mine is 2 rings at the front and an 8spd block at the back ,iv fitted what i can (easier ratio cassette) but id have to change everything if i wanted a triple ,its the shifters that would cost the most eh,if i just fit a compact chainring its gen a straight swap (i hope),its a reg square taper bb with a reg 105 crankset so nothing fancy ,any reccs for a replacement peeps
and just for curiosity id sell whats there ,any idea what id get cost wise for selling my old set (half decent 53-39 105 and ok condition ?