And, there are finicky bottom bracket bearing issues, because the seals aren’t stout enough on the non-drive side to keep out gu, water, gatorade, sweat and the result of a fumbly nature (hey…it’s hard when you’re trying to get back on…). The left bearing goes about every 3,000 miles; and the right generally is still O.K. The reason is that BB90 has a lip in the carbon frame on the right side; but not the left. This allows drips, sweat, etc., to get into the left bearing more easily than they can get into the left bearing.

Buy the bike, and a shimano/madone bearing kit. The kit has two seals and two bearings, and you can use both on the left, as the right likely will not be a problem.