Repairing a bonded frame

[henrysthreeironbands]

I have a bonded frame which has slightly separated 0.5mm at the headtube / downtube junction. Does anyone know if it can be fixed, and if so how?

 

[Woz]

Pictures?

Pretty sure the general consensus is no, not worth it. Have a wall hanger and have peace of mind to ride another day.

 

[ishaw]

I don't see why not. People repair bonded carbon and ti hubs and pace fork dropouts so the process and principles would be the same.

Nothing is impossible, just need to find the right person or process and tackle yourself if confident enough for the latter.

 

[mdvineng]

Search 3M website for suitable adhesives. Cleanliness of preparation is paramount.

 

[Woz]

I don't see why not. People repair bonded carbon and ti hubs and pace fork dropouts so the process and principles would be the same.

Nothing is impossible, just need to find the right person or process and tackle yourself if confident enough for the latter.

No. Triangles typically need a special jig, and usually all the tubes are pushed together in a co-ordinated fashion. When one bond fails, it potentially means all other tubes need to be debonded and cleaned for a proper re-assembly from scratch again. Some bonds can be internal or external to the tube / lug interface, or a bit of both. Pictures will help, but I hold no hope without a specialist for the moment.

Hubs and dropouts don't need this, just some sort of linear compression like a G-clamp is probably good enough during curing period.

 

[bikeworkshop]

Argos Racing Cycles have repaired failed bond joints, and can probably inspect the rest of the frame at the same time.

 

[Woz]

Argos Racing Cycles have repaired failed bond joints, and can probably inspect the rest of the frame at the same time.

That is proper advice I feel. When a headtube creeps a part, we owe it to the OP to take all the care necessary, because it is not like getting some contact glue and putting a sole back on a Nike trainer. I'm not scaremongering, but sometimes it's best just to say it was good while it lasted, regardless of brand, and almost regardless of time line.

 

[bikeworkshop]

Plenty of people have reglued a failed bond - I've done it myself - but the best way to minimise risk is to get it done by professionals with the most experience in the field.

They will be familiar with what stresses are acceptable, which brands and models are the most reliable, whether other factors might be at work before and after.

Plenty of people have had a nice looking steel or aluminium frame fail on them while riding. A lot of us own a frame we wouldn't ride down a mountain at 50 mph, for many reasons
I've seen fancy modern bikes broken within a few months of normal use.

Not sure I'll be riding a dyna tech fast ever again

 

[Woz]

I get what you are saying. I had a Miyata bonded frame that unbounded at the chain stays. I honestly thought about it since it was a beater bike, if I had to do a bodge job, I would have pushed the lot together with force via ratchet straps and drilled the lugs / tubes and pop-riveted the fcuker together again with my trusty Lidl kit to squeeze out a few more rides on the edge. I could only guess the end result in terms of alignment

It is the point though isn't it?

When there are so many good ..... errrmm .... frames out there for peanuts why actually bother? We all know these bonded frames have expired their warranty by a factor of god knows, and plus if you had one second hand you have no idea of the history. Let's not forget, it was a new technology back then with it's pit falls.

 

[henrysthreeironbands]

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