Welding 6061 Aluminum Bike Frame with Crack: Expert Advice, Costs & Alternative Solutions

Some time ago I noticed that my bicycle frame (aluminum, alloy 6061) has a clear crack in the vertical part, almost in the middle of the joint.


On the bicycle forum, they advised me that the frame to be thrown away to buy a new one (the cheapest costs, already fairly decent, are about PLN 400-500).
Many people broke somewhere on the seat mounting - I understand there, there can be a large moment of force, but here it is more of a compressive than a tensile force.
In addition, none of the new frames was fully satisfactory for me (bad painting, hooks for mounting lines above the frame, and I prefer it under), which seemed the most reasonable solution when trying to weld for up to PLN 100.

I gave up for welding, I have already traveled a bit in especially difficult conditions and the crack does not seem to come out from under the weld, hence the question, has it been welded well? I gave 70 PLN for welding. I am a bit dissatisfied with this sanding over the weld (they probably sanded a millimeter of the pipe, instead of just removing the varnish) and in general, they did not handle the bike too delicately (paint splinters in several places).

I would not even pay a zloty for such welding. I am afraid that after a month of use it will crack in a different place (just above the weld).

It is pissed up, not shit up. If it was a real tig welding specialist, it would be completely different.

Samuraj wrote:

I'm afraid that after a month of use it will crack in a different place (just above the weld)

Don't be so forward. Why should it break just above the weld? The welds themselves are extremely unsightly. I have a suspicion that someone smacked with the electrode.

He flew in a jiffy. In fact, he was a snot. Well, for 70 zeta ... You would have to sandblast the place, wash it, cut the joint with a dremel and pour it nicely with a tig. I don't know if I would like to for 200. But now it's mustard after dinner, sprinkle some spray and ride it until it crashes.

kortyleski wrote:

Well, for 70 zeta ... it would have to be sandblasted, washed, cut with a dremel for the joint and poured nicely with a tig. I don't know if I would like to for 200.

Exactly the alu must be clean to weld, with the varnish welding is almost edge-to-edge.
You had to pull the stitches upwards to make them stronger.

So you worried me, I commissioned the welding company dobry-spaw.pl, they had 150 positive opinions (and no negative ones), and here is such a flower.
As for the price, is PLN 200 for something like that? I wonder what hour you have then.
And how much would it cost you to weld the entire frame from scratch ;)

I understand that the responsibilities include removing the varnish, degreasing, preparing the place for welding, but I am supposed to do it? This is probably the welder's duty. When I go to the hairdresser, should I also wet my hair myself and come wearing an apron?

phanick wrote:

As for the price, is PLN 200 for something like that? I wonder what hour you have then.

PLN 200 per hour in aluminum on own equipment

phanick wrote:

So you worried me, I commissioned the welding to dobry-spaw.pl, they had 150 positive opinions (and no negative ones), and here is such a flower

It looks like an apprentice is welding it, not a professional. Slagged glutes poured on, not properly melted into the material.

phanick wrote:

As for the price, is PLN 200 for something like that? I wonder what your hourly time is then.

Welding this tig takes about an hour of work - grinding old welds, chamfering cracks, sandblasting paint and dirt, welding only. It goes very slowly in regret - believe it.

phanick wrote:

how much would it cost you to weld the entire frame from scratch

Single? In the thousands. The very preparation of the instruments to make it work evenly takes a few days of work. For example, for making a steel frame for a motorcycle (custom bike) about two years ago I took a round tenner. No material costs. Polished acid

Honestly? I would not get on such a snotty frame. In the hole you will crack and you will lose your teeth.
Take this crap to the company that welded and get the work done and the frame broken.

These are the things that technical school students do in their first class.

Added after 3 [minutes]:

phanick wrote:

to the price is PLN 200 for something like that? I wonder what your hourly time is then.

The price is not excessive. You mainly pay for know-how, not for work. You want to save, you see what it looks like.

I have never seen a worse form of welding than here. I don't believe someone did it sober.

For this it is boiled, because the bearing in the bottom bracket has not been removed before welding ...

My first welds in MIG steel looked better on an uncleaned surface ... I think these opinions were paid, some kind of massacre. I would go there for a refund for lost time and a damaged frame.

But it wasn't even disassembled for welding! You can see the molten grease from the bearing. Tosz, you need to remove all the equipment, sandblast it from the paint, as colleagues wrote, make a wedge into the old weld so that it floods inside. It doesn't last an hour, but it doesn't cost PLN 100.
Here, a welder, when he used to weld in aluminum, put details into a pool of water and they protruded 1 cm above the water and welded there for better cooling. I don't know much about welding there, but it gives you an idea of what aspects you should pay attention to.

I see that many people repeat what was written in the post # 2, # 3, # 4, and I will add that it is really tragic and I would not give a zloty for it. I am writing to make sure that the author after these # 14 posts about the same well understood the seriousness of the situation and the quality of the service ...

And secondly, if it broke, it should be looked for elsewhere also because the frame is a cage and the stiffness of the frame corresponds to all the arms.
There is also something wrong with you.

phanick wrote:

So you worried me, I commissioned the welding to dobry-spaw.pl, they had 150 positive opinions

I'm not a welder, I don't know myself. I also had welding at one time. But I have never seen anything like you showed.
It was done to me by a one-person bet, a small workshop and he did what he should, because what you showed I would not call a weld.
If this is true what you write then leave them a relevant opinion with a link to the electrode and pictures. They even have an account on FB.

Gentlemen, welding for PLN 70 and you want it to look like a robot is welding. The photos enlarge and exaggerate it a bit. You can see that it is welded and not just poured. The aesthetics are so-so, but in such a place for PLN 70 I would not require anything better.

Ok thanks for the comments.
The entire welding frame was disassembled by me practically to zero (removed support, i.e. bearings and bowls), derailleurs, wheels, saddle. I only left the shock absorber at the front with the handlebars, so access to the welded area was perfect.

So far, the frame is holding somehow after another quite demanding rides, the crack does not seem to come out, nothing creaks. What I would stick to at the beginning is that in one place (at the back of the seat tube) they should weld 1 centimeter away, because not the whole crack was covered with a weld.

I understand the remarks that some would not start for less than PLN 200, in another establishment, before returning it, I asked about the price, they sang PLN 300. I understand that professionals appreciate them, but then maybe let's get down to earth, who then welds these frames in factories that do not cost a dozen thousand?

Somewhere I read that when it begins to crack, it is worth drilling this place, then we make it difficult for the crack to expand further.

The bike was 10 years old, there were different loads, rides and after 35 km / h on the hills and lows, there could be some material fatigue. I remember that around those days, when I found the crack, a week earlier my rim in the front wheel broke a bit (but it was already worn out with blocks for a long time), so probably on that fateful day the bike got some strong force down and it came out weak points.

phanick wrote:

Ok thanks for the comments.


I understand the remarks that some would not start for less than PLN 200, in another establishment, before returning it, I asked about the price, they sang PLN 300. I understand that professionals appreciate them, but then maybe let's get down to earth, who then welds these frames in factories that do not cost a dozen thousand?

They already have templates, clamps and devices, put the pipes in their place and weld quickly

phanick wrote:

Who, then, welds these frames in factories that do not cost a dozen thousand?

Robot or full-time people.
They weld one thing all the time. Tubes come up, you take it on the table, put it in the machine and weld it.

telecaster1951 wrote:

Robot or full-time people.

A colleague worked in a bicycle factory, only welding robots. At least with them.

You should pay 70 times in RYJ for these welds, not 70 zlotys. You have the right to demand a new frame from Him, because He destroyed the other.
And it's not about price for quality. Either I weld (given metal) or I don't weld. And I do not want to offend anyone - trash.

ziemek56 wrote:

You should pay 70 times in RYJ for these welds, not 70 zlotys. You have the right to demand a new frame from Him, because He destroyed the other.

Tap on your head - you have the right to do so too.

Sorry, but Human Life may be hanging on these welds. A RYY HAS A NOT THINKING PERSON. Thank you.

ziemek56 wrote:

Sorry, but Human Life may be hanging on these welds. A RYY HAS A NOT THINKING PERSON. Thank you.

Then report it to the prosecutor's office as an attempted murder. This is an ex officio crime, so anyone can submit a report.

I must be unlucky because I noticed a second crack in a completely different place. In addition, the bicycle seatpost is also damaged in a strange way (I bought a longer one to make it fit into the frame at the right depth). I wonder how these 100-120 kg cyclists ride like in my case at 65 kg, such miracles happen ;)

phanick wrote:

I must be unlucky because I noticed a second crack

You have a low-quality frame and that's it. Maybe it has a lot of stickers and in papers, space technologies and aluminum alloys, but in fact it is probably not the case.
Or you torture the bike extraordinarily and the frame is not meant for it. Basically, aluminum is stiff and prone to cracking like this. Do you have a stiff fork or a suspension fork?
I use a steel frame, now it is about 15-18 years old. I weigh 90 kg.

phanick wrote:

I wonder how these 100-120 kg cyclists ride like in my case at 65 kg, such miracles happen

This frame has manufacturing defects. Cracks at the weld seam, which means that either the material was wrong or the weld was defective. Ergo frame for scrap metal.