LBS bb advice?

[Onno]

I've been trying to track down a bottom bracket to replace the clicking DA bb on my Concours. Previous advice from this forum has steered me towards the Ultegra 6500 bb. My regular webstores are out of stock, and by LBS can only supply a 5500 (105). The mechanic there suggested that I just take out the DA bb and relube it. I thought these things were sealed and thus unfixable. Who's right?

Thanks!
Onno

[christian]

The DA splined bb is not sealed. It is a cup and cone style bb with round and needle bearings. You should definitely relube it. It's a great bb, if you don't ride in rain much. Be aware to not torque down the cups too muchh.

I swapped mine for a 6500, because I'm too lazy to relube my bb regularly. But the DA spins much better...

- Christian

[Jeremy]

Hi Onno,

The Dura-Ace 7700 bb is sealed, but it is not a cartridge type bb. Thus it is rebuildable. You can disassemble it, inspect the cones for wear and rebuild it. Back in the day this was a normal procedure, i.e. a bottom bracket overhaul. The word sealed is often misused. Modern cup and cone bottom brackets and hubs are all "sealed", but they do not use cartridge bearings. If you do this, do not attempt to remove the roller and ball bearings from the cup. When you remove the bb from the frame, you can do a pretty good job of cleaning the exposed bearings without removing them from the cup itself. After it is clean, use a high quality waterproof grease and make sure that the roller and needle bearings are greased. Reassembly is basically the same as an old style bb, but the needle bearings make the adjustment harder to feel. However, if the mechanic is careful, the bb can be adjusted properly. It is also impoortant that the bb shell is properly faced. Unfortunately, it is common on even high end frames for the shell to be unfaced.

Jeremy

[weisan]

http://www.parktool.com/repair_help/FAQadjbb.shtml

[Onno]

Thanks for the help. I'll try pulling it apart and regreasing before I replace it. I've done this with older bikes a few times and managed not to bungle the job, so it's worth the try.

Onno

[Too Tall]

What Dave said with a caveat.....go slow and be prepared to chase itty bitty ball bearings all over the joint! No kidding, the bearings are very small and only retained by a minimal plastic retainer so any jostling will send them flying.

Prepare a shallow bio-degradable bath and gently agitate them and rinse...air dry...best bet.

[Jeremy]

There is a small plastic snap ring that keeps the bearings in the cup. As long as you don't remove it or displace it while cleaning, the bearings should stay in place while cleaning them. Good luck.

Jeremy