I was at the LBS the other day and a leftover C-dale Synapse Carbon Rival caught my eye. Anyone have any experience/opinions on this bike? I read some online reviews, and a few mentioned that standing up and hammering can get the chainstays flexing and bouncing, but only a few reviews mentioned this. Most of the reviews talked about it being lightweight and comfortable, both qualities I'm looking for... Also, the bike is equpped with Mavic's Aksium Wheel-Tire-System. Anyone know anything about this? If I don't lke the tires can I just swap them out without issue?