Help with stuck crank arms

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12/13/2019 5:28 AM
Edited Date/Time: 12/13/2019 5:29 AM

What's up fella's? It's been a while! Hope everyone is doing well!

I need some help. Just got a new frame and I had some Merritt battle cranks laying around that I wanna try out.

Problem is, I can't get the damn arms off the spindle. I attached the arms to the spindle to keep everything together but can't get them off now.

I've been hitting them with a puller to no avail. Let them sit overnight in WD-40. Still won't budge...

What's the best way to go about this? Should I try to clamp the spindle down and just keep wacking at the puller?

Maybe try heating them up a bit?

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12/13/2019 5:42 AM

Get a bolt from the hardware store that matches the spindle threads. Thread it in as much as possible without tightening up against the crank and then hammer the head of the bolt. You want as much thread contact as possible in the spindle, to avoid damaging the threads.

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12/13/2019 6:08 AM

I have a puller bolt that I'm hitting but they are not moving.

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12/13/2019 6:25 AM
Edited Date/Time: 12/13/2019 7:10 AM

dead goon wrote:

I have a puller bolt that I'm hitting but they are not moving.

Are you hitting with the crank supported against a vise or something, or are you hitting it while just holding it?

If it's the latter and you have access to a vise, put the crank in the vise in such a way that the spindle goes down between the jaws and the spindle boss rests on top of them, tighten it up until it just barely touches the spindle and then try hammering.

If it's the former, it may require a little heat differential. Put the crank in a freezer for an hour or 2, then, heat the spindle boss with a torch and try hammering on the bolt again. The aim of this is to create a large difference in temperature between the crank and spindle, which should result in a much looser fit. You shouldn't need to get it very hot as steel expands around 0.07% per 100°F, which may not seem like much but it's quite a large amount relative to the tolerance of a normal pressfit. Excessive heat should be avoided as it can change the properties of the steel.

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My Sunday Soundwave V3 Build
Insta: @p.gibbons

"You can't educate pork"
- grumpySteve

"Life should not be a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside in a cloud of smoke, thoroughly used up, totally worn out, and loudly proclaiming "Wow! What a Ride!""
- Hunter S. Thompson

12/13/2019 6:49 AM

p1p1092 wrote:

Are you hitting with the crank supported against a vise or something, or are you hitting it while just holding it?

If it's the latter and you have access to a vise, put the crank in the vise in such a way that the spindle goes down between the jaws and the spindle boss rests on top of them, tighten it up until it just barely touches the spindle and then try hammering.

If it's the former, it may require a little heat differential. Put the crank in a freezer for an hour or 2, then, heat the spindle boss with a torch and try hammering on the bolt again. The aim of this is to create a large difference in temperature between the crank and spindle, which should result in a much looser fit. You shouldn't need to get it very hot as steel expands around 0.07% per 100°F, which may not seem like much but it's quite a large amount relative to the tolerance of a normal pressfit. Excessive heat should be avoided as it can change the properties of the steel.

At home last night I was just hitting it against the ground. I brought them into work today to see if we have a clamp here.

I'll also try putting them in the freezer for a bit. Thanks!

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12/13/2019 12:15 PM

Problem solved. Co-worker knocked 'em out with a 10 lbs. hammer

Thanks for your input, p1p.

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