I have just bought a secondhand bike frame from ebay....and the previous owner has drilled three small holes spaced out along the cross bar,and someone told me the frame is now a right off cause of these holes as they could cause a fracture along the cross bar at some time causing the cross bar to fold ??? is this true ??? also the courier has dropped the frame onto the top of the seat tube bending it over...so i could not attach the seat rod....i tried to straiten the aluminium but i was careless and i now have approx a 6mm rip in the back of the seat tube...should i saw off about 6mm off the top of the seat tube ???? please could you advise on these problems.
Carrera Vulcan e bike frame problem
- Thread starter daverave
- Start date
The holes in the crossbar shouldn't be a problem. People are always drilling them to fit batteries and things like that. I never heard of a crossbar folding. That's just theoretical shite that people say, just to sound clever, like when they try to tell us that a frame will break because we stretched it to fit a motor in.
The seat-tube can probably be solved with a long seat-pin if you can find one the right diameter. You can get them up to about 18" long or even longer for folding bikes. Get one that goes right down to the bottom bracket. You can cut the end off if too long. There's sometimes a recess at the top of the seat-tube for the clamp. If you cut anything off a toplike that, you'd have to make a new clamp arrangement, like file the slot longer.
For future reference, aluminium work-hardens when you bend it. Before straightening, you should heat it up to anneal it, then it will bend easily for a bit until it work hardens again. Repeat until it's bent to where you want it. You can feel how far it wants to go. Never force it. Copper is the same, but normal steel doesn't have that problem.
Amateur heat treatment of an aluminium bike frame is something I would avoid at all costs. You have absolutely no way to understand the consequences, and a frame failure could be fatal.
The alloys and manufacturing processes are the result of very careful design and engineering, and aluminium is unforgiving, unlike steel.
Scrap it.
The alloys and manufacturing processes are the result of very careful design and engineering, and aluminium is unforgiving, unlike steel.
Scrap it.
Seat-pin is the tube attached to the saddle that slides up and down in the seat-post until you clamp it with the seat clamp. Some people call the seat-pin the seat-post, and some call the seat-post the seat-tube.
As you can see there are holes in the cross bar & the damage to the seat tube....i always have my saddle right down so no need to adjust it so can i just use the saddle pole clamp over the break or should i saw about 6mm off the seat tube....at present the clamp will not fit over the aluminium seat tube....can i use this bike safety with the holes in the cross bar and the damage to the saddle tubing ????
