|Ti Frame + record BB = loud noise||Shad|
Jun 28, 2001 11:11 AM
|Hi All, |
I checked all the past postings relating to previous questions on this topic but am looking for some clarification.
My supposedly stiff frame (LS Palmares) and 2000 10 speed BB make a very loud "ka-chunka, ka-chunka" noise when standing to climb or accelerate.
The chain and rear cogs/derailleur are very clean, so I'm quite certain the noise isn't coming from there. It's not the seat rails, pedals, stem or the wheel hubs. The sound is much more than a "clicking" some have described, but it's still very smooth when spinning. I also checked the chainring bolts for tightness. I had the local LBS look at it and they SUPPOSEDLY applied some anti-sieze to the threads. It hasn't made a difference. In the review section, one guy mentioned he had been through four of these BB's. Could the bottom bracket be bad? If so, should I replace it with a chorus? The LBS sort of scoffed at the teflon tape idea. Should I give that a try?
Any ideas or suggestions are very appreciated.
Apple valley, MN
|re: Ti Frame + record BB = loud noise||grz mnky|
Jun 28, 2001 12:02 PM
|Well, your'e on the right track. Usually it comes down to the BB, but any drivetrain component between your foot and the rear tire can do it. Bottom line: Something has too much play. The LBS can scoff at teflon tape, but many of us use it with good results. Anti-sieze can also work. However, neither of these solutions are any good if the BB isn't properly torqued - the cartridge will still rock around between the "fixed" cups. It is entirely possible that the BB spindle is loose with respect to the bearings, but this is a lot less likely than the other sources. You need to check pedals, spokes, hub bearings, ensure that the cogs are tight. You also should check the headset and front wheel since it's standing/power related. Swapping out some components witha second (and known good) bike can be a qucik way to find things. |
Ultimately it's bit frustrating trying to figure it out, but very rewarding when your machine runs silently.
|Check the frame?||Cima Coppi|
Jun 28, 2001 12:08 PM
|You did not say if you looked at the frame, but just check the welds all around and under the BB shell, just in case. I may not be this, but stranger things have happened. |
Also, I did have a similar experience with noise sounding like it emminated from the BB, but it ended up being a broken rear hub axle. You may want to check there as well.
|Make sure the headset is tight||Dave Hickey|
Jun 28, 2001 12:31 PM
|A loose headset can sound similar to a bottom bracket, expecially if it happens when you climb or accelerate. Stand out of the saddle and rock your bike without turning the cranks. If you hear the noise, it could be the headset.|
Jun 28, 2001 3:03 PM
|Thanks for the advice, I'll try to figure it out when I get home tonight. Hope it's not the cracked frame though! |
|re: Ti Frame + record BB = loud noise||Kerry Irons|
Jun 28, 2001 6:42 PM
|Is the clunking only a noise, or do you feel it through the pedals? If you're really getting a clunk that you can feel through the pedals, then you should be able to reproduce this by twisting things with your bare hands. If you don't feel it through the pedals, then I would look to something besides the drive train. At any rate, double check that the BB was torqued enough. 70 n-m is more than you would normally do "by hand" - it is really leaning on a big wrench.|
|Teflon it first...||TJeanloz|
Jun 28, 2001 8:40 PM
|Anybody who scoffs at using teflon tape with a ti bottom bracket shell doesn't have the experience that I would want from a mechanic. This is a KNOWN problem with a KNOWN solution. When I stopped working at the shop, we tefloned every bottom bracket we installed- it won't hurt anything and might avoid a problem.|
Jun 29, 2001 1:11 PM
|I pulled the BB out last night, cleaned it thoroughly, and re-installed with ti-prep, grease and teflon tape. I'm quite certain that the LBS never did anything beyond pulling the cranks off; if they even did that. The crank bolts had some very dry bluish substance on them, everything else was just dirty and dry. If they did pull it apart, they put it back togther without doing a thing or adding a drop of lube. |
I took it out for a short sprint in my "hood" after midnight and I couldn't get it to make the noise again. Hopefully it remains that way for the long rides I'm doing this weekend.
It really does feel satisfying to do it yourself and have it work properly.
Apple Valley, MN
Jun 29, 2001 3:27 PM
|Yeah, very satisfying when you nail the problem. I guess some of us also get similar satisfaction on passing decent info. As many engineers know: there's no point in re-inventing the wheel. This forum can be very useful and the advice is always worth at least what you paid for it.... |
Enjoy the quiet ride!
Jun 30, 2001 1:50 PM
|This is why I don't let the "pros" touch my bikes. I've seen some pretty sad things from knuckleheads at pro shops.