Broken frame, need advice
 

I bought a bike frame, with several components(not complete bike), bought it more for the parts, but I really like the frame.
My question would be it can be repaired? and if it is repairable, worth it? and will be safe the frame?
The frame is a Mercier aero frame.
Thanks

Can't say I have ever seen a head tube like that... Do you have the fork?

Junk. Toss it and move on.

To elaborate: it can be repaired by replacing the cracked tube with a new one. Typically this repair costs $200 and up, not including new paint, which is another $400+ dollars. So unless the frame is quite valuable or has sentimental value, it is rarely worth it.

Also, if this is a TIG welded frame, then it cannot be repaired at all. (I can not tell from the pictures)

Frame repair is prohibitively expensive if you want the end result to look decent. I agree with the toss it and move on remarks, you could use that money for so much more.

The only thing I'd use that frame for is to practice brazine on.

Yes i have the fork, and here is a link with a similar frame...

Mercier Formule 1 1980?- speedbicycles.com

Replacing the tube it is expensive, and I don't know where I can find a similar oval tube.
Whats means "TIG welded frame" ?
Thank you

Thanks for the answers.
Does anybody know if it is welded it will hold?

Tungsten
Inert
Gas

It's a welding process.

It looks like your frame is fillet brazed.

If it could somehow be welded, I would not trust it, even a little bit.

That frame is totaled.

I've long wanted to try to repair a cracked frame by sleeving the crack in carbon fiber. 30 mm overlap, 1-2 mm laminate thickness and you should be good to go if you've done the prepwork right and gotten good adhesion.
Two things comes to mind:
1) cracks like that tend to come from fatigue. How much life is left in the rest of the frame?
2) you'd need to lose the DT shifter bracket to be able to do the best possible sleeve.

Is that the downtube that is broken?

I've seen a few broken seat tubes, but I think that is the first downtube that is broken like that.

For a seat tube, I believe one could add a sleeve insert, and it could be welded or brazed to make a very strong joint.

The downtube naturally has less internal access. One could still make a reinforcement ring on the outside of the tube,and braze it for a visible repair, but it might not look bad, especially if you make it look like it is supposed to be part of the shifter block.

How is the shifter block attached? Brazed or welded?

You may be able to TIG weld the repair, although if the shifter block is brazed, you would risk contaminating the weld with brass, unless you're very careful with removing the block and cleaning the joint, welding then putting it back together (thus brazing an external ring onto the joint might be easier).

One of the issues is that some of the older alloys were supposed to lose some strength with TIG welding. You'll have to decide if that is acceptable. Also, with double butted tubing, the mid-tube thicknesses are paper thin making welding more difficult and weaker.

I'd encourage you to talk to a local bicycle framebuilder, or if you can't find one, even a welding shop (that can both braze and TIG weld) before you make a final decision on the frame.

Those drilled holes look odd. What was in them? If welding, however, they would be easy to fill.

Butt-Weld brazing would be weak, and would require a lot of material build-up around the joint. It could be done, but wouldn't be my choice.

Brazing an external ring or sleeve over the crack might be the strongest, and nearly as strong as a typical lugged frame, except that the tubing is thinner mid-tube.

If a good TIG welding job is done, it will weaken the metal slightly near the weld, and the metal is very thin, so it is hard to say.

I wouldn't invest a fortune on restoration in case the crack would reappear, or other stresses are found, but you might get a good rideable frame.

The crack seems to have been caused by the welding on of the aero shifter mount on top of the down tube. Must have overheated the tube and weakened it. Also looks like the frame led a very hard life, judging from its overall condition.
It will be quite a noble effort to resurrect the frame. Lots of work and expense, so be careful you do not put in more than the frame is worth, unless maybe there might be an important personal, sentimental connection you might have with it.
BTW, I think I've seen a similar head tube on an aero style Gitane frame......

The failure would appear to be fatigue resulting from overheating during brazing of the shift levers ' boss. This would be in the thinner 0.6mm section of the tube. The downtube appears oval, so the only practical repair is replacement of the tube by a competent framebuilder experienced in fillet brazing. This is not going to be cheap and a standard tube may have to be formed to get an aero profile similar to the original.

Yes the dowtube is broken, but I think that somebody fell down with the bike, or something hit the downtube on the left side which caused the rupture. I upload two more picture.
Reinforcement ring may be complicated because the tube is oval.
The frame is VITUS 980 DOUBLE BUTTED.
Somebody tried to repair the frame with a piece of sheet and four screws.

I don't know if the fatigue or something hit the frame, and caused that rupture.
The tubes are oval.

Here is a link with a similar frame..
Mercier Formule 1 1980?- speedbicycles.com

Do you have the seatpost that goes with the frame? I'm not quite sure what that black band is on the linked photos. Tape? Does it use a quill/internal expander to hold it in place? That could be one part that would be really difficult to find if you don't have it.

It is hard to tell if the seat tube has been damaged near the top.

I still think one could make a ring to go around the outside of the tube, maybe using heat to help form it, then brazing it into place. You'll lose some of the original clean lines, but it might not look too bad if done well.

Replacing the tube wouldn't be for the faint hearted, but would theoretically be possible.

I'm seeing a couple of companies that make oval and teardrop chromoly (4130) tubing.
Streamline and Oval Tubing Suppliers - ProFormance Metals
Unfortunately, I think it is all straight tubing (.035 or .049).

However, if they do custom fabrication, they might be able to shape commercially available round bicycle tubing. Or, if your tubes are a true oval and not a teardrop, I wonder if they could be flattened between two steel bars/plates, or even wood boards using clamps or vises.

As others have mentioned, the true commercial cost of the repairs will be very high depending on how you choose to do it, and you still end up with a repaired/repainted frame that some people will shun. But, if you do it yourself, or find a friend of a friend to do it... perhaps it could be done at a reasonable cost.

I would suggest asking to get this discussion moved here. Don't start a new topic, just click on the "Report" button.
Framebuilders - Bike Forums

Yes I have the seatpost, it is an internal holder seatpost (similar with the stems). The black band I think it is a rubber ring (unfortunately didn't have it).
Thanks for the replies

If you have unlimited time and financial resources why not if you have an emotional bond to that frame.

Personally, I try not to have emotional bonds to cold metallic objects, so parting with them for the most part is fairly uncomplicated.

Personally I enjoy "projects" and vintage stuff. Although it is easy to get too many projects.

The bike world is interesting, perhaps a lot of things are like that, but the raw materials to build a new frame from scratch (retail) cost more than purchasing a complete vintage frame.

This Mercier Aero frame appears to be quite unique, and far better than an Aerowind. So it may well be worth "saving" if done for a reasonable cost.

There is apparently one on E-Bay now though.
Mercier Formule 1 Aero Super Vitus 980 Arabesque Campagnolo Bicycle Vintage Velo | eBay

So, other than frame size, that puts an upper bound on the value of the frame/bike (unrestored).

Fix it for $100, and it might be worth doing. Fix it for $500, and one might as well just buy a different bike.