CuRed

Aluminum Vitus with downtube separating from the bottom bracket.
Jb weld or Gorilla glue?
I was also thinking of drilling and pinning it so that down tube cannot separate again.

Also the down tube shifter came off one side, again should I just glue it back on?

thanks!

rhenning

It was done originally with aviation epoxy glue. I suspect anything you try will not work well. Your frame may have become a piece of art to look at but not ride. Roger

miamijim

https://guywires.com/vitusmain.htm

Bianchigirll 

I agree do it right or don't ride it.

repechage

Not Gorilla glue. JB Weld is closer, but not the right material either, you really need some Aviation grade aluminum 2 part adhesive, in the epoxy family, but the mixing ratios of the high strength stuff are beyond JB Weld tech.
There are other things at play too, the joint must be super clean and of the right fit, too loose and it won't work for very long. I would go guywires or hang it. You might need a down tube.

CuRed

Thanks!
I guess this one is toast.
Was a co-op bike that I was naive enough to think would be an easy fix.
Might look nice on the wall.

ColonelJLloyd 

If it were mine and would otherwise be FUBAR, I'd use JB Weld. I've repaired farm implements that saw heavy use with it.

clubman 

Marine epoxies are also outstanding and designed to bind metals, fiberglass, composites, etc...

https://www.westsystem.com/ss/

edit aircraft too.

Jeff Wills

That page hasn't been updated in 4 1/2 years... but maybe they're still around.

IIRC, Havnoonian: https://hhracinggroup.com/ and Open Road Bicycles in Pasadena: https://www.pasadenaviews.com/day-102...-bicycle-shop/ know how to repair Vitus frames. Separation of the seat tube at the bottom bracket was common until they got their adhesives and processes worked out.

David Newton

If one joint is loose, all the joints are compromised.
If it were mine, I would take it completely apart with a heat gun, and build it back with JB Weld.
JB Weld is probably better than what they used originally, but you have to get the old glue cleaned out before you re-glue.
If you use the long-set JB Weld, you can heat it up with a blow dryer and it will flow a lot better than cold, but you have a shorter working time.

mudboy

I remember speaking to Jock Boyer at the new york bike show back in the day, shortly after I got my Motobecane Prolight. He was riding a Vitus, too, and said that when the frames came undone, the mechanics just heated the joint up with a heat gun and shoved them together again.

unworthy1

That won't work with epoxy: it's not a thermo-plastic resin, heat will not melt it again...enough heat will actually burn it. I like JB Weld just fine as a hardware-store epoxy, but I would NOT trust it for a structural repair like a bicycle frame (let alone an airframe!) If you want to experiment (and treat it as experimental, it might fail at any time) I'd get some really serious high-peel-and-shear-strength industrial epoxy (and clean the bejesus out of the joint before applying)...it might even be more like the stuff that Bador SHOULD have used to assemble the Vitus frames from get-go.
Since I'm in a ranting mode, I just can't resist saying that I have never found Gorilla glue to be good for ANY repair, and I do a LOT of wood gluing. YRMV.

753proguy

That sounds cool, but that website hasn't been updated since 2007....

Chombi

Early last year, I shot out an email at the address indicated on the site asking about replacement Vitus declas and surprisingly, I still got a response from a person. I think the company is still alive in some form but much abbreviated to just selling off any left over parts they still have, They/the person who answered my email might still be able to help the OP. The knowledge and methods to repair Vitus frames just don't go away and some of these guys might still be willing to do it for people that will pay.
By the way, No more Vitus decals are available fromGuywires.....

Chombi

prettyshady

I also have a vitus which needs a reglue. Its a carbone 3 and the reglue is by the rear derailleur so its not dangerous.

The previous owner had tried a re glue which has failed.

Looking for a way to mend it, but its at the bottom of the projects list.

Chombi

Hearing all the time that "Aerospace" glues were used on these bonded frames, maybe there's another knowledge base and repair soruce available out there. Do some ultralight aircraft aluminum airframes similarly get glued together in some way into joint lugs?? Seems like that route might be worth checking out.

Chombi

Jeff Wills

Yes, but there's plenty of information available on the Interpile about epoxies and metal-to-metal bonding. IMO, the tricky part about the OP's repair will be getting the parts separated, cleaned, and put back together in correct alignment. That's why I was pointing to the people that used to repair these frames.

Captain Blight

I beg to differ-- epoxy loses almost all its strength at about 150-160* C. I've taken misglued wood joints with a heat gun, re-aligned and clamped correctly, and had excellent results. So no, it's not a thermoplastic-- but heat will work.

I'd give it a try. You can pick up good 2-part epoxy at any West Marine store, and if you were willing to wrap the joint in a layer of carbon fiber, you'd probably ADD strength.

David Newton

If they had used a filled epoxy like JB weld originally, none of these "aircraft epoxy" assembled frames would be failing now.

Jeff Wills

Wrong. The reason epoxied joints fail on Vituses (Vitii?) is that the flex in the joint allows corrosion to happen in the epoxy/metal interface. Eventually the joint fails when there's not enough glued area to keep it stuck together.

David Newton

See? The failure scenario you note would be solved by the use of JB Weld.

unworthy1

that's news to me...I always assumed it was a heat-setting resin (albeit using a chemical catalyst for the "heat") and behaved like other heat-setting resins.
So, if 150-160C (that's around 300º+ for us in Fahrenheit-land) can melt it and it re-hardens...sounds just like a thermo-plastic resin to me. Or is there something else besides "melting" taking place?

septacycles

I had a vitus frame a while back that one of the seat stays separated on. I research repair and found a few people who repair vitus frames but in the end decided it wasn't worth the money since the frame didn't fit. I sold the frame as is with full disclosure to someone who wanted to try and do the repair them selves. Not sure how it went. The tricky thing with the repair was finding a glue/ epoxy that worked on aluminum to aluminum bonding. It all depends if you want to take the risk of repair your self and riding it.

jyl

Wouldn't drilling and pinning each tube in its lug largely remove the risk of a sudden catastrophic failure? The tube can loosen if your epoxy repair fails, but it won't suddenly separate.

Chombi

Alan pinned their bonded Al frames. If one can copy the way they do it, that could work out great, but don't expect to ever sell the frame as nobody will trust anything different from what was originally done by the manufacturer on the frame.
As already mentioned, corrosion between the aluminum and the glue is what usually causes the bonded frame joints to fail. I suspect if the owners avoided putting away their bonded frame bikes wet, they can avoid these problems. Any time you see a sort of blackish stain or tendrils at the bonded joints, it can be suspected as corrosion and one should avoid buying such frames.

Chombi