Is my frame ruined?

godwit

Hello,
I need some advice from a framebuilder! I discovered this dent on my LHT while loading it on my bike rack
5/2/08. I parked my bike at work (inside the lab where I work) and
didn't notice it when I left. I don't know if someone knocked it over,
hit it with something or if my frame had a defect. The frame is made with 4130 cromoly. Is this bike safe to ride? Is my frame ruined? I feel ill every time I look at it.
I posted some pictures at :
http://picasaweb.google.com/senorblue/LHTDent

Mike Blue
Renton, Wa

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Peterpan1

I don't think that's a problem. I definetly don't think it's a flaw. That is a blow or crush to your top tube, and it would take a bit to do that. I think it is also pretty unlikely that you would have missed that for a moment. It probably happened just before you first noticed it.

I doubt it would collapse just from riding. The top tube is mostly under compression, and a dent like that is a bad thing in that case, it's like standing on a beer can, and then dimpling the side and it collapses. But I think your dent is probably surviveable. You could write Surly.

It might be possible to pull that out with a stinger, but who could you get to do that? Maybe an autobody place would try. The sheet metal they work with is about the same as tube wall. I think the tubes on a Surly are butted which would be probably .6mm in this case.

Peterpan1

http://frameforum.org/forum3/index.php?topic=393.0

Torchy McFlux

Dents like that can be easily popped back out in most cases. CrMo is strong and can take a few knocks - I wouldn't worry about it.
You clamp some aluminum or hardwood tube blocks with a bench vise around the damaged area, tighten lightly, rotate the frame in the blocks, tighten, rotate, repeat until the dent is pretty much flush with the rest of the tube. Some silver braze will fill in the remainder of the dent, which is filed flush. Repaint, and if it's done well, no one will ever notice.

Sirrus Rider

Hello,
I need some advice from a framebuilder! I discovered this dent on my LHT while loading it on my bike rack
5/2/08. I parked my bike at work (inside the lab where I work) and
didn't notice it when I left. I don't know if someone knocked it over,
hit it with something or if my frame had a defect. The frame is made with 4130 cromoly. Is this bike safe to ride? Is my frame ruined? I feel ill every time I look at it.
I posted some pictures at :
http://picasaweb.google.com/senorblue/LHTDent

Mike Blue
Renton, Wa

I'd look for the Yahoo who dropped his bike on yours.

Torchy McFlux

I'd look for the Yahoo who dropped his bike on yours.

Looks more like someone knocked it over and on its way down hit the edge of something. One of those toptube pads the hipsters use could have been useful.

Powerarranger

Dunno if this will help, but in the world of brass instrument repair there's a thing called 'The Dent Eraser'. The technician runs a spherical mandrel of the proper size through the tube to the dent location, then takes a powerful cobalt magnet and rubs the dent out from the inside. This technology is also used (on a larger scale) to repair airplane wings which get damage from bird strikes. These magnets are VERY powerful and might be able to generate enough pressure to iron out a dent in CroMo steel.

JBD

I'm curious as to how effective the magnet would be as the frame is ferrous, wouldn't it be a pain to have the magnet pulling on both the mandrel and the tube?