Cotter pins: Is there a right way round?

[Jonny69]

As title. With cottered cranks, is there a right way and a wrong way to insert the cotter pins? I'm guessing it's flat-to-flat, but if the crank arm on the drive side is pointing horizontally forward, is it better to insert the cotter pin from above or from underneath?

 

[Some Guy]

I asked similar a while back. KeithGloss(?) kindly told me it was, cranks pointing back, thread and nut at the bottom (when fitted), was UK way. Although Americans do it thread and bolt on top, because they didn't use cycle clips. Or something along those lines.

Although it could've been other way around, don't think so tho.

 

[Jonny69]

Makes sense. My RSW has the nuts on the top when the pedal is forward and it drives me crazy because my flares get tangled up on them

Ok, so crank back, insert from the top...

 

[Midlife]

Line up the crank with the chainstay and insert the cotterpin......flat to flat

Just don't over-file the beggers !!

Shaun

 

[Spokesmann]

I put em in any way up, as long as the flats are lined up!

 

[keithglos]

All British bike manufacturers fitted cotter pins as SomeGuy reminds us, but I can not see a mechanical reason for this, crank forward, cotter pin up. In the 1950's I bought nickel plated cotters for about £2.50 a gross (144), and gave the cyclo adjustable cam tool plenty of use.
Also the 2 hammer trick, to remove a resisting cotter. One fairly light on the cotter pin, and another slightly heavier to hit the first hammer. Rapid but firm hits, ususlly worked, this keeps fingers out of the way, and the aim does not need to be so accurate. Helps if you support the bottom bracket.

 

[Jonny69]

Cool, cheers.

I was always taught not to hit two hammers together. The hardened faces can splinter and send shards of metal flying out. I've always used a punch on the stubborn ones, but I've got a good aim

 

[Spokesmann]

Cool, cheers.

I was always taught not to hit two hammers together. The hardened faces can splinter and send shards of metal flying out. I've always used a punch on the stubborn ones, but I've got a good aim

Me too!

For really stubborn cotters Id used a block of hardwood to protect the thread, failing that if they wouldn't budge hit em hard with a big hammer and replace the damn things!

I alway put a dab of grease on mine which helps when you do need to free them again!

 

[poweredbypies]

Cool, cheers.

I was always taught not to hit two hammers together. The hardened faces can splinter and send shards of metal flying out. I've always used a punch on the stubborn ones, but I've got a good aim

Mythbusters did this one all they managed to do was bend the hammers shafts. Tried with estwing hammers n all.

 

[keithglos]

More chance of a bit flying off the punch. Hammer head should not be brittle, never seen one shatter, tough but fileable.