Fixing Dented Rim

[GATOROC]

During a ride late last year I caught a rock perfectly on the edge of my rim which put a nice little dent in it. I tried using a 2x4 and sledge hammer to get it back into shape, and it moved a little, but not far enough before breaking the 2x4. I've heard of using heat and a press to get a rim back into shape, but are there any other suggestions? I have heat (oxy/acetelyne) but I don't have a press.

It's not a huge deal since my Tubliss is still holding air, but I'd still like to get it fixed if possible.

, on Flickr

, on Flickr

[kdxsully]

That’s pretty bad man. You could try taking the tire off and heat that sucker up a lot and try the 2x4 again, but everyone else here is gonna say you need a new rim

[Julien D]

That is pretty nasty. I'd try heat and a deadblow or 2lb sledge and wood. It's possible that you will weaken and/or crack it though.

[SS109]

Fixing a dent in aluminum is pretty tough. You have to get the bend, and the immediate around the bend, very hot before trying to work it. Even then you take a risk of cracking it. Plus, the aluminum will loose it's temper (heat treatment) so it will always be softer in the area you heated and more prone to be dented again.

If (I really stress that if) I was attempting to repair that dent without a press, I would try to get the temp of the work area up to about 1000f (537c) degrees before working it. Wood will burn at those temps, plus take away some heat, so only put it to the rim when you are ready to work it. When working the metal figure out which way it needs to go and position your wood block and hit accordingly. Hit the wood using a 2lb sledge and pay attention to how much the metal moves, and how it moves, with each hit and adjust if necessary. You'll have to reheat the area after a couple of hits as the work area will dissipate the heat into the rest of the rim (and wood) very quickly and the risk of fracturing the rim will increase. Even doing it like I'm saying you would take a big risk of cracking the rim.

Personally, I would just leave it alone or lace up a new rim.

[GATOROC]

Thanks for the suggestions/ideas!

[bufftester]

The biggest worry is losing pressure there where the tire bead seat is compromised. If it's still holding air I'd probably (OK I would definitely) ride on it while looking for a replacement. If you do rework it and it cracks, it can be welded and repaired.

[GATOROC]

The biggest worry is losing pressure there where the tire bead seat is compromised. If it's still holding air I'd probably (OK I would definitely) ride on it while looking for a replacement. If you do rework it and it cracks, it can be welded and repaired.

Sounds good - thanks. Too bad a nice set of black wheels costs so much. I really like the look of Ericr's bikes!

[pumpguy]

Fixing a dent in aluminum is pretty tough. You have to get the bend, and the immediate around the bend, very hot before trying to work it. Even then you take a risk of cracking it. Plus, the aluminum will loose it's temper (heat treatment) so it will always be softer in the area you heated and more prone to be dented again.

If (I really stress that if) I was attempting to repair that dent without a press, I would try to get the temp of the work area up to about 1000f (537c) degrees before working it. Wood will burn at those temps, plus take away some heat, so only put it to the rim when you are ready to work it. When working the metal figure out which way it needs to go and position your wood block and hit accordingly. Hit the wood using a 2lb sledge and pay attention to how much the metal moves, and how it moves, with each hit and adjust if necessary. You'll have to reheat the area after a couple of hits as the work area will dissipate the heat into the rest of the rim (and wood) very quickly and the risk of fracturing the rim will increase. Even doing it like I'm saying you would take a big risk of cracking the rim.

Personally, I would just leave it alone or lace up a new rim.

Wow! That hot?

That's awful close to Aluminum's melting point which according to the Materials data page in my copy of Machinery's Handbook is 660*C or 1220*F.

I have seen the use of heat recommended before when trying to straighten bent LA rims, but I had no idea the temperature needed to be that high.

Have you had any personal experience using this much heat?

[SS109]

Have you had any personal experience using this much heat?

Yeah, but it's been 20+ years since I worked at the place where an old guy was showing me how to do it. He knew how to control the heat really well without any technology to help but I have no clue if we actually got to that temp. I just know what he told me and he walked me through it. Big thing I took away was to get it as hot as you can without melting it to reduce the chance of fractures. If I was doing it now I would use my infrared temp gun to keep an eye on temp while heating it in my press. Like has been mentioned, if you fracture it you can always weld it up. I don't have the equipment or skill to weld aluminum so the heat method would be the way I would go sense I do know it can work.

[pumpguy]

Thanks for this information, most informative.

I have a torch, press, IR gun, and a few dented rims lying around. My last attempt at trying to repair a dented rim resulted in a crack and left me a bit discouraged. Now with this information, I just might try again and see what happens.

[kdxsully]

You might change your name from pumpguy to rimguy

[SS109]

Just don't set yourself on fire! Oh, make sure you remove the rim strip and any residue from the rim or it will burn!

[Molly's 70]

This is how my old welding supervisor taught me to heat aluminum to a workable temperature. I was going to try & explain it, but found a You Tube video. This technique works well & has been foolproof for me. I didn't realize this info was well known. Everything is on YT. lol

[kdxsully]

That kid is hilarious. “I’m not wearing safety glasses cause I’m very careful”

You think that sharpie trick would do the same?

[SS109]

This is how my old welding supervisor taught me to heat aluminum to a workable temperature. I was going to try & explain it, but found a You Tube video. This technique works well & has been foolproof for me. I didn't realize this info was well known. Everything is on YT. lol

That's basically how I was taught to do it other than the blackening it up and I was told to heat an area larger than the area where the damage is.

[Goat]

Hi Gator, did you end up replacing rim?
I didn’t want to be complete copy-cat, so tweeked the front instead.
Is it worth buying and lacing new rim?
I am thinking replacing whole thing off eBay and keeping this in the truck, as a spare.

[GATOROC]

Hi Gator, did you end up replacing rim?

No, I'm still running the "aesthetically pleasing" bent rim. It doesn't leak air, so I'm just going keep using it. I might eventually pick up another rim and set it up for TuBliss, but it's not a priority at this point.

[KDXGarage]

Goat, that rim had a chemical reaction to the half bottle of Armor All you used on the tire.

That front wheel does not look real bad.

[Goat]

Haha! Believe me that armorall stain must be from someone besides me. “If the pressure washer doesn’t take it off, it must be meant to stay there”.
I ran it bent at the MX school yesterday. And all felt the same. So I may not worry about it.
...except that since I started looking, eBay is calling me with this tasty looking treat.
https://www.ebay.com/itm/293479228385

[KDXGarage]

That looks good. That tire is not seated on the bead. That's odd.