lost thread on crank arm

[Dirtyhanz]

Hi i have got to take a chainset off a bike i have got the chainset side off come to take off the other side and find some body before me as had a wright go at it the thread is all shot what do i do.

 

[lpretro1]

If you have an old fashinoned crank puller then you could try that - the one that has arms that fit behind the head of the crank arm and then you tighten a bolt on the front to push it off. Otherwise a couple of solutions - Neither is very good.You could try heating it up - it may then just drop off. Risks damaging paintwork. Otherwise you'll have to cut it off . If not reusing bottom bracket then just cut through bb axle. If you need the bb then you'll need to make a couple of cuts carefully through the crank arm - make the in a wedge shape and then you should be able to knock it out an crank will come off.

 

[Star Strider]

The risky solution if you are binning the crank and you don't have a 3 arm puller is to go for pootle round the block with the crank bolt removed.

 

[sidevalve]

OK, risky solution [assuming you can't beg borrow or [maybe not] steal a basic puller [try a local garage or even DIY car car freak] if we are talkig about a square taper put a VERY heavy hammer on one side of the crank and hit the other side with another hammer [ie across the flats of the taper] 1 or 2 good solid blows should do it [if you're lucky]. You may damage or crack the crank arm so this is a last resort.

 

[eck]

A mate made himself a sort of two-pronged chisel, a bit like a tuning fork, for this job. Slot its prongs behind the crank against the BB, and tap it gently give it a whack. You will easily guess how I know it works.

 

[Dirtyhanz]

They where quick replys thank you
I found a Joe Waugh frame in a skip went and knocked on the door and the guy said i coild have it.
Its a 531c frame and forks its got cinelli bars and stem on it campag headstet and campag brakes and a campag chainset and they all look great it even had look pedals on as well.
the frame as got a bit of a dent in the top tube so i am stripping it down go to get new top tube fitted think this is about 100pound job get it sand blasted and sprayed at c and g thats about another 100 pounds then it should look like a new frame for about 200 pounds with a few extras.

 

[HovR]

As someone said above, if the bike is rideable you could ride it around the block a few times (with the crank bolt off) until it loosens up, at which point you should be able to pull it off. The only issue with this is that if you ride it too far after it has loosened up then you can damage the square taper permanently causing it to not fit back on properly.

 

[Dirtyhanz]

i can not take the bike for a ride its not ridable no wheels or gears i have it in a repair stand would it make any diffrence just to keep turning by hand
Thanks for the help

 

[sidevalve]

Very nice frame. Could be well worth buying a puller to make sure you don't damage it. As it's only going to be a one off job [unless you make a habit of finding good frames, in which case post one up to me !] you could get a cheap one for under a tenner.

 

[Dirtyhanz]

Got it of a little bit of heat two maybe three blows from a big hammer no damage to frame or the bottom bracket seat post next thanks for all the tips.

 

[GIOS]

One of my ex-colleagues had his cranks removed with liquid nitrogen.

 

[Richard Broomhead]

Hi Dirtyhanz,

Just stumbled across your for sale thread, but I evidently haven't posted enough to be allowed to reply tin that thread.

Is the Raleigh Randonneur still available, and is that 52cm size you quoted C-T or C-C?

If you could get in touch I'd appreciate it. email is in the form: surname.firstname@yahoo.co.uk

Thanks
Richard Broomhead

 

[andrew_s]

A mate made himself a sort of two-pronged chisel, a bit like a tuning fork, for this job. Slot its prongs behind the crank against the BB, and tap it gently give it a whack. You will easily guess how I know it works.

You can buy those fairly cheaply from car tool shops. A ball-joint separator
Two in opposition may work better than one.

 

[Wooliferkins]

This is the tool somebody somewhere must own one http://www.dotbike.com/p/14008/Unior-Taper-Thread-Crank-Puller

 

[screenman]

One of my ex-colleagues had his cranks removed with liquid nitrogen.

How? the cold would make the crank shrink, unless of course they could just freeze the spindle, smacks of mate of a mate to me.