JoeF45

Hello, everyone;

I'm aware that there a several threads related to installing UT cranksets, and have read them all diligently. None has directly addressed my problem, so here's a new thread.

I've got a new Campy UT compact double crankset ready to go on my old Cannondale, and this morning had a shock when I put a digital caliper on the empty English threaded BB shell and found it was 69.07 MM wide.

Campy's directions make it plain that the width of BSC shells should be between 67.2 and 68.8 MM for the UT installation to be successful. Whether you torque the cups (preferred method) or hand-tighten them with much Loctite 222 (Metodo Alternativo), the directions don't address overwidth shells, except to recommend facing them!

The difference of .27 MM is .106 inches, and in machining terms, that's a lot! My guess is that the teeth in the Hirth joint between the semi-axles maynot fully mesh, and that sooner or later, I'll have a real problem, with many warning sounds from the BB.

One possibility might be to remove the "wavy washer" to make up the distance between the bearing cups.

So here are my questions:

1. How serious is this? Am I just hyperventilating over small stuff?
2. If it's serious, does removing or changing a spacer (wavy washer or something else) make any sense?
3. Does the extra space have any effect on the installation method? That is, if I decide to install the UT on the currently overwidth shell, should I definitely use torquing, or Loctite?
4. Are there other things I need to know?

If anyone has dealt with this, and can share experiences, I'm very eager to hear your comments or suggestions.

Thanks in advance, as always.

Joe F

Late details:

Got out my 1-2-3 blocks, which for a machinist give a very accurate 1", 2", and 3" dimension in a hardened and ground piece of steel. Turns out the caliper is dead-on, giving 1.000"/25.4 MM for the 1" dimension, 2.000"/50.8 MM for the 2" dimension, and 3.000"/76.2 MM for the 3" dimension.

But my math is suspect, as one sharp-eyed poster noted. The BB shell is out .0106, much less an effort to reduce.

Thanks again to the several posters who have helped very much. My LBS has a shell-facing tool and the experience to use it. Bike will go the BikeStand next week for some machine work.

Joe F

Final Late Details: Successful facing, successful install

I like to close out a thread with a result, so here's what happened.

My LBS agreed that the shell was overwidth, and used a very impressive tool that both chases the threads and shaves down the shell with cutters on both the drive and non-drive sides. They did so, very nicely and very carefully. I took the bike home, and the UT bearing cups and crankset went in within minutes.

I torqued them to Campy spec, both the cups and the hollow screw that holds the two piece axle together. Put a new Record chain on to match up with the new crankset and the new cassette, and took the bike for a couple of rides.

Not sure I can feel any real difference. The UT crankset and BB is lighter than the old square taper version (by about 120 grams!), and it *may* be a bit stiffer. I got out of the saddle on a couple of climbs and the bike certainly doesn't flex much.

Thanks to all for the comments and advice, and thanks to Bill S and his crew at the BikeStand.

Joe F