Two Wheels - Six Strings

Random news and thoughts about various two-wheeled projects and music, especially my band, Skull Full Of Blues.

Wednesday, August 05, 2015


 I've been back from my big motorbike trip for a week, tomorrow. I have a few photo-heavy posts planned. But, I am still processing the trip in my head, planning how to arrange the info/photos. If you are interested, those posts are on the way. In the meantime, here's an oddity; a bicycle post!

I will say, without reservation, that I love my Funk bike. I designed it, had it built by a couple of the finest frame builders in Colorado, and I have ridden it for everything from 24-hour mountain bike races, to the Copper Triangle, to commuting back and forth to work. It has the cachet of being the only one of its kind (it was  prototype for a production frame, but that never happened). And if it was a woman, I'd marry her, assuming that she would have me.

But, a while back, the bike developed a bit of a creak. It was subtle, at first, and I thought it was the leather on the saddle rubbing against the rails. As time went by, the creak became more pronounced, and it really started to bug me. A couple of days before my vacation, I got the bike out and tried to fix the problem, by replacing the seat, removing and regreasing the seat post, etc. It continued to make noise, so I put it in the shop building and figured that I could look at it after I got home.

Today, I rode the bike to work, and the creak was worse; incessant and louder than ever.  For the first time, it would continue to creak, even if I got out of the saddle. At that point, I started considering the bottom bracket/crank/pedal interfaces as the possible source of the creak.

On the way home, the noise was driving me crazy. It was so bat that I was having thoughts of just abandoning ship and walking home. There is just something infuriating about a high-end bike with a low-class problem...

When I got home, I put the bike in the stand, and pulled the cranks. I figured that the first thing to do was to remove the bottom bracket and put some fresh anti-seize compound on the threads. Aluminum and titanium do not interact well without a buffer between them.

The bottom bracket is a Shimano external-bearing style. The cups could be creaking in the frame. Or, the crank arm could be creaking on the spindle. Or, as I figured out, once the bb was out of the bike, the bearing on the drive side could be contaminated and grinding itself into powder, while doing the bearing equivalent of screaming in agony: creaking!

Printing "Do Not Disassemble" on a bicycle bearing and selling it to me is the equivalent of printing "Do Not Chew" on a bone, and tossing it to a dog. I've never met a bike bearing that I didn't eventually see the inside of.

I didn't photograph the surgery, because I was more intent on fixing the bike than I was on posting photos of the process. Suffice it to say that they probably don't want you to disassemble these bearings because they are embarrassed by how small their balls are. The ball bearings in these bottom brackets are about 3/16" or 1/8" (I didn't measure), which is pretty small for the loads to which they are subjected.

I cleaned the bearing, then greased and reassembled it, and reinstalled the bb. No creak on the test ride!

But, I think that it is a temporary fix. The bearing is pretty much toast, so it needs to be replaced.  A new set of bearings is on the way. At about $20.00 for the complete bb, I don't see any need to ride around on a worn-out bearing.

Considering the wear and tear that I have put this bike through, I have no real complaints about the lifespan of the original bearings. If the second set takes as much abuse as the first, I will be happy!



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