Interesting. I'm the original owner of a 1978 Trek Tx700 as well. I just recently had the rear drop outs spread to 130mm(as I did on the 560) and upgraded the TX700to DA. The BB spindle on this one had always been 118mm. I changed the BB to 109.5mm as per DA specifications. It has worked out perfectly. I now have the original DA 600 crankset (after many hours at the buffing wheel) on the 560 with recent Ultegra chainwheels. It looks great--kinda retro. I have noticed that the chainstays are shorter on the 560 as opposed to the TX700. I'm sure that this has something to do with the crosschaining debacle. Do you still think I should put the Ultegra crank back on with the 109.5er BB, and what solutions are avail such as different drive sys ratios to counter this problem?