I'm building up a touring bike from old bits and bobs. I have a 50/34 10 speed compact and 105 brifters, but am considering going triple. Can a double brifter be converted to triple, and if so, how so?

On slightly unrelated note, if I stick with the compact, then I'd like to get a bigger rear cassette. The biggest shimano do for my kit (5600/6600) is 12-27. Are there any bigger cassettes? Or are the latest 11-28 cassettes compatible?

Ta!!!

Didn't think you could convert a double STI (please don't call them brifters, it's a nasty Americanism and makes me heave), to a triple; the amount of travel in the lever/cable/mech isn't wide enough to cope across a triple chainset….

However, looking at the new 105 stuff, it seems that the left hand lever is able to do double or triple, so it depends how old the STI units are.

As for rear cassettes, look at mountain bike ones….

Not possible to convert IIRC. The 11-28 cassette should be OK, but check which model of chain to use as there some incompatibilities with 6600 and 6700.

It works on my Genesis Croix de Fer, changed the compact(hideous jump) double for a closer triple, the front mech will need to be for a triple but the STI units work fine