stuck pedal

[ericonabike]

Ever read Zen and the Art of Motorcycle Maintenance? In it he describes 'gumption traps' where you go to do something real simple that turns out to be a nightmare that sucks the confidence from you. My current gumption trap is a stick pedal on my Dahon Presto Lite. I want to change the pedals, simple enough, but was disappointed to see there were no 'flats' to put a spanner . Instead there was just an allen bolt. Suspected it might not be straightforward....

Attacked the left hand [non drive] pedal, mentally reassuring myself a dozen time that yes, it has a reversed thread. Tried in situ - no movement. Removed the crank, put the allen key in a vice and used the crank as a lever. No movement. And one snapped allen key.Soaked in penetrating oil. No movement. Immersed end of crank in boiling water and tried again. No movement. I am putting as much weight as I dare into the process, but am scared of turning a hex into a circle. I suspect that the problem lies in the crank being alloy and the bolt steel, as they seem to have bonded chemically! Am now officially out of gumption - anyone got any ideas?

[Mick F]

I would have done as you have done, but perhaps heated the crank more than boiling water can do. I'd have played my blowlamp on the crank a bit.

Do you want the pedal?
Can you get the spindle into a vice and grip it VERY tightly instead of using an Allen key?

[Brucey]

if the pedal is for the bin, I'd dismantle the pedal, grind a couple of flats onto the spindle then use a big spanner or a bench vice to shift it.

I have had to use a blowtorch and penetrating oil and a big spanner before now to shift pedals that are really bad, on other people's bikes. My pedals go into the crank with a load of copper-ease on them, and this means they don't seize in position.

BTW I make a point of not buying pedals with no spanner flats on them because it causes so much trouble when time comes to remove them.

A word of warning; if the crank goes over ~180 to 200C for any length of time it may alter the heat treatment condition of the crank.

In a gumption trap I usually find that I need more gumption and/or more tools. Tools you can buy, but gumption is a rather more elusive quantity.

cheers

[ericonabike]

Thanks both. The pedals weren't intended to be scrapped, but I think I can see the necessity to do so if they're to be replaced. Grinding/filing flats then putting it in the vice just feels right, whereas using an Allen key seems a lost cause. Will make a point if checking removal design of any future pedal purchases, but these were o/e

[Valbrona]

You need like a breaker bar thing and a hex bit. A regular hex wrench is not worth trying.

[PJ520]

Brucey's grinding flats solution is the way to go. I had this happen to me and even tried an impact driver on the hex socket. Went to all the trouble of buying a set of 3/8 drive allen sockets, didn't do bit of good. My LBS bloke, been in business 40+ years, said he'd actually had had one defeat him in all that time and had to replace the crank arm; he thought mine was going to be a second but it came off grudgingly with heat and grinded flats. I don't think wrench flats that come with the pedal (which mine didn't have) would have been much use. My guess is that if they are that stuck any pedal wrench you try will just open up. I notice that now Shimano SPDs have a 6mm socket rather than 8mm making the grease all the more important, but my new ones do have flats.

FWIW In the past I have removed pedals with a multitool Allen wrench by standing on the pedal and pushing down with my other foot on the wrench

[Brucey]

You need like a breaker bar thing and a hex bit. A regular hex wrench is not worth trying.

if you use a socket type allen key drive this has the advantage that you can put a long lever on it. However it isn't actually any stronger than a decent quality allen key is; they use the same steel for each.

I notice that now Shimano SPDs have a 6mm socket rather than 8mm making the grease all the more important, but my new ones do have flats....

most SPDs have always had flats. Most (but not all) that have flats also have a 6mm allen key fitting, and they have always been like that. A few models (mostly the posher i.e. lighter, more expensive double-sided models for mountain bikes) have in recent years come with a larger allen key fitting and this is the only means of fitting and removing the pedal. These posh spindles have also broken more than they should have, so unless you are worried about the last 30g weight then I recommend sticking with the more basic models of SPD which also have sensible pedal flats.

....Grinding/filing flats then putting it in the vice just feels right, whereas using an Allen key seems a lost cause.....

It can't hurt to use both at the same time? BTW pedal spindles are very hard; you won't (easily certainly, probably at all) be able to file flats on them. Hence you will need to grind instead.

cheers

[ericonabike]

Update - success, thanks to advice from here. Dismantled the left hand pedal, filed flats on axle [not too difficult, perhaps cheap steel used] heated the thing to near melting point on gas stove, clamped axle in vice and put 14 stones [approx] onto pulling on the crank. At last, with a distinct groan, it shifted! Then went on to right hand pedal. Thought I'd try clamping an allen hex piece [not allen key this time] in the vice just to see if I could avoid the filing process, having first dismantling it and heating it up. No chance. So - same process for right hand pedal - but not movement. Que? Then I remembered the gumption trap. Flushed with success from the left hand pedal, I'd been pulling the right hand crank in the same direction....

Flushed with embarrassment, tried again, and the crank gave up its struggle. Have now fitted the replacement pedals [with oodles of copper slip] and it's good to go. But what a farce! Moral of the story, for me, is never ever buy pedals that have only allen key fixing. PERHAPS those that use 8 rather than 6mm fixings would stand up to the effort needed to shift them, but I rather doubt it. Flats rule for me from hereon in.

[Brucey]

good work!

cheers

[Mick F]

Excellent news.
Well done!

Moral of the story is to copper grease the threads, and to take the pedals off periodically.

[Kenn]

After a bit of a battle to remove pedals and noticing that some were getting tighter to re-fit, I bought a set of pedal taps and now run these through the crank to clean up the threads before refitting. Seems to help.

[PJ520]

After a bit of a battle to remove pedals and noticing that some were getting tighter to re-fit, I bought a set of pedal taps and now run these through the crank to clean up the threads before refitting. Seems to help.

Which is fine if all you are doing is using a tap to clean a good thread but if the threads have actually been damaged by e.g. cross threading you'll be removing metal and the resulting thread will be weaker. Do they make Helicoil inserts for pedal threads? I suppose the RH will be easy to find but the LH may be a challenge.

[Brucey]

you can get helicoil inserts for pedals; kits contain both types.

Unfortunately kits are also rather expensive.

cheers

[Eyebrox]

Been there, got the T-shirt. I gave up after traipsing round several garages and playing on the good nature of the mechanics at each. We tried all manner of tools and bench vices, stripped the pedal cages off to grind flats onto the axles and ran the cranks under a blowtorch. This was a new bike on which I wanted to replace the basic pedals that came with it. I gave up eventually and binned the cranks and pedals. It cost me £120 for new cranks on top of the £40 for flat pedals. And...my hands were in some mess after my week-long battle to separate the parts. I relived it all painfully in the posts above. Well done OP!

[ericonabike]

Hmm...seems my celebrations were a little previous. Temp pedals [SPDs] went on fine, but when I came to fir new folding pedals, the RH [drive] side pedal won't thread in. Seems the thread at the outside has stripped just enough to prevent ingress. Needs tapping [I think that's the expression] but don't possess kit, nor a bolt of correct size and thread to insert from opposite side to run it through. Gumption trap! My only solution so far is to cut the threaded section off the old [useless] pedal and screw that through from the other side, hoping it will create sufficient new thread. Any other ideas welcome though...