Bicycle Mechanics - diagnostic help: RD?

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View Full Version : diagnostic help: RD?


thebeatcatcher
09-27-08, 04:29 PM
I am getting a dullish clicking sound that sounds/feels internal from the rear that happens consistently when I am pedaling only, about 5-8 clicks per pedal stroke. The drive train is old suntour, friction shifters, and 6spd. So far this is what I've done:

1) Repacked BB (then decided it was coming from rear)
2) Disassembled freewheel, cleaned and oiled
3) #2 failed so I replaced the freewheel (with a new one)

I was thinking about rear hub bearings, but I don't get the noise when I coast, only during pedaling and the wheel spins fine. Maybe that'll be #4 as it won't hurt anything.

The other option is the RD, has it gone bad? Help please and sorry if this has been done, I really have looked around here (hence #'s 1-3).

Thanks.


joejack951
09-27-08, 06:40 PM
Check your chain for stiff links and for wear (measure 24 links, should be 12 1/16" max). Also check your rear derailler's alignment, both the rear hanger and it's position relative to each cog.

JustChuck
09-27-08, 06:42 PM
Look at your BB bearings and your pedals. On a bike the vintage that would have Suntour, those items may need some attention, my bet is the BB


thebeatcatcher
09-27-08, 07:06 PM
Check your chain for stiff links and for wear (measure 24 links, should be 12 1/16" max). Also check your rear derailler's alignment, both the rear hanger and it's position relative to each cog.

There aren't any stiff links, but I'll check the rest. Thanks.




Look at your BB bearings and your pedals. On a bike the vintage that would have Suntour, those items may need some attention, my bet is the BB

I just repacked/replaced the BB bearings and the pedals are used but are relatively new, not like the 20yr old bike. It's definitely coming from the rear.

JustChuck
09-27-08, 07:22 PM
I did not see that you had rebuilt the BB.
5-8 times per pedal stroke is only about a third of the chain length(on the small ring) So the chain would need to have isues in multiple spots for that to be the problem. Could be the der pulleys, 10 teeth, one pedal stroke would be 39-42 teeth, so 39-42 links. If you had a bad tooth or damage inside the pulley, it would show up about 4 times per stroke. A little low but close to your number.
Can you support the rear wheel so you can watch the drive train as you pedal and look for anything that might cause your issue.

If you have a set swap some other pedals, just for grins.

operator
09-27-08, 07:34 PM
I am getting a dullish clicking sound that sounds/feels internal from the rear that happens consistently when I am pedaling only, about 5-8 clicks per pedal stroke. The drive train is old suntour, friction shifters, and 6spd. So far this is what I've done:

1) Repacked BB (then decided it was coming from rear)
2) Disassembled freewheel, cleaned and oiled
3) #2 failed so I replaced the freewheel (with a new one)

I was thinking about rear hub bearings, but I don't get the noise when I coast, only during pedaling and the wheel spins fine. Maybe that'll be #4 as it won't hurt anything.

The other option is the RD, has it gone bad? Help please and sorry if this has been done, I really have looked around here (hence #'s 1-3).

Thanks.

http://www.sheldonbrown.com/creaks.html

This is in the sticky. Look harder next time.

thebeatcatcher
09-27-08, 09:50 PM
http://www.sheldonbrown.com/creaks.html

This is in the sticky. Look harder next time.

His site is always the first one I check and I checked that page and (after I tried a few different things) none of those scenarios fit.

thebeatcatcher
09-27-08, 10:57 PM
Check your chain for stiff links and for wear (measure 24 links, should be 12 1/16" max). Also check your rear derailler's alignment, both the rear hanger and it's position relative to each cog.

It was the chain. It was too stretched out so I switched it with a newer one I had lying around that was within your measurement, so problem fixed (for now) and I hope it stays that way!

Thanks! I was starting to get frustrated.

Panthers007
09-28-08, 12:19 AM
I was about to say...Anywho - whenever you replace the components on the drivetrain, always replace the chain. The old one's will have merged in shape with the other (old) components and have a "custom" shape to them from this wear. Even if it's not stretched - New Chain.

Happy Cycling.

joejack951
09-28-08, 07:42 AM
I was about to say...Anywho - whenever you replace the components on the drivetrain, always replace the chain. The old one's will have merged in shape with the other (old) components and have a "custom" shape to them from this wear. Even if it's not stretched - New Chain.

Happy Cycling.

BTDT :) It's great to be able to share experience.