Originally Posted by
wrk101
Don't count on stem or seat post fitting. It really depends on the era of the bike, and more. BB may or may not be correct. Raleigh for example had their own standard, which was different than the british standard. And then you have rear wheel spacing. Those changed significantly over the years, from 120mm to 126mm to 130mm to 135mm. Some of the british bikes used smaller diameter front axles too.
Still I continue to find all the parts I need in the form of complete bikes. But often, it just isn't ONE bike. Picked up two today, one made in USA, one made in Japan. Different stem ODs, different seat post ODs, different rear wheel spacing, different headset specs, different wheel OD, on and on.
I can't imagine a 1970s cottered crank Raleigh Gran Prix frame having ANY value. Generally, I target 1980s made in Japan bikes, that tended to use standardized stuff. One I picked up today is a good example. 1985 made in Japan Nishiki, almost all Shimano 600 parts. Frame alone should more than cover cost, but it was a high end model back in the day.
For Raleighs of these vintages, R followed its own standards. A lot had 26 tpi BB, axle, and fork steerer threads. I think I read way back when that the Super Course was changed to more generic threadings around 1973, perhaps the GP as well? It’s worth while to have a thread pitch measuring gauge, pretty cheap via Amazon, from Asian sources. Mitutoyo versus Asian: around 3 times the price for Mitutoyo!
Despite the proprietary threadings, BB cups will often pass inspection if the races are not rusty, and the spacing between the bearings is a one of several standard values. This means you can often swap out the cottered spindle +chainset for a square-taper spindle with cotterless chainset. It’s not elementary to choose a workable spindle, but it’s an opportunity to adapt and overcome. I’d rather see a GP with a Stronglight or TA near-period chainset adaptation, than a staged alloy crank from the lower early ranks of the period Asian bikes. My brother had one, it was a real good ride, but … it becomes “refurbishing an old bike as a rider” rather than respecting what was done in manufacturing a classic.
I was recently scolded on BF, however, for taking the TA path with my 1952 Rudge. Opinions vary widely. But I always think “if I cannot replace a bad part with the original, what can I do that is a period upgrade, or, what would I have done BITD if I had owned this machine and ridden it extensively?
For me, replacing with a decent used cotterless chainset like a Stronglight or TA would have been a no-brainer. Today, I realize there is a lot to think about
: chainline, Q-factor, chainring pitch, chainring war page, tooth condition, chain matching, clearances to the chainstay, lateral balance, and making sure I have the correct extractor (the price of becoming free of fine-tuning cotter pins). But once you have found the spindle which matches the crank to the bike, you’re set for several more decades.