Problem fitting new pedals

Distorted Vision

Senior Member
I fitted new M324 pedals to my Giant Roam 0. The old pedals came off easy enough with a pedal wrench. The new ones fitted first time also without any problems. But I realised I'd forgotten to grease the threads. They both removed again without issue but after I greased with Copaslip they both wouldn't tighten fully and ended up with the axle into the crank at an angle.

I removed them and carefully cleaned out the threads of the cranks. I noticed there slithers of metals inside. It took two attempts at cleaning but both finally tightened fully without any problems.

I'm wondering what I did wrong? I'd like to know for future reference. Surely it couldn't have been caused because of simply not using grease the first time?

Many thanks.
 
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Slick

Veteran
Sounds like you have stripped the thread.
 

Slick

Veteran
I did the same on an old mountain bike but stopped before doing any real damage and was able to carefully realign them and refitted them. Hopefully you will be as lucky.
 
OP
Distorted Vision

Distorted Vision

Senior Member
It probably wasn't clear from my post but I've already been able to refit them successfully. I think you're right but wondering what cause the thread to strip slightly.
 

Heltor Chasca

Out-riding the Black Dog
What @Cycleops said. New crank day? Unfortunate. Sorry. Check to see whether it’s the pedals or cranks (or both) that have been damaged before you buy anything.

When you’ve got your new bits, put the pedals on with just your thumb and index finger. You obviously understand the left one tightens in an anti-clockwise direction and the right is normal so that’s good.
 

robgul

Guru
As stated you've cross-threaded the pedal and ripped the soft thread. If it's the non-drive side and you're not too fussed* then you could probably find a single crank of the same length as a replacement (you're LBS's "box of bits in the corner of the workshop" may be your friend)

* the casual observer can't see both cranks at the same time!! (I had odd cranks on a bike for a while - that was because someone had stripped the fixing bolt thread on the non-drive crank)

Rob
 

MichaelW2

Veteran
Noting that one of the crank arms had a reverse thread, I feed my pedals in by hand, rotating the wrong way until the threads click, then turn the correct way, by hand if possible, at least a few turns.
 

Milkfloat

An Peanut
Location
Midlands
I retapped an expensive carbon crank for a friend who somehow managed to get the right hand pedal on the left hand crank. It is still holding up more than 10k miles later, so I don’t think it is always terminal.
 

Milkfloat

An Peanut
Location
Midlands
[QUOTE 5501609, member: 9609"]I know someone who achieved that impossible feat too, they had it half way in, how do they do it ?? :wacko:? - It was a bit like that 'some mothers do have em' sketch
I just smiled and suggest LBS.[/QUOTE]

It seems that brute force was involved plus a length of scaffold. He did realize what he had done wrong and so far I have managed to keep quiet about it on group rides, mainly because he has a lot of 'dirt' on me too.
 

Bazzer

Setting the controls for the heart of the sun.
As said upthread, if you have to remove the pedals again, whether for a new crank or retap, one way to stop the cross thread is to put the pedal to the crank arm and by hand turn it the wrong way. Feel for the step down as the crank/pedal threads reach the start of their threads, then turn the pedal by hand the correct way. If the threads are clean and not crossed, you should find they turn comfortably by hand a least for a few turns. If in any doubt just reverse and start again.
 
OP
Distorted Vision

Distorted Vision

Senior Member
I actually bought a replacament Shimano Deore T521 crankset a few years ago when it was on special offer at Bike-Discount figuring I might need it one day.
I'll see how the pedals go for now but I'll just take it to my local bike shop if I have any problems.

I think you'll find the pedals won't stay in place and will eventually work loose as you've stripped the threads so I'm afraid you'll need new cranks :sad:.
 

12boy

Über Member
Location
Casper WY USA
I too have had stripped threads, both at the pedal and the BB end. The BB end was resolved with having those threads retapped while still on the bike by my LBS so I could remove the crank arm. The pedal can be done with a tapping tool applied from the inside, or if you can`t get one, using the pedal itself or a bolt with those threads and carefully inserting it, again from the inside. Use some oil in the process. This should clear the outside threads enough to get the pedal started and get into the undamaged area.
 
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