Originally Posted by smashndash

My personal opinion would be to steer clear of the Madone. There’s a thread on here somewhere about BB90 and its issues.

People’s knee-jerk reactions will be to say “that’s a minority of people, they’re not representative of the majority of owners” but the design is flawed, plain and simple. Also, you need to define what is “good”. Simply being able to ride creak free is NOT an indication of a good BB shell. You also need to take into account bearing misalignment, which simply cannot be corrected with BB90. It would be a shame if your BB ate 5-10W more than it’s supposed to or chewed through bearings every 1000-3000 miles. Or if the frame needed work after 10,000 miles of relying on loctite for retention but Trek refuses the warranty due to “improper maintenance”.

I’m not saying the Madone is a bad bike. If they had almost any other open BB standard, it would be my race bike of choice. I’m not saying there aren’t people who have perfect BB shells that spin perfectly. But it’s significantly more of a gamble than if you were to get the BMC with a BB86.

If you have a really good relationship with your Trek dealer and you have a lot of faith in Trek, then I’d say go for the Madone. If you want to take slightly less of a gamble (though I know very little about the BMC), go for the BMC.

Also, the wheels, bar and stem on the SL6 aren’t necessarily the best. You’d probably want to upgrade those within a few years. If you did the same to the BMC, the two bikes would be very close aerodynamically but the BMC would be lighter and probably stiffer, especially with a one piece BB that Treks can’t use.

EDIT: Also, the SL6 seems to have mechanical ultegra whereas the BMC has Di2. Is that true?