Downhill Time Trial Bike
This is
the bike I intend to see how fast I can time trial down an 8.6 mile road
that drops 2700 feet. Tried this once with standard 53x11 gears and then again
with the 67x11.
The key is the 67 tooth chain ring, as
shown below. Otherwise, it’s an 07 Cervelo P2C, with Zipp clincher disc and 808
front (999 set), and mostly Campy drive train.
This chain ring is huge! That’s a
standard 135 bcd Campy Record crank, with a 172.5
crank arms. Had to add 8 links to the chain to make it work. Made by MDT out of
England. Took a month to get. Was amazed that it cleared the chain stay with a
standard bottom bracket. This thing is massive, too, which I suppose won’t hurt
a down hill effort.
Also had to pull off the front
derailleur. Will have to shift the front by manually moving the chain. Chain
ring is made with tooth profiles designed to be run with no derailleur, to
retain the chain.
Here’s the 67 next to a 53.
Almost 11 inches in diameter.
The small ring is a 42. Makes it look
tiny.
Cockpit. The SRM should record speed and
HR, but no power or cadence (Could not use the big ring with the FSA SRM crank
set).
