Crank question!

[BoyBurning]

Hi all,

Can I use a driveside arm to replace a broken non-driveside?

Don't see it should be a problem if I remove the spider. Might have to machine down the surplus alloy which retained the spider but other than that...

Has anyone done this, know if it works or has a good reason for me not to do this?

Cheers!

NB - I'm aware the pedal threads would the the wrong way...!

 

[B3]

I cant see why not, the only thing i'd do is loctite the pedal in place just in case i decides it wants to "unwind" itself. The important bits, taper/pedal thread will both be symetrical about the centre of the bike.

 

[pete_mcc]

Surely the only problem would be as B3 said that the pedal would unwind itself as the thread is reversed to the direction it wants to go in. I remember a courier in London who had a single speed set in reverse with the drive on the other side (no other reason than to look different) and is pedal was always falling off (and he had to weld the rear cog lock ring on as it kept on coming off). Can't you find another crank arm as I would have thought that'd be cheaper than having to find another right hand pedal? What cranks are they?

 

[BoyBurning]

Cooks RSR...

Non driveside has a hairline crack.

Can't find a replacement but have found a driveside which is minus the spider. Just wondered if I could use that as a replacement but am aware of the pedal issue and don't want to be falling off every time I go for a ride...

 

[B3]

I've got a set of middleburns with the same problem, may try tig and redress the taper.

 

[BoyBurning]

I've thought about that but think it's a bit risky no? So much torque going through the crank at the taper end that it wouldn't last for long?

 

[Sam R]

why don't you just re-tap the thread and use a helicoil insert?

 

[B3]

I've thought about that but think it's a bit risky no? So much torque going through the crank at the taper end that it wouldn't last for long?

It probably depends on how big your crack is :? and will be a suck it and see exercise, if goes again then nothings lost. Depends on far the crack has spread too.

There's that Australian company that do all sorts of frame repairs that you would think were impossible, they may be able to help. Can't remember the site off hand, but i think i came across it on this forum.

 

[B3]

The other option is to solid model the cranks and do a "retrobike" limited edition set of cranks

Did someone say group buy?

 

[pete_mcc]

That's a bugger as I have a NOS non drive side e-crank arm (and a complete NOS set of RSRs, but thats another story, would take a fair bit of cash to pull them out of my collection), or a set of MRC steely dans, but one of them has a hairline crack and I can't remember which one off hand...