I finally got the bike in the mail and assembled it, and the bottom bracket is indeed a sealed square taper. I'm assuming it is at least similar to the original MegaExo BB, but I can't tell for sure. I dont yet have the tools to pull the crankset off, but here is a picture of what I can see of the bottom bracket and the current crankset. I'm still unsure of the current crank, it only says "Rocky Mountain" on it and google searches turn up nothing related to a crank of that brand... I'm wondering if it is a MTB crank, which would be extremely strange since the bike arrived with Bontrager race tires, so I doubt the previous owner was doing cross on those. The front derailleur is the original shimano 105, so I think it will fit a 34/50 fine, which is the size I am looking at now.




I currently see two options with what is currently on ebay. There is a vero compact 50/34 (spindle length of 110) for $65 which I can probably just put right on? I'm not sure the spindle length of the bottom bracket, is there any way to measure it? If I put the crankset on a spindle thats a little bit off the recommended length will that be disastrous?

The other option is wait for a higher quality crankset (Maybe a gossamer, or a lightly used carbon team issue) to come on sale and maybe replace the bottom bracket as well, but that would be twice as expensive and I'm not sure if it really worth it.