Threaded Left Crank Arm (Pedal thread)

[square_eyes]

I shipped my Dawes Super Galaxy home and have just had an unfortunate experience of not being able to re-attach my left Shimano M324 pedal.

It looks threaded, but I still have hopes as I think it's only the top couple of rings on the inside.

[attachment=5341]

From what I can tell the pedal thread is fine.

I know there are tools out there to fix a thread. I'm hoping that mine is not so bad that I need a new crank set. Can anyone offer any advice?

[attachment=5342]

[attachment=5343]

The Galaxy is around 10 years old and has a Shimano Deore crank set. Maybe it's time for a new one. I rode John O'Groats to Lands end on this one. But I think it looks worse than it really is.

Is http://www.chainreactioncycles.com/nz/en/shimano-deore-m590-9-speed-triple-chainset/rp-prod40496 what I'm looking for?

This is my first post. Thanks for the advice in advance

[cny-man]

A bike shop can easily clear those threads for you, should be at a reasonable price ($10 or less?). As the left pedal is reverse threaded you need a bike specific tap set, which would cost in the $30 range. You can try putting the pedal in from the back - may be enough with some careful triangular file work to fix the problem.

[nfmisso]

IF you have the correct tools, remove the left crank arm. Clean out the threaded hole with an old tooth brush and soap water. Inspect the threads under magnification. If it doesn't look bad, lubricate the hole generously with light oil, and run the pedal in from the backside as cny-man suggested. This will push the crap out of the hole. Wipe the mess off that is pushed out. Remove the pedal, re-oil, carefully install from the correct direction. If it is good; remove, clean everything up rags. Grease the holes on both ends of the crank, re-install on the bike and re-install the pedal. It does not matter if you put the pedal on the arm first or the arm on the bike first.

[cny-man]

...except it's much easier to get enough torque on the pedal if the arm is mounted. Also, although a little more awkward if you don't have a crank extractor you can leave the crank arm on.

[nfmisso]

(09-06-2014, 12:28 PM)cny-man Wrote:  ...except it's much easier to get enough torque on the pedal if the arm is mounted. Also, although a little more awkward if you don't have a crank extractor you can leave the crank arm on.

I have found that it is easier to put arms with tough to remove pedals in a bench vice, and then I am able to get a long wrench on the pedal......

Definitely need the correct tools for the job.

[cny-man]

Of course, but as you did not mention that and as I've found that many people do not have a good, properly mounted bench vise I thought it best to advise mounting the arm first.

[square_eyes]

Some really helpful stuff. Thanks everyone I'll let you know how I go

[square_eyes]

OK, so I was watching a few Youtube clips about crank arms late at night and had an aha moment. So much so I had to get out of bed and run down to the garage.

It turns out (no pun intended) the pedal goes on just fine, I was unaware they are threaded in reverse on the non drive side. Makes sense, of course.

And here's me going round and round clockwise, all sweaty and stuff. Hopefully this helps someone avoid the same frustration.

A little embarrassing, but got there in the end.

[Frankly]

(09-06-2014, 12:57 AM)square_eyes Wrote:  I shipped my Dawes Super Galaxy home and have just had an unfortunate experience of not being able to re-attach my left Shimano M324 pedal.

It looks threaded, but I still have hopes as I think it's only the top couple of rings on the inside.



From what I can tell the pedal thread is fine.

I know there are tools out there to fix a thread. I'm hoping that mine is not so bad that I need a new crank set. Can anyone offer any advice?





The Galaxy is around 10 years old and has a Shimano Deore crank set. Maybe it's time for a new one. I rode John O'Groats to Lands end on this one. But I think it looks worse than it really is.

Is http://www.chainreactioncycles.com/nz/en/shimano-deore-m590-9-speed-triple-chainset/rp-prod40496 what I'm looking for?

This is my first post. Thanks for the advice in advance

In general it is very easy to cross thread the pedals when you are installing them. This is why you should be careful NOT to tighten them if there is any resistance. Some people believe in greasing the threads but I do not. I start the pedal thread and if there is any resistance I back it out and try again. Another way to fix the pedal threads is to install the pedal carefully from the inside rather than the outside. This will straighten any bent threads but it doesn't work well if someone cross threaded the pedal and tightened it all of the way in. The pedal thread is usually steel while the crank insert is normally aluminum. If you make a mistake what part do you suppose will fail?

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(09-29-2014, 07:03 AM)square_eyes Wrote:  OK, so I was watching a few Youtube clips about crank arms late at night and had an aha moment. So much so I had to get out of bed and run down to the garage.

It turns out (no pun intended) the pedal goes on just fine, I was unaware they are threaded in reverse on the non drive side. Makes sense, of course.

And here's me going round and round clockwise, all sweaty and stuff. Hopefully this helps someone avoid the same frustration.

A little embarrassing, but got there in the end.

This is also the difference between English and Italian BB threads. Sort of an oh **** moment if you're unaware of it.