Bicycle Mechanics - Persistent bottom bracket creak

Ok, I know this pops up at least once a week, but I feel like I've exhausted the options. I ride a Cannondale R300.

Steps I've taken:

1. tightened seat rails, seatpost binder bolt, crankarms, stem, handlebar clamp.

2. lubed pedals

3. replaced old (crappy) BB with Shimano UN73 (a good one)

4. pulled the new BB 3x, repacking with grease, then teflon tape, then grease again (lots - basically filling the BB)

The only time that I've had any reduction in the amount / frequency of creaking was right after reinstalling with teflon tape. However, this wore off after a while and the creaking returned.

My questions:

1. How much teflon tape do I need to use? I did 3 -4 turns around the threads, thinking that was enough.

2. Has anyone had trouble with the plastic NDS cups on Shimano sealed cartridges? Should I buy another BB with an alloy NDS cup?

Help!

Suggestions:

1 - Grease seat rail contact points on saddle.

2 - Grease seat rails, then tighten.

3 - Swap pedals for another pair to make sure that it's -really- not the source.

Could the hanger tube be out of round? Have you checked that the faces are parallel?

Also check carefully for cracks.

No need to grease the seat rails. Just see if it creaks while you're out of the saddle.

Or it could just be the bike. I have a cannondale badboy and it creaks, always at the same spot in crank rotation. Checked the bb, cranks, seat etc and finally took it in the the lbs to solve the problem.

It's a creaky bike. No cracks, just creaks. I was told some bike are like this.

face and chase the BB threads. use liberal teflon tape or the liquid teflon stuff. make sure its tightend to spec. then start looking elsewhere

I'll try the pedals, and I guess my last resort will be taking it to the LBS for a face and chase. I can't accept that it's creaky - I think I'd go insane. Thanks for all your help.

could be the crank itself creaking

Use a torque-wrench on teh crankarm bolt. I bet it's not tight enough. You really need a 12" automotive-style ratchet-wrench. Those puny 6" double-sided Park wrenches cannot let you get enough torque on those bolts. Search for "loose crankarm" and see how many cases of this pops up all the time.

I have seen this problem in older Cannondale bikes. One area that you might need to look at is the replaceable rear derailleur hanger that is attached to the chain/seatstays by two tiny allen screws. These occasionally work loose and cause the creaking noise. Feels as if it was coming from the BB. One way to fix this is to tap the threads for slightly bigger screws. Best of luck!

after greasing everything, try pulling and greasing the chainring bolts- that has worked for me in the past.

Because vibrations travel so well through a metal frame, the noise could be coming from many places.
The last time I had this problem it was the chainring bolts. Removed, cleaned, greased, re-assembled, creak gone. Another time the noise actually came from the stem.

Nobody has mentioned greasing the seat post yet. Grease the entire length that is inside the frame and wipe off the excess after inserting.
Check your stem. You don't want to grease here but you do want to make sure the bolts are all tight. I had a stem creak that was the result of an improperly machined stem. The clamp had a high spot so it was impossible to tighten properly. I replaced the stem with a decent four-bolt-clamp stem to fix.

Checked all the welds for cracks?

Is your saddle a Brooks? The front tension nut on my B17 creaks when I'm peddling hard.

I'm fairly convinced it's the BB because the creaking went away for a period after my second removal of the BB and reinstallation with teflon tape. But then it started again.

These are great suggestions - I'll check derailleur hanger, crankarm (although I really cranked those on there), seatpost (it's lubed, but I'll relube). I've tightened the chainring bolts, but I could pull them, clean, lube and reinstall. Not a bad idea. I'll keep folks posted. Thanks again.

I had this problem and it went away when I greased the area where the stem clamped onto the handlebars. Another time it was because I had not tightened the skewers enough on the rear wheel. The wierdst was when I was a wits end only to finally discover that it was the tab on the zipper of my jersey ticking against the zipper with every pedal stroke (and yes I am not the world's smoothest pedaler). Tracking down where a noise comes from on a bike can be totally frustrating. I wish you the best of luck.

Use a torque-wrench on teh crankarm bolt. I bet it's not tight enough. You really need a 12" automotive-style ratchet-wrench. Those puny 6" double-sided Park wrenches cannot let you get enough torque on those bolts. Search for "loose crankarm" and see how many cases of this pops up all the time.

Close, but my bet is you have inadequate bottom bracket torque. My reasoning is because teflon tapeing the bottom bracket was a temporary fix. Torque spec. for bottom brackets is 30 to 35 ft/lbs. That's a fairly significant amount. Think about a 30 pound weight hanging from the end of a foot long wrench. Crank arms and bottom brackets are two bicycle parts that I would personally undertorque if left entirely to my own judgement.

Incidentally, the crank arm thing is a biggie too. That's also a 30 to 35 ft/lb spec. With a 6" allen wrench you need to push down with 60 to 70 pounds of force (with one hand) on the very tip end of the wrench. Some allen wrenches aren't even 6" long so you'd have to push even harder. Not likely.

I'm sure I've torqued the BB enough as I have a setup for my BB tool with a 1 1/2" socket and a 25" breaker bar. No shortage of leverage there.... It's sweet, BTW, and I'd highly recommend. I will tighten the crankarm bolts and see what happens. Thanks for the advice.