N00b question - cottered to cotterless conversion

[stug808]

Hi, I'm new to the forums and I have a mid 70's Claud Butler Velox S and two 5 speed Peugeots, one late 70's and one late 60's or early 70's. The Peugeots are just gas pipe type fair while the Claud is a nicer spec although still a budget line with 531 straight gauge tubing and Campy Valentino (marked as Velox on this bike) groupset, but it only cost £60 and is a good looker and came with a very good condition Brooks B17.

Anyway, my question is: The Claud has a very heavy Williams double front crankest (although has a fluted crank, so must save 0.005 grams there!) with a cottered setup. I'd like to change this to a alloy cotterless setup. So once I get a square taper crankset, can I just change the spindle to an ISO (or whatever) one or do I have to replace the whole bottom bracket?

 

[Elysarian]

If you can get a spindle the right length - both bearing spacing and drive side axle length - (and the rest of the BB is in good condition) then a spindle transplant would do the job while leaving the bike looking somewhat more authentic than fitting a cartridge in there.

Cost-wise it'd likely be cheaper to pick up a lower-end Shimano sealed unit (UN54 or similar) though.

 

[lewisfoto]

Replacing just the spindle is actually kind of dicey. Different manufacturers have very different designs and very few are totally interchangeable. Besides cup and bearing BBs from the 70s are plentiful and cheap not to mention a more reliable build if the whole BB is made to work together.

 

[Tel]

I could well be interested in the Williams chainset and bb set when you replace it

 

[stug808]

So if the threads on the BB are common (ISO, I imagine they would be) it would be fairly easy to swap it all over and fit a tapered crankset? There is some play in the BB (pedals rock side to side very slightly) so a replacement would sort that out.

I'll keep you in mind Tel when I do the conversion, I would have to find a suitable alloy crankset which still has a vintage look (stronglight type of cranks) but these seem to be the most in demand and expensive at the moment! I just remembered that it's not just the weight saving I'm after, but also to get away from the infuriating habit of the chain falling between the chainrings when shifting between gears (too narrow a chain for the rings?).

 

[Tel]

The bb is adjustable so you can adjust the play out.

Yes any English thread bb should fit straight in.

Stronglight would be ideal.

 

[DaveB1]

I've also heard tell that for non-typical BB sizes (Raleigh, French), people have used velo orange's thread less bottom brackets as well...

 

[Midlife]

http://www.ebay.co.uk/itm/Vintage-Bicyc ... 4ac472837f

The above is the sort of thing we put on 70's bikes when people wanted an alloy cotterless chainset.. Red dust caps and all

Shaun