Wheels [JB] Welding some double wall aluminum rims??

[sparky]

So... yesterday I was on this sidewalk, right...

And I took the opposite way back, and wasn't expecting this minor tectonic plate shift in the sidewalk, right...

So I barely see it, slam on my brakes, slow down good enough to me, hop over it with my front....

And then BONK, the back rim hits it fairly hard. It keeps riding for a few revolutions and then the back wheel became extremely difficult to pedal, then locked up.

I had a fairly big dent in the rim, but the kevlar tires were still holding air (Best. Tires. EV. AR. -- Shadow Undertaker Kevlar, 20")!!!

Took that side's brake pads off and kept riding no problem at all. Rode some more today, no problem. Eventually I realized I just couldn't deal with just one brake, no matter how RARE this dual-freewheel hub is. So I started beating on it, even tho everybody said I couldn't do it.

I did it. It's almost back in shape!! The rim did crack, but I think that I could weld it. I remember somebody saying something about how they used the 2-part JB Weld and it held some plane parts on. I think that might be far better than heating up the aluminum rim, and should be slightly easier to sand the brake side off.

My questions are...

(1) JB Weld over regular weld?

(2) Getting the brake-side surface flat is my only real objective, right? Leaving some weld lumps on the inside of the rim shouldn't affect balance incredibly much on a 20" rim at 25-30 mph, should it?

(3) Should I get the one bent spoke corrected before or after welding, sanding?? HMMM?

My logic isn't working properly in answering this question... because I've never adjusted spokes and a guy who does adjust them says "it wouldn't matter anyway, because it's so bent". It's not really all that bent anymore, but the crack is a problem, for sure... which I think JB Weld might handle just fine!

(4) Anything else I should worry about?!?

 

[olow]

im a firm if u need a new rim u need a new rim after all ur gonna ride on it better be safe then sorry

 

[sparky]

Well... to answer my own questions without any experience yet...

(1) JB Weld sounds great

(2) An even braking surface seems about the only real objective here.

(3) I guess I'll take the rim to the LBS one more time and ask whether I should get the one spoke replaced befor or after JB welding.

(4) Only thing else I need to worry about is make sure the JB Weld is 2-part, and make sure that I prepare the metal properly before applying it!!

 

[srdavo]

IF your LBS suggests a another wheel or at least a new (or used -unbroken) rim laced to your hub.... they are only interested in your safety.

JB Weld is glue.

Leaving some weld lumps on the inside of the rim shouldn't affect balance

But it could affect how your tire seats on the rim.

Ultimately.... It's your decision & your skin.

I vote Replace the rim or wheel.

 

[sparky]

Thanks, srdavo! I really do appreciate the concern, but I don't expect any problems and am definitely not going to go over 15 mph over the next couple weeks.

LBS Guy #1 said that it was beyond repair, "because it was to far bent out of shape".

Gotcha, but I bent it back. Sure it has a seemingly minor crack... but I am really not expecting the regular ol' 2-part JB Weld that dries overnight to have any problems "being the glue" that holds this minor crack together. It said something like 3950 psi, so I think it should be able to handle it!!

Only problem is that when I showed the wheel to LBS Guy #2, he *did* remind me about braking forces, which I was not really thinking about before!! I was only trying to get the brake surface flat to not rub the brake pads, but... I still think after overnight drying, and a good sanding.. this thing will still be able to hang. :helmet:

He said that the bend in the spoke was no deal, we'd just need to tighten it. Guy #2 wasn't quite as dramatic as to saying it couldn't be done after he saw it back in shape. It's not perfect, but perfect is the enemy of the good!

 

[Turtle Tedd]

Soarky...JB WELD WILL NOT WORK...get another wheel or get ready for a trip to the hospital

 

[olow]

one thing u dont want is the rim to break and fold in2 as some rims ive seen that were in good shape but if u do well god bless and good luck

 

[sparky]

I think it will!!!

I think 3950 psi is good enough for the size crack that it is, and the shape is already back to normal, minus what I can sand... so I don't see the problem just yet.

I found this comment in another forum...

Weld...but for future patches, only use Jb where you need some heat resistance. It's good up to 600 degress, but there is much stronger epoxies available now. Superweld has a tensile strength of 7,450 psi, Jb is about 3,950.

I think it just might work....

The thing was working just fine with the big dent... I don't see how the brakes are going to overheat one little section of the rim enough to re-crack it, but we'll see tomorrow.

Gotta set it overnight to get that 3950 psi tensile strength!!

 

[sparky]

Mmmkay...

I took it by the LBS after it dried, and the guy puts it on the truing station thingy. He tells me that it is slightly bent, which i already knew, but it was "within tolerance". Sounds good!!

He told me that even tho the spoke is bent, it's got the proper tension, so there was no benefit to tightening that one spoke. Also sounds good!!

Put the tire on, used the hand pump and rode it around for a bit without brakes. Rode back up to the shop to get some pads. Everything's looking great!

I get back home, then decide to let the air out of the tube and then air it up with the compressor to a higher psi (these tires say something like 120 psi max!).... I put the brake pads on, then start to ride. Instantly, I could tell something was wrong. I look down and the rim had already cracked.

I'm going to try one more time at this, then I'll brake down and pay the estimated $150 for a new rim to be laced with this hub!!

I don't think that some of my jb weld mix was good enough, because some parts were more like rubber than the rest, which was more like steel. Today, I made sure to mix the 2-parts together extra well! I shoved it in between the cracks, which I was unable to do yesterday because I'd already hammered it back together. There's definitely a mixture IN the cracks now. Did everything else the same.

But tomorrow, I'm going to apply a second coat of jb weld to the inside of the rim, right behind the crack.... I think that will even hold the higher PSIs!!

I'm almost willing to bet money that it will work this way. But we'll just have to wait 'til Monday!!

 

[Elmo]

Keep fooling with a trashed rim until you wind up in the hospital.