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-   -   removal of bent pedal (https://www.bikeforums.net/bicycle-mechanics/834568-removal-bent-pedal.html)

goldfinch 07-24-12 07:34 AM

removal of bent pedal
 
Yet another pedal removal question.

Facts:

I have a pedal wrench.
I have removed pedals on other bikes before.
I know how the threading works and what way to turn the wrench.
I removed the left pedal with ease, the right pedal is the problem.
I sprayed with WD 40 and let it sit.
The bike is a hybrid of late 80s, early 90s vintage. I do not know what the crank is made of but it is marked Shimano Biospace SG.

Issue:

The right pedal is bent. If I push hard on the pedal wrench I can get it to move a bit. But it never loosens up. Now it won't move at all.

Ideas?

dbg 07-24-12 09:42 AM

If the threaded area is bent you might have a damaged crank. Any chance you can un-bend the pedal to maybe get the threaded portion to move more freely?

wrk101 07-24-12 10:01 AM

WD40 is basically worthless as far as freeing stuff up. PB Blaster is better, Kroil is better than PB Blaster (but less available).

goldfinch 07-24-12 11:41 AM


Originally Posted by dbg (Post 14521442)
If the threaded area is bent you might have a damaged crank. Any chance you can un-bend the pedal to maybe get the threaded portion to move more freely?

I am worried about whether the crank is bent. I'll see if there is anything I can do to straighten the pedal.



Originally Posted by wrk101 (Post 14521524)
WD40 is basically worthless as far as freeing stuff up. PB Blaster is better, Kroil is better than PB Blaster (but less available).

I found some Max Penetrant in the garage, didn't help.

HillRider 07-24-12 11:50 AM

I expect the impact the bent the pedal also ovalized or otherwise damaged the crank arm threads and you may have to remove the pedal by brute force. If the arm is still ok and the crank worth the effort, you may need to helicoil the pedal thread hole.

goldfinch 07-24-12 12:06 PM

Whacking on the pedal did nothing to free it or straighten it. I am concerned about what exactly is damaged and agree with HillRider that the crank arm threads may be damaged. With everything I have to increase leverage I just get a slow moaning turn of the wrench and nothing frees up. I am a 103 pound woman. I'll see if my beefier cousin can free it by brute force.

temon00 07-25-12 02:13 PM

Brute force is one way, but I prefer to use a breaker bar to gain leverage. I use a piece of PVC around the wrench handle, or another, bigger box wrench.

Can the pedal go back the way it came? It may give you a clue as to whether or not the threads are round, or break free any corrosion that's sticking the pedal in place.

Chombi 07-25-12 03:12 PM

Use the crank arm to your advantage by gripping the pedal wrench and crank arm together and squeezing them towards each other like you would do with scissors. Squeeze the two towards each other with both hands if you can but be careful not to trap and pinch any part of your hands between the wrench and the crank arm. You might want to wear a pair of work gloves to protect you hands and cushion them against the usually thin edged pedal wrench. I've loosened a lot of really tight pedals crank bolts this way and avoided too much "drama" in the form of pulled muscles or flying tools and bike parts.
BTW, forgot to add, you might want to take off the chainrings from the crankarm to give you more room to grip on to the crank arm.

Chombi

jyl 07-25-12 10:40 PM

If you place the right crank at 2 o'clock and then position the pedal wrench so that the free end of the wrench is a couple inches above the center of the crank, you can place your shoe on the free end of the wrench and step down, using body weight. Wear closed toe shoes with sturdy soles (tennis shoes are ok). Make sure the wrench is fully on the pedal spindle and press down gradually. If you don't have enough arm or hand strength, this can work.

rogerstg 07-26-12 06:37 AM

Apply heat to the end of the crank. It'll make removal much easier by expanding the aluminum.

Asi 07-26-12 07:17 AM

First apply some pb blaster/liquid wrench penetrating oil (or wd40 but it far less useful than a real penetrating oil).

Adding heat is also a good idea not only for the expansion of AL (and less expansion of the hard steel pedal spindle), but most threads have a paste that acts as thread sealant/thread locker (not the case here)/ thread protecting/antiseize whatever. This paste loosens with heat (this is a very useful tip for stubborn bolts that have this paste on threads and usually found in mechanical bolts on engines/transmission/chassis of cars/trucks/motorcycles. on bikes.. idk, it's not a widespread practice of applying loctite thread grease of some sort on bolts like in cars/aviation maintenance, but more and more I see bike bolts with various thread pastes applied on threads so who knows.. )

temon00 07-27-12 12:19 PM


Originally Posted by goldfinch (Post 14522122)
I just get a slow moaning turn of the wrench and nothing frees up.

This confuses me... BTW, did you get your pedal off?

Kimmo 07-27-12 12:51 PM


Originally Posted by Chombi (Post 14527553)
Use the crank arm to your advantage by gripping the pedal wrench and crank arm together and squeezing them towards each other like you would do with scissors.

This is good advice.


Originally Posted by jyl (Post 14529010)
If you place the right crank at 2 o'clock and then position the pedal wrench so that the free end of the wrench is a couple inches above the center of the crank, you can place your shoe on the free end of the wrench and step down, using body weight.

This is what I'd try next, but it's sketchier; proceed with caution. For instance, the wrench may swing into the crank and gouge the hell out of it, or worse things could happen. You need to be very deliberate in your movements with this.

goldfinch 07-28-12 09:05 PM

I've been gone for a few days, I don't have the pedal off yet. I am going to ask for a stronger person's help. :) I am out of tricks. I did talk to the LBS guy I know and his thought was with the moaning of the pedal and not freeing up that it got cross threaded a bit when it bent or that the pedal was put on incorrectly. He wasn't encouraging and thought that odds are that the crank threads are damaged. The crank is hardly worth repairing.

goldfinch 08-01-12 06:20 PM

OK, I brought the bike over to my cousin's and he put the crank arm in a vice, put a pipe on the wrench, and slowly got the pedal off. Not surprisingly, the threads were stripped. Who knows how it happened, but a young person riding aggressively is the probable cause.

The bike isn't worth much of anything. Any kludgey fixes? The crank is one of those weird biospace kind of oval cranks. I wouldn't want to spend much to replace it.

jim p 08-01-12 06:29 PM

My guess would be to use a heli coil to replace the damaged threads. A machine shop or a very good bike shop might be able to make the repair. I don't know what the charge would be but it might be in the $25 range.

DieselDan 08-01-12 07:09 PM

Sometimes threading the pedal in from the rear can retap the threads enough.

goldfinch 08-01-12 08:54 PM


Originally Posted by DieselDan (Post 14556223)
Sometimes threading the pedal in from the rear can retap the threads enough.

I'll at least give this a shot.

jsdavis 08-01-12 11:17 PM


Originally Posted by jim p (Post 14556073)
My guess would be to use a heli coil to replace the damaged threads. A machine shop or a very good bike shop might be able to make the repair. I don't know what the charge would be but it might be in the $25 range.

Would new crankset like Shimano Acera work? Those are about $30 so not much more than inserting a helicoil. I don't know how that compares to the Biopace cranksets though.


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