Im surprised its still running, I also wouldn't bother just changing the bearings, Id get a complete bottom bracket as new bearings don't always fit in worn out cones

That is if it is the bottom bracket ?

 

[GBC]

Hi YM, yes, that's the way I'd been thinking.
I've also noticed now that the crankset seems to be off plane by 2 or 3 degrees, so I'm now beginning to wonder if his foot slamming the pedal down when the chain went, has been enough to put a bit of a bend in the spindle. Like me, my brother would never be called under-nourished (we're both about the 16 stone mark.)
George.

 

[Rickshaw Phil]

Ah, this doesn't sound ideal. I presume that being an older bike it is a cottered axle. There don't appear to be a lot of new spares available for these (What I've found) If this isn't suitable it's a case of looking for new-old-stock spares or updating to something more modern.

If it was for me I'd be happy with square taper as it's readily available, inexpensive and robust enough for most people.

 

[swee'pea99]

The bottom bracket to go for is one of these - http://www.ebay.co.uk/itm/Shimano-B...sure_cycling_bikeparts_SR&hash=item27c96618b4 - they're cheap as chips, and bullet proof. Make sure you get the right axle length. And be careful when you remove the old one - the RH cup, as you sit on the bike, has a reverse thread: you have to turn clockwise to get it off.