The 1987 Ironman Expert came with a Shimano 105 gruppo. The BioPace chainrings were 52-42T and the stock MFD12 Uniglide 6 speed FW was 13-24T. The dropouts were 126mm wide.

I got my 1987 IM sans wheels and seat. It had been used by some SoCal tri freak, rode hard and put away wet. The seat post was corroded in place and I had to cut it out.



I had a local frame builder check the alignment and spread the dropouts to 130mm. I'm using a 13-30 Uniglide 7 speed cassette with 48-38T chainrings. I had to change the pulleys on the Shimano 105 RD. Now it index shifts all the gears like butter.




The MSR List Price for the 1987 IM Expert was $520 - a lot of bang for the buck.

The 105 and later 600 RDs have a much wider range than the specs indicate. Here's a 600 with a 12-30T 8 speed cassette and 48-38T chainrings. The steel pulley cages shift a little more crisply than the more expensive RDs with alloy cages.



As mentioned above, you may have to adjust the RD travel stops and the cable fine adjustment. Unless there is a big difference in tooth count you should have no problem just switching wheels.

verktyg