crack in frame. salvageable?

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Returnformer   1 W

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crack in frame. salvageable?

Post by Returnformer » Aug 02 2020 12:51am

so, ive been on the lookout for a cheap used ebike for my daughter to replace her electric scooter since that thing weighs a ton and she cant get it out by herself. (and if the battery dies while out youre screwed, which happened a couple weeks ago.) i found what looked like a good deal on a nakto fashion folding ebike, so i picked it up. not the best quality ebike, but its enough for her. i picked it up with my bike and a trailer, intending to fold it and put it in the trailer. i tried it out, seemed to work good, so i took it. i go to fold it to put it in the trailer, and i see that theres a bolt instead of the latch to hold the hinge closed, so it cant be easily folded. not a biggie, i dont really need it to fold anyway, just happened to be the one i found, so i stick it in the trailer and take it home. i figured maybe he needed it to be able to fold and thats why he was selling cheap, since it couldnt.

today i was looking it over at something else, and i realized that its not just the latch thats broken, the joint where it folds is actually cracked. probably happened when whatever broke the latch broke it. the bike seems in decent condition otherwise, although i havent yet tested the range. it seemed to hold my weight (200 lb) just fine, so i would think that it could hold her weight (90 lb) without issue, but im concerned that over time hitting bumps etc will worsen the crack and cause it to fail completely. although im not sure just how much stress is directly on the crack as i think the bolt on the other side thats holding it closed is taking most of it. but if that goes...

im thinking, though, that i could probably just get it welded closed, no? just have the whole crack as well as the joint itself welded shut. it wouldnt be able to fold, but as i said, i dont particularly need it to do that anyway. would that be enough? would it be cost effective? ive never gotten anything welded, so i have no idea how much something like that would cost...

thanks.

crack.jpg
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Balmorhea   10 kW

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Re: crack in frame. salvageable?

Post by Balmorhea » Aug 02 2020 1:09am

Folding bikes are garbage. They are good at the one thing they are designed to do, which is to fit in the trunk of a car or in a closet. They’re not good for riding, because that’s not what they’re for.

The correct repair for that frame would be to grind or mill out the entire ruptured hinge tube and replace it with a new tube. But that won’t make the bike good or reliable, because it never was.

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Re: crack in frame. salvageable?

Post by docw009 » Aug 02 2020 2:30am

Alloy frame? It's toast. You could get hurt really bad if a folder comes apart. If it's steel, maybe a good welder could make it a non-folder.

I have three folding 20" bikes, all with rear motors. They're fun Also have a fattire folder. Big pig of a bike.

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Re: crack in frame. salvageable?

Post by Balmorhea » Aug 02 2020 2:32am

The welds indicate that it’s steel.

Returnformer   1 W

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Re: crack in frame. salvageable?

Post by Returnformer » Aug 02 2020 3:05am

docw009 wrote:
Aug 02 2020 2:30am
Alloy frame? It's toast. You could get hurt really bad if a folder comes apart. If it's steel, maybe a good welder could make it a non-folder.

I have three folding 20" bikes, all with rear motors. They're fun Also have a fattire folder. Big pig of a bike.
according to one site, its a steel frame. (others i checked didnt specify.) that was my thought, to weld it shut completely and make it a non-folding bike. i would think that especially with a light rider it would be ok like that. maybe even have an additional support bar welded on, too.

depending on how expensive that is to get done, it could still turn out to be a good deal for the bike, provided its safe.

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monster   100 kW

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Re: crack in frame. salvageable?

Post by monster » Aug 02 2020 4:20am

If a magnet sticks to it, its steel. Otherwise its aluminum.

If its steel, you might be able to slide a thick box section down the tube.
Then you can weld it without worrying about blowing holes through it.
You need to cut the folding mechanism off first.
Test the frame by jumping up and down on it.

But easier to just buy a new frame

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Re: crack in frame. salvageable?

Post by SlowCo » Aug 02 2020 5:54am

Hairline crack.jpg
Hairline crack.jpg (181.12 KiB) Viewed 241 times

There also seems to be a hairline crack higher up. So get the paint of in that whole area and weld up every spot/crack you see. If folding isn't necessary anymore then welding the whole hinge and thus frame together (straight as possible) is best.

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Re: crack in frame. salvageable?

Post by MadRhino » Aug 02 2020 11:31am

The only good reason to ride a folder, is that you need to fold it. Then there are some pretty good folders but they are expansive for the small bike that they are. I wouldn’t even fix this one, because it is not worth riding IMO.

Your daughter deserves a real bike that is reliable, safe and sound. I would ride a crappy bike myself, if it was the only way to give my daughter a good bike.
Make it fool-proof, and I will make a better fool.
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Re: crack in frame. salvageable?

Post by Returnformer » Aug 02 2020 1:34pm

monster wrote:
Aug 02 2020 4:20am
If a magnet sticks to it, its steel. Otherwise its aluminum.

If its steel, you might be able to slide a thick box section down the tube.
Then you can weld it without worrying about blowing holes through it.
You need to cut the folding mechanism off first.
Test the frame by jumping up and down on it.

But easier to just buy a new frame
oh right, forgot about checking with a magnet. it does stick, so its steel. the bolt holding it closed is, too, which i thought might be aluminum

SlowCo wrote:
Aug 02 2020 5:54am
There also seems to be a hairline crack higher up. So get the paint of in that whole area and weld up every spot/crack you see. If folding isn't necessary anymore then welding the whole hinge and thus frame together (straight as possible) is best.
good eye. it seems to just be the lighting, though, i dont see anything now.


MadRhino wrote:
Aug 02 2020 11:31am
The only good reason to ride a folder, is that you need to fold it. Then there are some pretty good folders but they are expansive for the small bike that they are. I wouldn’t even fix this one, because it is not worth riding IMO.

Your daughter deserves a real bike that is reliable, safe and sound. I would ride a crappy bike myself, if it was the only way to give my daughter a good bike.
i hear that, but i dont see why a folding bike cant be reliable, safe, and sound. my wife has had a folding bike that i also picked up cheap used that she was using to ride to work for a while and once i got it back in shape its suited her just fine. granted, that one is a bit higher quality, although not by a lot, but i dont see why this cant be a decent bike once the crack is fixed. shes not running marathons or anything, just need something that will last 8-10 miles for her to get around with me and have a bit of fun on. for how often she'll likely be using it, which is at most once a week, if that, its not worth it to us to spend a ton on a high quality bike. my bike i spent a lot on as i use it every day for commuting etc. she wont be.

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Re: crack in frame. salvageable?

Post by Balmorhea » Aug 02 2020 2:23pm

Returnformer wrote:
Aug 02 2020 1:34pm
but i dont see why a folding bike cant be reliable, safe, and sound.
Sure. But when you add “cheap” (like almost all folders), you will definitely sacrifice those other virtues.

A folding bike is a present you buy for your car. It only works right when your car is using it.

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Re: crack in frame. salvageable?

Post by markz » Aug 02 2020 8:19pm

Balmorhea wrote:
Aug 02 2020 2:23pm
Returnformer wrote:
Aug 02 2020 1:34pm
but i dont see why a folding bike cant be reliable, safe, and sound.
Sure. But when you add “cheap” (like almost all folders), you will definitely sacrifice those other virtues.

A folding bike is a present you buy for your car. It only works right when your car is using it.
Some people ride folders, now I dont know if they live in the same city or their out of towners, thats the problem when I see someone riding a folding bicycle. I wouldnt have much confidence on a welded frame on a folder. There'd always be that doubt in the back of your mind while your riding down a hill at 30mph on the pathway.

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Re: crack in frame. salvageable?

Post by miro13car » Aug 04 2020 4:13pm

this crack shown can be repaired somehow but I suspect there are more hidden cracks , tiny .
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markz   100 GW

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Re: crack in frame. salvageable?

Post by markz » Aug 04 2020 7:44pm

miro13car wrote:
Aug 04 2020 4:13pm
this crack shown can be repaired somehow but I suspect there are more hidden cracks , tiny .
Repaired by a very good welder, ideally a bicycle builder who tig welds their bicycle, which aint common to find. Next best solution is a master welder, but most welders do one or two things very well like structural welding, metal stairs, industrial/commercial piping, truck frames and would be hard to find the right welder for integrate bicycle tubing with thin walls. I'd scrap the frame unless your just riding around the block with it, then get the rig welder a few blocks away to weld 'er up with a case of beer.

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Re: crack in frame. salvageable?

Post by DogDipstick » Aug 04 2020 7:55pm

It would take me 30 seconds per side to weld that shut in steel. I promise you wont break it again, . Ever,., .I would use a stick, and it wouldn't be pretty and shiny, with zero splatter, but would look and be very strong.

I could mig it, I could tig it, if you wanted zero splatter and perfect half-moon dimes laid upon each other.. but that costs gas and consumables and .. time for setup and good control of the weld with the mig or tig.. time... So I would probably go to the stick first. I would stick weld it in literally 60 seconds for free. Lol. You wouldn't be able to break the joint swinging a 10lb sledgehammer on a three foot handle as hard as you can, John Henry style.


I mean, yes, I suppose you could mess it up ( the weld), but plain ol regular low carbon steel is usually very forgiving and easy to put back into service without much downtime.

That crack was not cycling fatigue, it is stressed.., torn... over-bending backward I would bet. I bet you could even braze it if you took the time to prep and close the joint as much as you can, then braze reinforcement over it.
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Re: crack in frame. salvageable?

Post by Returnformer » Aug 04 2020 9:02pm

DogDipstick wrote:
Aug 04 2020 7:55pm
It would take me 30 seconds per side to weld that shut in steel. I promise you wont break it again, . Ever,., .I would use a stick, and it wouldn't be pretty and shiny, with zero splatter, but would look and be very strong.

I could mig it, I could tig it, if you wanted zero splatter and perfect half-moon dimes laid upon each other.. but that costs gas and consumables and .. time for setup and good control of the weld with the mig or tig.. time... So I would probably go to the stick first. I would stick weld it in literally 60 seconds for free. Lol. You wouldn't be able to break the joint swinging a 10lb sledgehammer on a three foot handle as hard as you can, John Henry style.


I mean, yes, I suppose you could mess it up ( the weld), but plain ol regular low carbon steel is usually very forgiving and easy to put back into service without much downtime.

That crack was not cycling fatigue, it is stressed.., torn... over-bending backward I would bet. I bet you could even braze it if you took the time to prep and close the joint as much as you can, then braze reinforcement over it.
You're not near Brooklyn, NY, are you...? :wink:

So you think it's just the one tear and that there's not likely to be other small cracks that will worsen with time? Definitely not planning and fancy/ hard riding with it, just something for my daughter to ride on family fun rides or if we're going someplace by bike.

I brought it over to a welding place here to get an estimate, but the guy wasn't there today. Should call me back tomorrow, hopefully. I called nakto about getting a replacement frame. They said they happen to have one available, would be 75 with shipping. Im hoping the welding will be far less than that, though, although I really have no idea how much something like that goes for.

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Re: crack in frame. salvageable?

Post by markz » Aug 04 2020 10:55pm

Returnformer wrote:
Aug 04 2020 9:02pm
I brought it over to a welding place here to get an estimate, but the guy wasn't there today. Should call me back tomorrow, hopefully. I called nakto about getting a replacement frame. They said they happen to have one available, would be 75 with shipping. Im hoping the welding will be far less than that, though, although I really have no idea how much something like that goes for.
I would buy that bike for 75 w/shipping, if you really want it or its something you think you will want in the future, but having 2 of the same bike its up to you. The welder will probably charge a minimum charge of $40, time to weld, a 1/5'th of a rod, gas, all the all important setup position which takes time.

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Re: crack in frame. salvageable?

Post by Returnformer » Aug 04 2020 11:49pm

markz wrote:
Aug 04 2020 10:55pm
Returnformer wrote:
Aug 04 2020 9:02pm
I brought it over to a welding place here to get an estimate, but the guy wasn't there today. Should call me back tomorrow, hopefully. I called nakto about getting a replacement frame. They said they happen to have one available, would be 75 with shipping. Im hoping the welding will be far less than that, though, although I really have no idea how much something like that goes for.
I would buy that bike for 75 w/shipping, if you really want it or its something you think you will want in the future, but having 2 of the same bike its up to you. The welder will probably charge a minimum charge of $40, time to weld, a 1/5'th of a rod, gas, all the all important setup position which takes time.
well, thats only the frame, so it wouldnt give me two of the same bike. i would have to move over the wheels and everything from this one.

40 would be much cheaper.

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Re: crack in frame. salvageable?

Post by Returnformer » Aug 05 2020 2:34pm

markz wrote:
Aug 04 2020 10:55pm
Returnformer wrote:
Aug 04 2020 9:02pm
I brought it over to a welding place here to get an estimate, but the guy wasn't there today. Should call me back tomorrow, hopefully. I called nakto about getting a replacement frame. They said they happen to have one available, would be 75 with shipping. Im hoping the welding will be far less than that, though, although I really have no idea how much something like that goes for.
I would buy that bike for 75 w/shipping, if you really want it or its something you think you will want in the future, but having 2 of the same bike its up to you. The welder will probably charge a minimum charge of $40, time to weld, a 1/5'th of a rod, gas, all the all important setup position which takes time.
he wanted 75 to weld it, so im gonna go with the frame.

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Re: crack in frame. salvageable?

Post by Balmorhea » Aug 05 2020 3:12pm

Keep the fold joint good and tight, or this predictable failure will happen again. It might even if you do.

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Re: crack in frame. salvageable?

Post by markz » Aug 05 2020 6:15pm

Returnformer wrote:
Aug 05 2020 2:34pm
he wanted 75 to weld it, so im gonna go with the frame.
Yeah pro's always want a lot of money for their work, lots of unemployed welders out there will do it for cheaper. Online classifieds would be the place to look.

But just pay for shipping for that frame and swap everything over.

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Re: crack in frame. salvageable?

Post by Returnformer » Aug 06 2020 9:30am

markz wrote:
Aug 05 2020 6:15pm
Returnformer wrote:
Aug 05 2020 2:34pm
he wanted 75 to weld it, so im gonna go with the frame.
Yeah pro's always want a lot of money for their work, lots of unemployed welders out there will do it for cheaper. Online classifieds would be the place to look.

But just pay for shipping for that frame and swap everything over.
yeah. actually, now that you mention it, i remember seeing someone advertising welding in the bicycles page on craiglist, i wonder if he would have done it cheaper. not sure how close to me he was, tho. and i already ordered the frame. oh, well, itll end up costing 250 overall, which is still a good deal for an ebike.

i imagine it should be fine under the light usage itll be getting, but illl keep an eye on the new frame in case it cracks as well.

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