2021Cannondale synapse alloy is 750 and is in pristine condition. 105 mechanical and mechanical disk brakes. It is QR alloy frame which seems dated for 2021 model year.
2015 Cervelo is 1500 but a carbon frame and Ultegra di2. I'm OK with rim brakes as this won't be my commuter. Seller claims crankset has been upgraded to Rotor and the wheels are Mavic krysium. I'm not sure how good or Desireable those upgrades are as the price is a bit over market value.
Both are my size and budget just not sure if the cervelo is worth twice the price. I'm 5'7", my old bike is a 53cm Salsa Journeyer. It's comfortable t but I just can't seem to crack 15mph average on the flats.
by Lawrence_skywalker