njkayaker

No one is "busting your chops" for saying this!

It's your position that repairing AL (a temporary repair) in the middle of nowhere is as likely as repairing steel that people are not quite convinced of.

No one is (except for the odd pacificcycle dude).

That story doesn't actually refute the "repair in the middle of nowhere" contention. It supports it.

The sole point is to get home.

Who is claiming that it is easy?

All that anybody is claiming is that it is appreciably more likely to be able to repair a steel frame to a usable state. (Keeping in mind that there's a good chance that a broken frame will be beyond repair.)

This is all that one can reasonably expect.

And it's not like he would have been better-off not getting the repair.

robow

If I may ask a question,
what are the chances of using something like those Alumiweld or Muggy weld alloy rods and a propane torch in order to temporarily repair an aluminum frame, since most everyone has a propane torch available and you could easily carry a couple of those repair rods with you? They sure make it look easy in their videos but I don't have a clue how strong the bond would be and if the allow itself would hold up to the stress.

https://www.alumiweld.com/

staehpj1

No I haven't tried it, but it looks like it is more like brazing or soldering than welding. Not sure if it is any better than something like J-B Weld which is actually an epoxy. I wouldn't use either on a permanent frame repair at home bit might try them as a emergency repair.

cyccommute 

Yes he finished trip after having it welded twice and breaking those welds and burning a hole in the frame and having to ride a very squirrelly bike. He's damned lucky the thing didn't crumble under him. I wouldn't exactly call his repair 'successful' nor permanent. The bike was junked afterwards.

Rob_E

Some things that have come out of this thread:

1. If you break your frame, any frame, it is very likely cheaper and easier to replace it then fix it.

2. If you're not in a position to replace your frame, you have nothing to lose by attempting to fix your frame.

3. The goal is to finish your trip. The reason for any attempted repair or for choosing a bike based on "repairability" is to increase the odds that you finish your trip.

By that standard, that poor, abused steel bike is the poster child for this thread. It was possibly the worst imaginable successful repair. Seems that bike went another 400 miles or so after the frame was technically ruined. If I was a week away from finishing a tour in a foreign country, I doubt I would pay to ship in a new frame and build up a new bike just to keep going. I might try to get a local bike and push on, but even that would likely involve leaving a lot of still-useful, still valuable bike parts and components behind. Seems like the best possible solution is to somehow get your bike moving enough to get to the end.

bud16415

The OP wanted facts and only facts on frame repair and I have to say I haven’t had the opportunity to try this on a frame but have repaired quite a few other things with this method and it is what I would try given the on tour without much in the way of tools etc. to attempt an repair that would be strong and safe and able to be reversed when I return to make a correct repair.

I have had good luck with fiberglass tapes and cloth and mat and resin. You can buy the stuff at most auto parts stores or even wal marts and the built up layers wrapped around a crack or break in a tube would make a strong cast. You would have to build up a thick layer and go maybe 2 inches each side the problem. All you need for tools would be a plastic cup to mix in some sticks to stir and a cheap paintbrush maybe and use your pocket knife to cut the tape. If you wanted to reinforce the repair you can glass in any kind of wire etc.

I have some scrap bikes around and to bring this to fact and only fact status I might try it out over the weekend. What is a likely spot to saw apart to try and repair? Down tube? Do most cracks start at a joint or from a dent in the middle of a tube?

We have used the alumiweld in the shop and it’s not a bad product. Even did the weld a soda can to a piece of thick aluminum thing and it worked.

njkayaker

1+

I'm amazed that this is so hard for some people to understand.

njkayaker

His frame problem was also fairly extreme.

Anyway, unless you are taking the position (like pacificcyclist) that one should never attempt to repair a frame, it's not clear how this story helps you.

He would not have been better-off with an AL frame (and it's the contention of some people here that he would have been worse off).

The issue is whether steel gives you more options/probablity to recover from a frame problem (not that it will allow all frame problems to be fixed).

Yo Spiff

I've used the granola bar wrapper tire boot, and yes, it works. I don't have any input on the frame question, however.


Granola wrapper tire boot by Yo Spiff, on Flickr

Rowan

Drive-side chainstay.

The issue probably will that you might need to insert a dowel (as in a whittled down limb from a tree) or something into the tubing or at least lay it along the outside like a splint. Otherwise, the stress and strain that caused the "breakage" in the first place will likely work the glass and matt the same way.

A really difficult one might be the derailleur hanger. Likely to be ripped off or at least bent on an alloy bike when the RD goes into the spokes. Could be interesting trying to get that all back together, too!

Have fun. Working with fibreglass like that.

njkayaker

GU packets work too. So does Tyvek. As well as the Park tire-boots.

What you want for a tire boot is something that is flexible but doesn't stretch and is reasonably strong.

The main idea for a tire boot is to keep the inner tube from ballooning out of the tire casing.

cyccommute 

There have been lots of posts along the lines of 'aluminum can't be repaired in the field', 'aluminum is impossible to repair in the field', 'steel is easy to repair in the field', etc. I just saying that equipment for aluminum repair is far more readily available given the proliferation of aluminum parts in the auto industry in the last 20 years than it was a couple of decades ago. If you can repair an aluminum car part in the middle of nowhere, you can repair an aluminum bike about as easily as you can as steel one...which isn't all that easy.


What do you think the whole "it needs to be heat treated" line is about? A temporary repair such as the kind that BF123 had in China to an aluminum bike wouldn't need to be heat treated.

And, again, what about aluminum makes it so that you can't do the same thing with it? The sole point is to get home. Needing to heat treat an aluminum repair isn't necessary.

I suggested at the time that he consider alternative transportation and if I were in the same situation I would have taken the train to the end. There are things you can break on tour that will end the tour. A frame that is pretzelled like his is one of them.

Um...everyone. There is this constant refrain that steel can be repaired anywhere by anyone. All you need is some heat and you are ready to roll. That's not true. And BF123's story demonstrates that quite nicely. He had to have several repairs made to finish the last 500 miles of his trip. He rode a bike which, personally, I would consider very dangerous to ride. His welds didn't hold for longer than a little while.

I've had a steel frame repaired and I've had an aluminum one repaired. The aluminum one was easy to repair. The steel one required far more skill.

Yes, his trip ended without the bike falling apart but given the amount of damage and the number of fixes, his trip could have easily ended such that he wouldn't have been better off getting the repair.

cyccommute 

Again, for about the 10 time, what about aluminum makes you think it is impossible to repair temporarily? It's used in lots of places in lots of parts of the world. A thin steel frame that is outside the experience of many...if not most...amateur and many professional welders isn't any less impossible. Look at that last paragraph of Massive D's again.

I think most people expect too much.

njkayaker

massived (it appears) has/had the position that heat treating was necessary for a temporary repair. That you disagree is OK. That you are assuming he is talking about a 1st world permanent repair ("not getting the point") isn't OK (that assumption is wrong).

Your problem is that you are partial to straw men. No one said this.

Strawman. No one has made this claim. No one.

That doesn't mean this sort of result would be the more likely outcome in the middle of nowhere. And largely irrelevant unless both occurred in the middle of nowhere.

It could be an argument for trying to repair "severe" frame problems. It isn't clearly an argument against steel.

It's not at all clear that he would have fared any better with AL. What you have to be able to answer is 1) whether there was AL repair available to him (whether it was likely), and 2) whether he would have fared better or the same with AL.
(I'm not convinced that there is a lot AL car part repairing going on in the middle of nowhere.)

azesty

Currently in Nomad's Guesthouse in Bishkek, Kyrgyzstan, lots of cyclists here, we had 20 bikes one night.

This morning a guy showed me where his brazeon for his rear rack had snapped off and he had it welded in a small village in Uzbekistan. This would not have worked with aluminium.

z

MassiveD

I don't agree, we probably need Falanx or some other metal tech to sort this out. If you had a bad bang and ripped the downtube partially or fully from the HT, any welding, factory or field, significantly weakens the tubes. But it is within specs, so it should be fine. But if you don't heat treat a tube that needs, it you are way below specs. I'm just not riding that thing. That to me is a difference, you may still get enough bailing wire on the thing or duct tape to ride it out of there. I have said over and over in this thread that aluminum is roadside repairable, but it is more difficult to weld, and less that one will come across the gear, and the result will be crap.


The thing is, a steel frame can theoretically be welded back to original strength or brazed. I think one should go into it with the idea, that the frame will need replacing. One should accept that the guy may blow a hole right through there before he gets the heat right. But I would not worry too much about it blowing up. Two different things.

It is easy to know how thick the frame parts are. For the most part the main tubes will be 35 thou, and away from the butts on butted tubes 25 thou. The HT is probably thicker, which is really all one needs to know, just favour it. The 35 is 21 gauge sheet metal, and the 25 is 24 gauge. Lot of folks weld sheet metal. And that is a common range for auto body, etc...

MassiveD

It isn't impossible, it meets the criterion in the myth that steel is more repairable. The idea that aluminum welding and welders are as common on the ground just isn't true. Most people regard aluminum welding as magic a higher form of the art, and the gear to do it is rare, apples to apples. Particularly true is that the chance of finding an aluminum welding custom frame builder is pretty near zero. I only know of a couple who do it at all. But that is just an aside obviously we aren't counting on finding a pro.



That just ins't true, there are probably 100-1 steel welders or brazers out there compared to aluminum. As far as the last para is concerned, keep in mind that it is written for stick welding. Chance of a stick welding aluminum repair, unless you bring your own stuff, is pretty near zero.

MassiveD

It is not a strong joint. Works quite well for non-load bearing, and things that need deposition to restore shape, like building up a prop surface. I would not repair a bike with it. That said, any time something sticks, is hardish, and you use enough of it, it has the potential to make a joint. That is basically how brazing works. You build up fat fillets. But this is way less effective than brass is to steel. You can repair, or build bikes using propane, and either brass or silver solder. People have made whole frames that way. So again, I think the idea of using propane tilts towards steel.