How would you get THIS off?

I've run into a stuck fork cap: I made the mistake of heating it, but that just made it worse. ANY HELP? Or do I need a new left fork?





Dremel it out?

Gasp! Heat on the tube only might have been the ticket, so it would expand a bit. Have you grabbed it with a channel lock plier?

At that point i would use a monkey wrench.

I would try heating the fork tube,loosening the upper pinch bolts and try a pipe wrench on the edge of the fork cap above the fork tube. Good luck

A Press, Torch, Aerokroil, and a Pipe wrench.

Dremel.

Carefully cut as much as you can off. Then pry out the internal thread with a sharp chisel. File a groove in the internal bit with a triangular file to weaken it if needed.

Wrenches may distort the cap out of shape and make it harder to remove. Maybe.

Night TWO trying to fix this mistake. Purchased a new cap on eBay for $42 !! Ouch! Painfully mistake, but know I'm thinking I should have just bought a second fork on eBay for $100 and had some extra parts to play with. Tonight we were able to get the air valve and cap off (wanted to save this as the new cap does not come with these).

Lossened the tripple tree, Tried inserting a LARGE screw tap, but we did not have the right square driver head the rear of the screw tap needed. Tried heat and a medium sized adjustable wrench on the rear of the tap, even tried tapping wrench with a hammer. NO luck. Next is to try an air impact driver with square driver socket and heat.

Plan B: weld the right size aluminum bolt onto existing cap and use large tort wrench again.

Place C....Dremel carnage

Plan D...new fork


Thoughts?

Tap a chisel along the edge in the counter clockwise direction. Or, get a little slot there and use the hammer & punch.

I would try this after putting heat to it.

I was just about to say the same thing!

Heat works to remove stuck bolts in a few ways:
- breaks loctite bond
- helps break fused metals (by corrosion)
- expands the materials

So, heat should be applied to the outer material.

I think that your stuck fork cap is out of shape and applying heat won't loosen it enough to screw it out.

Have fun with you Dremel.

Let us know how you go...

Also, consider the materials involved. Aluminium will expand at a greater rate than steel.

Using heat to remove a steel bolt from an aluminium housing can be successful, because the aluminium will expand "more" and create clearance.

Rapid cooling would be better for aluminium bolt in steel housing... got any liquid nitrogen handy!?

Maybe, & this is just a guess. Make a mold by putting a slightly smaller tube over your fork cap, line the inside with saran wrap, fill with water & put it in your freezer over night. Soak the area with PB Blaster, or similar product, & let sit overnight.

Next day gradually heat up the fork tube. Place premade ice tube over fork tube cap & use a good quality, proper sized pipe wrench. If it doesn't work, take it to a pro & bite the bullet. Good chance it'll be cheaper in the long run.

All the above could work. I would remove the air fitting and see if you can get a large easy out (bolt extractor) into the hole. If the alum is thick enough you may get enough grip to turn it. May have to drill the hole a bit to get rid of the threads to provide more grip. Before that I would remove the fork and turn it upside down overnight. That will let some of the fork fluid penetrate the threads from the inside. I sure hope you are undoing the top triple clamp bolt first. That is usually the main cause of the rounded off fork cap. Hope this helps. To me you still have enough meat left on the cap to grab with something like vise grips. Cam.

Ruffus idea wont work using ice, but you could do similar with JB weld. Add fiberglass strands to the JB is give it super strength.

The problem with heat in this case is that the aluminum cap will expand twice as much as the steel tube, making it tighter. I would still heat it several times, letting it cool down in between, before trying to turn it. I had a drain plug one time that would no way come out without rounding the corners. After several applications of heat then cooling, it turned out with my fingers.

X 2 for the pipe wrench-

Dissolve it in chlorine!?

I have a 6' alloy monster you can use but I don't think it will leave much left. There would only be 2 teeth gripping.

Xcuvator is correct. Be carefull with heat cause you can also melt the aluminum.
I just did several vintage bikes. Except before rounding the nut off. I did this:

Remove air screw. Use a socket the same diameter as chrome fork tube. Put it over damaged cap.
use a hammer on socket, to send a shock wave down threads. Then use, wrench, in your case try pipe wrench. Did this on rest of my vintage stuff and never rounded one cap. Just don't get carried away and hit the cap so hard you drive the cap down in fork damaging threads inside mating fork tube. Your just giving it a good wrap to send shock wave to seperate the cap and tube from electrolysis.

I do that and cap comes right off. I had one more stubborn, like yours. I think you can get a lead hammer at Fastenal. I hit the chrome tube right below cap. I used aluminum behind fork tube so no damage to chrome or tube. I dis another top shock wave then did a side one on tube over threads. It backed off normal.
I used the lead hammer and gave a shock wave on the reservoirs on the piggy back shocks.right over the threads on rervoir. They broke loose and came right off with a strap wrench, with no damge.

Plus you'll have a lead hammer you can use without rounding stuff over in future.

If pipe wrench slips. I would cut a flat spot out of cap on opposite sides with a hack saw. Like a two sided nut. So wrench has a good bite.
Using a hacksaw , you can be careful cutting cap as you get close to fork tube.if you do nick it you can file the top later.

You might want to go around the cap between cap and fork tub to cut a small slit between cap and tube. Soak in peneterating oil overnight then proceed.

I have done the shock thing on old plumbing pipes, oil well casings that are rusty, corroded and kinda bonded together, before even using a wrench. They break loose all the time.

Good luck and you are at your own risk.

Also pull that tube up higher out of the triple clamp. Then re clamp. That clamp might be crimping in on tube and threads. Maybe why it wont crack loose.