You can usually get a Campy NR to work with a 13-28 FW and a 52-42 crank, but you have to get the chainlength absolutely right, which usually takes some experimentation. The Campy SR cage had a slightly different geometry and will handle a couple of extra FW teeth.
Regards,
Jerry Moos Houston, TX
I decided to build up an old trek frame I had with some campy parts. I used more of a touring freewheel but the NR derailleur doesn't seem to be able to handle the larger cogs in the rear when the chain is on the small chain ring up front. I've always used one step racing type freewheels with campy derailleurs and I've never encountered this problem before. when it is in the gears stated above the pulley hits the freewheel. are these derailleurs just not meant to handle such gear ratios or do I some how have this set up wrong? what are the gearing limits for these?
marc garcia
chicago IL