Bicycle Tutor

Folks,
My bottom bracket (I believe) maybe on the way out (again). Sometimes it clicks with every one crank revolution (hence suspect bottom bracket), however at other times it does not…
The BB is Shimano XT sealed. Any ideas on what may cause this – perhaps a flattened bearing? Sometimes it can be soundless for days… Other times it is loud and most annoying… When it is making noise (not right now presently), the noise is amplified when peddling harder.
The BB was replaced only two years ago (I think, might be three – can’t rightly remember) and I only (now) use the bike for regular commuting…
Bike is Kona Caldera 1999 (with bits and bobs replaced and still going strong!).

Could just be a loose crank arm or pedal. Check those before you assume it's the BB

Just repaired my BB. Was making a noise on every down peddle for about the last two months. Was driving me nuts. Have a FCR3 Giant with a cartridge type BB. Removed and cleaned the carriage and bracket. Reassembled and torqued it to spec's. No more noise. Probably was the torque. When I pulled the crank's, I grabbed both sides of the spindle and with a lot of effort ,was able to get it to move just a bit. We'll see how long this will last. I torqued the BB to 30ft lbs and the crank's to 35ft lbs.

Dave,
I thought about the pedal, but since the ‘click’ happens at the same place on the crank I suspect BB. Crank on drive train side has recently been removed to fit new middle chain ring – by LBS (I didn’t have the time to do it myself). In retrospect, this (reported symptom) has occurred before that change…
I think, when I get the chance, I’ll simply change the pedals (to a shit set) and see if it still occurs…
If it does, I’ll check the crank arms as your suggestion – I mean at the moment the seem/feel fine…
Are Shimano BBs any good – I’m sure I don’t cycle hard on them but it has been three years (perhaps)…? Would you recommend another manufacturer for replacement…?

Theo,
Thanks for your info – this indeed could be an issue but the BB was fitted three years ago… Unfortunately, I do not have the tools to remove, replace and re-tighten it to the correct torque. I’ll have to have a think…
The ‘clicking’ is now permanent, after the above checks prove negative, I’ll go for a new BB…

Shimano BB's are fine. The quality varies with price of course, but they typically last years.
You might try slipping the chain off the inner chain ring so you can rotate the cranks without anything touching them. If that feels very smooth with no side to side play, it would indicate (but not prove) that the BB is fine.
My first guess would be loose crank arm or pedal. Sometimes re-installing the pedals with a little grease on the threads will cure this. But as stated above, these noises can be tricky to track down. good luck

I am also having problems with a click noise coming from the bottom bracket, cranks or petals. I had this same issue last fall and the LBS replaced the bottom bracket. the sound started coming back the last week or two. As before the sound is most frequent on the hot, humid days. I am looking for some method to determine if its the bottom bracket, cranks or the petals. everything seems to be tight.

For anyone who is interested, I talked to my LBS and they said that another customer had the same problem. After replacing a lot of parts and many calls to Giant, they figured out that adding a little thread tape to the took care of the problem. It also took care of my problem! Supposedly it's related to the humidity and it'd make sense since its been humid all week.

Guys,
I haven’t had chance to thoroughly check the situation out yet – I’ve had barely the time to clean the chain but that’s been done…
It too has been humid around here lately, however the clicking has gone away (wolfc - maybe with the slightly colder weather that we’re having here now)! I have an opportunity to change the BB on Friday but as I said things seem to be OK right now…
This whole thing puzzles me slightly as before the clicking has gone away with no attention/alterations (knowingly – you’re always adjusting things). Drive chain is superb and bike is great (for an oldie) at the mo…
Marc Dominic.

I thought I was having a BB issue too. Then my chain snapped so I replaced it with a new one and the BB feels nice and smooth again.