I installed a Shimano UN91 b-bracket on a Ti Lemond a year ago and have just replaced it (pitting/creaking, etc...) with a UN73. It's what the shop had. The UN91 was a "thread in from the left" which was no big deal. My 2 other road bikes use UN72's, so I'm familar with the installations. The UN73 has a much wider (greater threads) left cup, that will not screw in/set in to the bottom bracket shell as far as the UN91, nor will it set in as far as the UN72's on my other 2 bikes. It has about 10mm or so of thread on the outside of the shell, where as the UN72's were flush to the shell. The 73 is seemingly is a tight as it needs to be - I've used torque wrenches, setting to the pressure as recommended on the Park Tool site. My question is, is having this much thread exposed normal ?. The 73 does use a cup that has a good bit more threads then the UN72's I'm familiar with. FWIW, the crank arms are equal distance from the chainstays (or at least within a few mm of each other) so all looks kosher and the cranks feels solid with no play. Won't ride until I'm sure. Thanks in advance. Steve B.