Welcom Back Cottered...

[handyandy1100]

Picked up this old Ertl trike to fix up for my grandson. He's only 14 months so I have plenty of time to get it ready. LOL

I need some help with the cottered cranks. One pin is good and snug even though the nut doesn't tighten as the threads are stripped. The other pin is loose and the crank wobbles. It doesn't look like the one that's tight, so I figure it's not original. Who knows, maybe neither one is original.
Never worked on cottered cranks before. Is there any special trick to picking out the right pins?

 

[Starnger]

Them cottered are always a pain
I am not even sure there are many standards out there. Just get a normal pin and if it doesn't fit then well, you've tried, just weld it on

 

[clamdigger]

The bicycle guru says it best ; https://sheldonbrown.com/cotters.html

 

[MattiThundrrr]

Just get a normal pin and if it doesn't fit then well, you've tried, just weld it on

A quote from the manual, probably

 

[bunnyman666]

The bicycle guru says it best ; https://sheldonbrown.com/cotters.html

If anyone is the best resource for all things bicycle, it’s ol’ Sheldon.

 

[bunnyman666]

Picked up this old Ertl trike to fix up for my grandson. He's only 14 months so I have plenty of time to get it ready. LOL
View attachment 158281
I need some help with the cottered cranks. One pin is good and snug even though the nut doesn't tighten as the threads are stripped. The other pin is loose and the crank wobbles. It doesn't look like the one that's tight, so I figure it's not original. Who knows, maybe neither one is original.
Never worked on cottered cranks before. Is there any special trick to picking out the right pins?
View attachment 158278View attachment 158279

It’s a cool trike. But I take issue with that song playing in my head on endless loop!
J/K

 

[Grant]

Those pins look way to small.

 

[Grant]

I have 2 bikes that came with cottered cranks. Was able to get the pins out by hitting them with a hammer repeatedly pretty hard.

Both have square taper cranks because the ride quality with cottered cranks is really wonky as the cranks are never perfectly aligned.

 

[ifitsfreeitsforme]

good luck with that. My local bike shop doesn't stock cotters any more, but informed me that they come in assorted sizes (something I was not aware of).

and thanks for the Welcome Back Cotter theme song ear bug. ugh.

 

[deorman]

Cotter crank? RUN AWAY!!!

Seriously though, the only suggestion I have is get the fattest replacement pins you can find, if they're too big you can grind them down. Once you have some fitted, don't try to tighten them with the nuts, drive them in and then snug the nuts to keep them in place. A drop of blue Loctite on the threads wouldn't hurt.

 

[Karate Chicken Industries]

and thanks for the Welcome Back Cotter theme song ear bug. ugh.

At least it's John Sebastian. Earworm this then:

 

[bunnyman666]

At least it's John Sebastian. Earworm this then:

Man, that miming was the worst I have ever seen LOL

 

[handyandy1100]

Thanks guys. One pin seems to be the right size and is tight. I found an acorn nut that fit it to dress it up. The other, the one that almost goes all the way through I drove in so the crank was tight then added a bunch of washers so the nut tightened up.

 

[handyandy1100]

I have 2 bikes that came with cottered cranks. Was able to get the pins out by hitting them with a hammer repeatedly pretty hard.

Both have square taper cranks because the ride quality with cottered cranks is really wonky as the cranks are never perfectly aligned.

Not sure how to do that in this case. Probably have to machine a whole new axle.