frame damage

as246india said:

having disembarked from a flight on saturday i found that my bike had been squashed in it's bike bag, and the tube going from the rear mech to the seat post has been bent inwards. i think my frame is steel-cromo alloy. can anyone venture an opinion of likelihood of successful repair? i rang a frame-builder, and they said they wouldn't attempt the repair, as it would weaken the load-bearing capacity of a crucial part of the frame. in addition, has anyone had experience of claiming compensation from airlines (easyjet in particular)?

If the frame is steel, you have a much better chance of being able to bend it back to working condition. If the frame is merely bent, and there appear to be no creases or severe bends, then the procedure should be fairly harmless, and the result should bring the bike almost back to normal. If there are creases, it can be bent back, but the frame would be untrustworthy.

Also keep in mind that the parts of the tube that encounter the greatest forces are nearest the joints (i.e. the center of a tube under static stress encounters very little force). Therefore, a bend in the middle of the tube is much less dangerous than at the end of the tubes (hence why some tubes are butted or lugged near the ends of the tubes).

Please get professional advice. Without seeing the damage I cannot give my opinion of what you should do in your situation as there is never a stock answer. These are just some things to think about.

as246india said:

can anyone venture an opinion of likelihood of successful repair?

Define successful. Do you mean good as new, or good as in not immediately disastrous? Is the tube deformed in its cross section as well, or is it a smooth bend? Steel tends to lose a bit of its strength when it's bent while cold, and the sharper the bend the more strength is lost. Usually (as when spreading frames) we get away with it because the item is overdimensioned to begin with and can stand to lose a little strength.

If it's a smooth bend it can probably be straightened out, and with luck the rear wheel will still track as it should.The bike should not immediately fall apart on you, I've ridden years with bikes that had similar damages. But by definition it will weaken the frame, whether enough to be critical or not I can't say.

If you want to play it safe you scrap the frame.
If you're a bit daring you do the repairs and ride carefully and attentively.
If you're ready to spend some money, find a framebuilder who can graft a new rear triangle onto your frame.