Cottered crank/BB problem

leelovesbikestoo · Feb 16, 2011

Hi all

I have an old 50s Hercules Balmoral 'gentlemans bike' as a city runaround which has developed a bit of a problem.

The non-drive cottered crank is binding against the BB shell after a few miles (which is all I do per trip, anyway). I have removed the cotter pin to make sure the crank is sitting in the right place, which it is, and also slipped on some resin washers between crank and shell to ease the friction. The washers are since wearing thin and the friction is returning.

Can anyone suggest a way around this, short of replacing the BB?

leelovesbikestoo · Apr 19, 2011

... anyone?

Simon Daw · Apr 19, 2011

I think the "short of replacing the BB" bit is probably the sticking point! :?

Seriously, though. I presume you mean that the crank is binding on the cup, not the shell (which is part of the frame)? If that's the case, is there any chance that a different cup might help? Different cups are different thicknesses, and if your cup seems to protrude quite a bit (the old Stronglight cups did, for example) then a replacement might help. Unfortunately, it's likely to involve quite a bit of trial and error, though.

BerthaPog · Apr 19, 2011

If the binding gets worse as you're riding that suggests that the BB cup is "loose" and unscrewing? Do you have a lock ring on the non-drive side?

Cottered crank/BB problem

leelovesbikestoo

Old School Hero

leelovesbikestoo

Old School Hero

Simon Daw

Dirt Disciple

BerthaPog

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