Stuck pedal
 

I recently scored an '86 Miyata 310 that some genius was trying to turn into...I dunno what.

Among other things on it are some crappy and mismatched MTB pedals, one of which I can't bust loose at all. Worse, the spindle is soft...wrenches, vise grips, and other pliers are just rounding it off, can't get a grip on it at all. It's the left pedal, and yes, I'm turning it the right (left) way. I've tried penetrating oil, a heat gun, etc...all the normal stuff, and I'm making no headway at all.

It's occurred to me to try and drill it out, but I don't want to bugger up the crank arm, since it's an original Miyata part and not easily replaced. Any advice would be appreciated.

I'd disassemble the pedal leaving only the spindle, put a few drops of DOT 3 brake fluid on the joint (keep it away from paint!), and get my 12" pipe wrench on the remains of the spindle. With the left crank arm forward, parallel to the ground, wrench handle facing to the rear, put one hand on the pedal and one hand on the wrench, and put all your weight on it.

If that doesn't work, pull the crank arm and drill it out. The good news is a regular right twist bit will help unthread it.

I fought a stuck pedal once, and won by removing the crank arm, placing the arm in a vice (use wood and/or rags to prevent damage to the crank arm finish), pedal pointing up ward (so you're not relying on friction from clamping force to secure the crank arm). then apply sufficient leverage.

Followed your procedure, except for the brake fluid (not sure I have any), and after monumental effort, I got the damned thing to turn. Even then, it turned very grudgingly, and I was afraid that I'd stripped the threads on the crank. However, I kept turning, and sure enough, it was spinning out. Put the vise grips on it to spin it all the way out, and the crank is in good shape. I thank you.

...and I'm leaving the pipe wrench in my bike toolbox. Dang.

Excellent! Thanks for the feedback too.

Pedal forward, wrench handle back, using body weight (works the same both sides of course) is a great trick to know.

​​​​​​​For the left, left isn't right. Right is right, 'cause it's the left. Right?

Right. One just has to remember to turn to the rear of the bike to remove, and to the front of the bike to install, both sides.

Now that you have gott4en that one loose, don't forget to apply grease or anti-seize to the threads of the new one. I use Tef-Gel for such things.

both pedals screw off towards the rear of the bike.

I just had this same problem, having to cut up the arm to get my old Primo pedal back. The bare aluminum threads, and bare steel threads galvanized together.

"Right-Right, Left-Left". Glad you got it off. Better to ask, than to fight it off.

Glad that the pedal was removed without damage to the crank! Have you checked to be sure that a “proper” pedal is able to be threaded onto the crank arm? Always hard to say what “Bubba” did to get the cheapo MTN bike pedals mounted. I suppose it’s possible that some level of thread locker was used.
Congrats on the Miyata score! Nice bikes. I have two, an ‘84 Seven Ten and an ‘85 Two Ten. Trying to keep them mostly “period equipped”.

Yeah, the cranks are good. I have some MKS Sylvan pedals on them now.

do you have a pedal wrench? if not, they're good to have around. w/ 3 bikes, riding year 'round, it seems like every few months, I'm changing or swapping pedals. anti seize yes, but there's some technique to that

If it is relevant for someone else, the best way to remove the pedal is while you have both crank arms on the bike. Take a piece of rope and wrap the opposite crank arm together with chain stay tube (many turns). Then a good wrench and a pipe, if needed, and the pedal will go off. This method never failed in my life and I have removed hundreds of stuck pedals. The downside is that most of the time thread in aluminium crank is damaged. But this will get your pedals off.
/R

Most of the time folks don't want to destroy the cranks, even if the pedal is stuck. Just saying. :innocent:

I fully agree. That's why applying grease before mounting is crucial ;)