got a 94 cannondale m900 mtb and I am converting it for commuting. I put 1.25 street tires on with a 11/28 8 speed cassette on back. I have a question. I found a compact Gossamer 50/34 crankset to replace the 22/32/42 crank now on it. Will the triple front derailleur work on the double if I just set the limit screws? Do I need a new derailleur? help Please.Thanks.