Cotter pins

[Chris S]

I will probably have to renew the cotter pins the next time that I take the cranks of my 1970's Raleigh.

I've noticed on ebay that there are three sizes: 9mm, 9.3mm and 9.5mm.

Does anybody know what size I should use? My bike has a chainring similar to the one in the picture, instead of one with the usual Raleigh herons.

 

[Ian H]

Sit yourself down and have a read: https://www.sheldonbrown.com/cotters.html

 

[midlife]

They are pretty cheap so maybe just buy some and try them ?

https://bankruptbikeparts.co.uk/pro...-pins-9-5mm-milled-or-unmilled-1-pair-new-nos

 

[tyred]

For a Raleigh it will be 9.5mm (which are 3/8").

Most continental made bikes use 9 mm whereas British made bikes are 3/8".

 

[Gwylan]

How I love the things I can learn in this forum.

 

[Chris S]

They are pretty cheap so maybe just buy some and try them ?

https://bankruptbikeparts.co.uk/pro...-pins-9-5mm-milled-or-unmilled-1-pair-new-nos

Three different sizes (9, 9.3 and 9.5mm) would come to £9. I'd have wasted £6 on cotter pins that I would never use.

 

[tyred]

I have no idea what 9.3 would fit. I'd say they are 3/8" and someone made a dog's dinner of measuring them.

 

[Gunk]

Use a wooden block with a large hole drilled in it to support the chainset, it’s much easier to hammer the pin in using this method, otherwise all the energy is transferred to the frame.

 

[tyred]

They need to be hammered or pressed in again too. The nut only holds them in place. The thread is nowhere near strong enough to pull the pin into place.