Farewell Cottered Cranks

Don't follow you C.B. All I know is that hot water was gentle enough to allow the cranks to expand enough to drop off with three gentle hits, whereas before I was going at them like a miaow-miaow head at a scrotum.

you said for cranks that arnt good for anything else as though the would be write off afterwards, hot water is much better than blow torch

The trick is to use a product like mollyslip when fitting taper fits, the thin coating should allow for easier disassembly. The angle grinder is a good call, I have found the stainless steel discs to be really good.

Hot water can be better than a blowtorch as water has a very high specific heat capacity. Whereas air / the flame of a blowtorch hasn't.

^ I suppose it could be better in certain scenarios. If the blowtorch is two feet away from the part, for example.

But otherwise a blowtorch will get something much hotter, much faster and in a much more concentrated area.

I have one of these for such occasions

Please wait
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Hasn't failed me yet although applying heat helps if it's an alloy crank.

i new something like this must exist i started thinking up plans for such a device it looked very similar in my head

You can also use a fork-type balljoint splitter.

The fork bit goes between the BB and the cranks. Then whack the end with a mallet to act as a wedge. You can pick up short versions of these for about a fiver from a motor factor/Halfords, or longer versions (more useful on a bike to get past the chainring) for a little bit more.

Been there. What you have to do is to go back in time and grease the tapers, like Shimano tell you not to do.

controversial

I've always greased tapers.. VERY VERY lightly. Literally like a wipe with a greasy finger.

http://en.wikipedia.org/wiki/Bottom_bracket#Greasing_of_tapered_cranks

http://sheldonbrown.com/brandt/installing-cranks.html

The admonition not to grease the spindle finds life mainly in the bicycle trade. When I discussed the "dry assembly" rule with crank manufacturers, I discovered that they had warranty claims from customers who split cranks. However, cranks cannot be split by overtightening them. This can be proven by attemting to do so. An M8x1 bolt is not strong enough to split a major brand crank.

i grease the tapers then wipe it off again with an old dirty rag

sheldon says grease, so we shall grease

Blow torch method has failed me :( , I've just broken a park crank puller!

^ that tool is a piece of shit. Ive destroyed 2 of them.

When my cranks siezed irreversibly, I had mine put on a mechanics stand. I held the down/seat tubes while the mechanic smashed it from the other side with a flogging hammer and a chisel.

Worked.

Dremel and small cutting disc is easier to control than an angle grinder I think.

PS, I do have other tools, I just like the dremel.....

I'm gonna try the riding around with no crank bolts method for a week or so. Btw dremmels are for poofs!

Dremel and small cutting disc is easier to control than an angle grinder I think.

PS, I brush my teeth with the dremel.....

ftfy

Well my wee drama continues. Turns out the sales asistant at endinburgh bikes sold me the wrong park crank puller (I never knew there was 2 types), resulting in stripped threads on the drive side :( Going to get me one of those ball joint splitters tonight. Pretty pissed off with the wee f***!

My bike and I just had our first fight. It didn't want to let go of it's cranks. I insisted, but no manner of pulling, leveraging, hammering or WD40ing would make them budge.

They're only alu, seized onto a hollow spindle - but it's one hell of an interference fit. I might introduce bike to hacksaw tomorrow evening and see how they get along.

Update:

Round II was much more productive. Ball joint splitter seemed to loosen the crank, aided by lots of WD40. It still wouldn't just pop off, but it was just a case of wiggling the crank until it worked itss way off the spindle completely. Hope this helps someone else!

As for the BB, it had six notches on either side and tapping one of the notches with a chisel (I only have an 8 notch tool) made the whole BB spin inside the shell. I managed to wedge it on one side against a crank and then undo the other side by hand. Once the cap had been removed on one side the BB slid out.

Time to hunt for a new threadless BB.

Ok; anyone got one of the above tools for removing a crank with ruined threads that I can borrow soon? I am in N16 but will travel to collect. Thanks

What ya want?

A puller or a ball joint splitter?

You about tomorrow? As I'll be in nearby working on a bike.