Originally Posted by
dansafe
Need help with gearing: Got back into cycling last year, to find the old legs are not what they were in the 1970s...duh.
So, due to all the newer style bikes out there, my Raleigh Pro ("74") has original gearing 52/42 chainrings & 13-28.
Is there any suggestions in order to lower my ratios yet keep my gear Campagnolo stock?
Thank you for any response or solution offered!
The Triplizer chainrings, a suitable 74BCD inner chainring, and a longer bottom bracket spindle plus adjustments to your RD/FD are pretty much all you would need. The Redclovercomponents.com website has the triplizers which are copies of TA units of old. They are probably the least expensive way to get a triple setup with gearing below 36 easily. The early Campagnolo Nuovo Record or Record spindles were 118-119mm wide, so for your Raleigh you would need to switch over (I think) to the thin BB cups, not the rifled thick cups. I suspect the BB spindle would be numbered 68-SS-120 X3 (Italian version is 70-SS-120 X3). The later 68-SS X3 or 70-SS X3 are 124-125mm wide, use the thicker cups, and put the chainline out a bit further for 6-7 speed freewheels.
Dry test fitting is important to be sure you can clear the chainstay with the inner ring.
Chainwrap will be important considerations, also the type of chain used, many use KMC (Z30/31 or Z50/51) or SedisSport (SRAM) types used for 6 speed as they are a little less flexible and shift better in this application. The use of a Master Link makes it easy to take off and service.
Bob Freeman from the CR group can also precision drill standard Campagnolo NR/SR drive side cranks to use a 74 bcd chainring. It requires specific types of standoff spacers and 10mm regular NR chainring bolts. As most 74bcd chainrings come from MTN bike applications, they need to be drilled out from 8mm to 10mm. Be sure to get rings with already chamfered holes on one side to seat the chainring bolts properly.