Bicycle Mechanics - Cotter pin -crank rubbing frame - convert to cotterless?
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02-25-09, 12:14 PM
I have just bought a 1957 raleigh something or other (!) and have a few queries about the whole crank set up. I have confirmed that it has cotter pins but have a few concerns;
1. The crank arm on the chain side is ever so slightly rubbing against the frame (chainstay? not sure what that bit is called but it runs from the bottom bracket to the drop out, parallel to the ground) but the bottom bracket seems to be rock solid. As it is rock solid I don't want to go messing about with the whole thing if it means a big job - which leads on to my second question;
2. With these cotterless cranks is it possible to whip the whole lot out and replace with a modern bottom bracket and chainset. Is this possible?
Sorry, know I must sound like a complete idiot - don't know much about bikes!
02-25-09, 12:20 PM
1. If the BB has an adjustable chainline, you could simply move it more outward.
2. If you can find a BB with the same threading as your BB shell(you probably can), absolutely.
02-25-09, 02:37 PM
As for 2)-
You can do one of a number of things, but you'll have the problem that modern BB's take 24 TPI threading and yours is likely to be 26 TPI. You can tap the shell to 24 TPI, or buy a Phil Wood BB and 26 TPI cups ($). Or do what I did and grind away all but 3 rows of threading on a modern cartridge BB (3 rows of 24 TPI will screw into 26 TPI shell just fine) and use it that way.
02-25-09, 02:39 PM
Take a look on the non-drive side where the crank gets closest to the frame... is it considerably further away than the drive side? If it is then it is possible that the bottom bracket spindle was removed and reversed resulting in poor spacing of the arms. You could take the spindle out againa nd flip it and see if it improves.
It is also possible that the bike was dropped or hit by a car or something just badly enough to bend the cranks arm in by a few cm. If this is the case then you shoudl just replace it.
Old ralieghs have different bb threading than modern bikes. Check www.sheldonbrown.com for details... I think the raleighs have 24tpi threads and modern bikes have 26tpi... close but not compatible. According to Sheldon Brown, the only (or one of very few) company making 24tpi bottom brackets is Phil Wood, and they almost certainly cost more than another 1957 raleigh.
You can probably find a new spindle with square tapers, though, to use with your existing bttom braket cups and a modern square-taper cotterless cranks. Again, sheldon brown has the whole story.
02-25-09, 02:52 PM
Is there enough room on the spindle to slide the crank arm out slightly and then reset it with the into position with the cotter pin in a way that clears the chainstay?
... I have just bought a 1957 raleigh something or other (!) and have a few queries about the whole crank set up. I have confirmed that it has cotter pins but have a few concerns ...
1. Before you go upgrading a 1957 Raleigh, tell us more about what model it is; some models are too nice to upgrade!
2. If the crank is rubbing the frame, something is very wrong. I hope it's just what LarDasse74 said; if it's not that, then possibly your whole frame is bent or something like that, in which case replacing the crank is not going to help.
3. Post your bike and questions about it in the Classic and Vintage forum... with pictures. Everyone loves pictures.
4. Good luck!
02-26-09, 09:26 AM
You probably just need to replace the cotters. Riding with loos cotters ruins them. Find a bike shop with a mechanic old enough to know to do it.
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