Bicycle Mechanics - switching from a triple to a double

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retnav94
12-06-10, 08:43 AM
Buying an 05 cannondale r700 that I was told has a triple crank. (have not picked it up yet). The bike is described on the cannondale site as having a double, a different model has the triple. Anyway if it has a triple will I be able to put a double crank on it without changing everything? Has 105 fd and an ultegra rd. I have done a search but did not find what I was looking for. Thanks

canopus
12-06-10, 08:51 AM
You might have to change the front shifter but I can't think of a reason why you would have to change everything...
bradtx
12-06-10, 09:00 AM
retnav94, I would think a BB change also for the swap.

Brad

fietsbob
12-06-10, 10:54 AM
Proper chain line is the space between 2 chainrings on a double, lined up with the center of the rear cluster.

on a triple , the middle chainring is lined up with the center of the rear cluster.

so you may be able to buy different chainrings and a different BB and use the triple arm,
leaving off the 3rd chainring.

But current trend is fixing the BB spindle tube to the right crankarm.

Then you need buy the whole set.. the BB bearings on those are External.
Al1943
12-06-10, 11:23 AM
If you want a double buy a double. Changing a used bike from a triple to a double may cost enough to make the purchase a bad idea.