Removing cranks after...

[661-Pete]

This is a story with a happy ending.

I've known for years that my shopper (actually a superannuated tourer on a 531 frame) needs a complete new drive train. The chain is so stretched that it hardly deserves to be called a chain, and as for the chainset....

I'd more or less given up on getting the (taper) cranks off, because the last time I tried, using a cheapo extractor (probably from H***ords) the extractor threads stripped clean off and the cranks wouldn't budge. I assumed I'd had it, would need to take a hacksaw to the wretched things.

Today I summoned up the pluck to have another go, this time with a more recently-bought Park Tools extractor. It needed plenty of welly (literally), but after a lot of f***ing and blinding the cranks came loose! And I still have ten fingers, at last count.

I say, hats off to Park Tools!

 

[Manonabike]

Well done!!!!

Time to check the BB I'd say and good luck with removing that which can be ever harder....

 

[661-Pete]

Well done!!!!

Time to check the BB I'd say and good luck with removing that which can be ever harder....

That's staying exactly where it is! It still runs fine (well, good enough for shopping anyway) and will outlast the rest of the bike. Second reason: I araldited it in many years ago, after the thread on the B/B shell stripped (stripped threads seem to be a speciality of mine ). No, it was only the chainset that was a matter of extreme urgency: when the chain no longer stays put on it.....

 

[02GF74]

you were lucky the threads in the cranks did not strip off (I assume they are aluminium alloy)

 

[airbrake]

I bought a second-hand road bike a few years ago that had cranks firmly stuck on the tapers. It had been built in 1991 and then put into a damp shed and not ridden since. I wound in the extractor bolt, and sure enough they wouldn't budge.

I sprayed some thin oil around the back of the cranks (it can usually wick in a little on the corners of the taper), then I wiped off the excess. I then got a hairdrier and got the crank nice and hot (couldn't touch it). I wouldn't use an electric 'heat gun' though.

I tightened the extractor a little more, then allowed the crank to cool down. I went through this expansion - tighten extractor - contraction process about 4 times and the crank came loose - same for the other side.

A faster way is to put your bike in a high gear, then set your extractor nice and tight. Lean the bike at a slight angle against a wall (protect any rubbing points unless it's a beater). Get someone to hold the bars steady while you put a foot on the pedal. Now put your full weight onto the pedal and gently 'bounce' on it. Sometimes you might hear a slight creak. Tighten the extractor and repeat. Usually it will start to come loose pretty quickly.

Another way - take off the crank bolts and ride up and down the street a few times

 

[asterix]

That's staying exactly where it is! It still runs fine (well, good enough for shopping anyway) and will outlast the rest of the bike. Second reason: I araldited it in many years ago, after the thread on the B/B shell stripped (stripped threads seem to be a speciality of mine ). No, it was only the chainset that was a matter of extreme urgency: when the chain no longer stays put on it.....

When I removed a cup and cone BB after that sort of time I found the grease had turned to putty!

It is sometimes hard to get the threads in right on a BB, esp. on a cheapo, if you have the slightest doubt don't force anything, start again!