Fitting Cotter Pins, direction??

Some Guy

Retro Guru
Excuse my ignorance, it's my 1st time dealing with cottered chainsets.

I've read Sheldon, but my poor little brain is getting confused by this whole direction of the cotter pin thing.

To put it simply, in a way I understand. If I'm viewing the bike from the chainring side, an the chainring crank arm points down and the other crank arm points up. Should both the cotter pin bolts be facing towards the rear of the bike?

Thanks in advance for any help.

Mark.
 
Ok, You Tubed it this morning an seeing a video makes it clearer! :)

With the cranks horizontal and with the chainring crank pointing backwards. Chainring side bolt facing upwards and non chainring side bolt facing down. Seems to be the way. Although refering back to Sheldon it doesn't really matter as long as they're different.

Now going to use a file, old steel seat post and a hammer. Fingers crossed!
 
Some Guy":fsi7nks0 said:
refering back to Sheldon it doesn't really matter as long as they're different.
yeah, thats right, else you end up with ten to three (clock sense) cranks, ie not in line.
 
Thanks for the reply appreciated and reassured!

One side done and 2nd just about to go on. Looking forward to the test-ride shortly! :)

Mark
 
The standard direction all British manufacturers used was opposite to yours. With the crank facing the rear the cotter always went in downwards. I can't see any real engineering difference, but the Americans decided to use the opposite. The only reason I have seen for this is so that their clothing does not catch on the nut. We used to have trouser clips.

Also they are guilty of many sins. Clincher tyres were beaded edge which the UK abandoned about 1900, really wired-on.
European wheel builders almost always had the spokes from the inside of the flange going in opposite directions. To make lacing the wheel more difficult, they decided in the US that they would face the same way.
 
keithglos":1m9yio7r said:
The standard direction all British manufacturers used was opposite to yours. With the crank facing the rear the cotter always went in downwards. I can't see any real engineering difference, but the Americans decided to use the opposite. The only reason I have seen for this is so that their clothing does not catch on the nut. We used to have trouser clips.

Also they are guilty of many sins. Clincher tyres were beaded edge which the UK abandoned about 1900, really wired-on.
European wheel builders almost always had the spokes from the inside of the flange going in opposite directions. To make lacing the wheel more difficult, they decided in the US that they would face the same way.

Funnily enough it was an American YouTube video that showed the way I described originally. Although when I came to putting the pins in my Williams crankset they seemed to fit best as you described, so I'm happy to have done in it the British way!
 
I've only had to deal with the cotters on one of my bikes. Only one probably very stupid question:

Should the flat side of the cotter pin be against the flat on the axle?
 
Yes.

You should tap them in gently, and file the flat to fit, keeping the same angle. We used to get them with smaller flats for cranks that had stretched

Finally tap in a bit more firmly, better to support the underside of the crank or bottom bracket.
I always used 2 hammers, not very heavy (4 to 8 ounce), rest one on the cotter, and hit the top of it with the other. This keeps your fingers out of it, and improves the aim.
I also had a cyclo long handle tool which squeezed them in, adjusted on a cam.

British size was 3/8 inch, but probably now9.5mm, continental 9mm.
 
gotta laugh here (at me)
I didnt know there were different sizes. Last time I had a cottered chainset, just bought a cotter pin (??size) put it in by hand, flats against the axle. got a 7lb lump hammer, hit it hard as I could a few times. Then put the nut and washer on, screwed it on semi hard with a spanner, sit on bike and put weight on both pedals to bed it all in, more big bashes with said lump hammer and tighten nut up hard. Job done!
What a butcher! :oops:
having said that, the bikes were only clunkers, no concours restoration jobs.
 
Jonny69":3983hc3z said:
I've only had to deal with the cotters on one of my bikes. Only one probably very stupid question:

Should the flat side of the cotter pin be against the flat on the axle?

Yes!

There is a slot in the bb spindle for the cotter to wedge against.
 
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