Another Dent Thread. Safe or Not?
08-08-23, 09:03 AM
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Another Dent Thread. Safe or Not?
A friend of mine has a beloved old road bike he uses as a commuter. Locks it up and leaves it all over Chicago and Manhattan. Recently, somebody put a lot of effort into stealing the bike and bent and dented the frame in the process. He says the front wheel rubs the frame now. I advised him to make wind chimes out of the frame and we'll find another commuter for him. He loves the bike and wants to hammer it back into shape and continue commuting on it. He studied as a mechanical engineer, so he's got some knowledge related to what he wants to do. Still, this sounds like a terrible idea to me. What do you say? I'll pass on your comments to him. Here's some photos of the bike.
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Last edited by Sedgemop; 08-08-23 at 09:42 AM.
08-08-23, 09:24 AM
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If the front wheel is rubbing the frame, it's so outta whack that it might take a framebuilder to fix it. If the rest of the components are in good shape, I'd tell your friend he should just find a new to him used frame.
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08-08-23, 09:32 AM
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As I learned from another mechanical engineer (whose initials are @gugie), “Safety third!”
08-08-23, 09:33 AM
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Since he is studying mechanical engineering have him investigate what happens to a tube when it is not longer in a “tube“ shape as well as the forces on a bicycle downtube. A tube with a kink in it like this one won’t stay straight too long. Given that the front tire is rubbing on the frame, there is severe bending of the frame as well. Time to find a new frame.
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08-08-23, 09:45 AM
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Yeah, the frame bend concerns me at least as much as the dent. Had already mentioned the framebuilder possibility and that might be the happy compromise since he really doesn't want to give up the frame.
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08-08-23, 09:52 AM
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As I learned from another mechanical engineer (whose initials are @gugie), “Safety third!”
https://www.dischord.com/release/ec703/safety-fifth
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08-08-23, 09:55 AM
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08-08-23, 09:58 AM
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It sounds like your friend enjoys a challenge.
What is the make and model of the damaged?
Your friend can, if he desires, rollout much of the denting with a removable stem-matching diameter. The bend can be addressed as well with a heavy clamp a half moon block and some wood. If he really wants to bring that one back. Some would probably say that tube needs to be replaced.
Even with a higher value frame sentimentally it's probably not worth the efforts.
What is the make and model of the damaged?
Your friend can, if he desires, rollout much of the denting with a removable stem-matching diameter. The bend can be addressed as well with a heavy clamp a half moon block and some wood. If he really wants to bring that one back. Some would probably say that tube needs to be replaced.
Even with a higher value frame sentimentally it's probably not worth the efforts.
08-08-23, 10:05 AM
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It sounds like your friend enjoys a challenge.
What is the make and model of the damaged?
Your friend can, if he desires, rollout much of the denting with a removable stem-matching diameter. The bend can be addressed as well with a heavy clamp a half moon block and some wood. If he really wants to bring that one back. Some would probably say that tube needs to be replaced.
Even with a higher value frame sentimentally it's probably not worth the efforts.
What is the make and model of the damaged?
Your friend can, if he desires, rollout much of the denting with a removable stem-matching diameter. The bend can be addressed as well with a heavy clamp a half moon block and some wood. If he really wants to bring that one back. Some would probably say that tube needs to be replaced.
Even with a higher value frame sentimentally it's probably not worth the efforts.
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08-08-23, 10:17 AM
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This is not a dent in an otherwise straight tube, like when a handlebar comes around and dents a top tube. This tube is kinked, bent and deformed. The tube has also been gouged such that there are places where the tube wall is now thinner than it used to be. Considering that the tubing wall is somewhere in the neighborhood of 1mm thick. that strikes me as a Very Bad Thing. Your friend should not ride this frame again. Ever.
The two best options have been mentioned. The easy way is to buy another frame. The more difficult way is to have a frame builder/repairer replace the damaged (read: "destroyed") tube, which will also entail a repaint or powder coat.
It makes me sad and angry that some anus cookie destroyed a perfectly good frame solely to feed their greed and malice, but destroy it they have.
The two best options have been mentioned. The easy way is to buy another frame. The more difficult way is to have a frame builder/repairer replace the damaged (read: "destroyed") tube, which will also entail a repaint or powder coat.
It makes me sad and angry that some anus cookie destroyed a perfectly good frame solely to feed their greed and malice, but destroy it they have.
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08-08-23, 10:30 AM
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Safe or Not?
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08-08-23, 10:41 AM
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This is not a dent in an otherwise straight tube, like when a handlebar comes around and dents a top tube. This tube is kinked, bent and deformed. The tube has also been gouged such that there are places where the tube wall is now thinner than it used to be. Considering that the tubing wall is somewhere in the neighborhood of 1mm thick. that strikes me as a Very Bad Thing. Your friend should not ride this frame again. Ever.
The two best options have been mentioned. The easy way is to buy another frame. The more difficult way is to have a frame builder/repairer replace the damaged (read: "destroyed") tube, which will also entail a repaint or powder coat.
It makes me sad and angry that some anus cookie destroyed a perfectly good frame solely to feed their greed and malice, but destroy it they have.
The two best options have been mentioned. The easy way is to buy another frame. The more difficult way is to have a frame builder/repairer replace the damaged (read: "destroyed") tube, which will also entail a repaint or powder coat.
It makes me sad and angry that some anus cookie destroyed a perfectly good frame solely to feed their greed and malice, but destroy it they have.
Yeah, bent and dented is a bad combo. He doesn't know it yet, but the frame ain't making a comeback. Hoping he'll try a couple possible solutions that fail and then let me find him a frame.
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08-08-23, 10:41 AM
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So, good story. And we're still in the early phase of this fiasco, where the accident is just a theoretical, if likely, future event. So we can offer suggestions and say, maybe it'll be OK.
By the time the accident is in the past, I'll give it three weeks, your friend will be upgraded to "obvious numbskull," if not by us, then by the rest of the internet. "What was he thinking" the refrain will be, and really: what is he thinking? Where's the upside?
You could do him a service and suggest he get with a good dentist and an orthopedic surgeon now, and work out a discount and payment schedule. He'll need it, and he'll have other things on his mind after the wreck, so that's a win. Thinking that through might help him make the right decision.
I'm all for stupid ideas, don't get me wrong, but this one is above and beyond.
Junk it.
cheers -mathias
By the time the accident is in the past, I'll give it three weeks, your friend will be upgraded to "obvious numbskull," if not by us, then by the rest of the internet. "What was he thinking" the refrain will be, and really: what is he thinking? Where's the upside?
You could do him a service and suggest he get with a good dentist and an orthopedic surgeon now, and work out a discount and payment schedule. He'll need it, and he'll have other things on his mind after the wreck, so that's a win. Thinking that through might help him make the right decision.
I'm all for stupid ideas, don't get me wrong, but this one is above and beyond.
Junk it.
cheers -mathias
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08-08-23, 10:52 AM
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So, good story. And we're still in the early phase of this fiasco, where the accident is just a theoretical, if likely, future event. So we can offer suggestions and say, maybe it'll be OK.
By the time the accident is in the past, I'll give it three weeks, your friend will be upgraded to "obvious numbskull," if not by us, then by the rest of the internet. "What was he thinking" the refrain will be, and really: what is he thinking? Where's the upside?
You could do him a service and suggest he get with a good dentist and an orthopedic surgeon now, and work out a discount and payment schedule. He'll need it, and he'll have other things on his mind after the wreck, so that's a win. Thinking that through might help him make the right decision.
I'm all for stupid ideas, don't get me wrong, but this one is above and beyond.
Junk it.
cheers -mathias
By the time the accident is in the past, I'll give it three weeks, your friend will be upgraded to "obvious numbskull," if not by us, then by the rest of the internet. "What was he thinking" the refrain will be, and really: what is he thinking? Where's the upside?
You could do him a service and suggest he get with a good dentist and an orthopedic surgeon now, and work out a discount and payment schedule. He'll need it, and he'll have other things on his mind after the wreck, so that's a win. Thinking that through might help him make the right decision.
I'm all for stupid ideas, don't get me wrong, but this one is above and beyond.
Junk it.
cheers -mathias
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08-08-23, 11:15 AM
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Remember it is a steel bike.
That makes it fixable.
There can be so much fun resurrecting a beloved bike. Also, there is a great deal of pride in continuing to get good service out of a bike someone tried to take away from you...
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08-08-23, 01:15 PM
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08-08-23, 01:34 PM
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In that case it's simple. De-braze all the tubes from the lugs, dropouts, etc. Replace the old tubes and lugs with new tubes and lugs. Re-assemble. Paint.
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08-09-23, 04:00 AM
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Assuming the bike is made from gas-pipe or 4130 non heat treated steels, it may be possible to graft a new section into the down-tube. Your friend would need to locate someone skilled with a welder. The frame would remain bent until straightened.
As others have already stated, it's probably not worth the effort. I have a similar situation with an old Maruishi RX-5 frame that I used to enjoy riding around Florida. It's probably best turned into wind chimes or wall art, though, so I know the feel.
As others have already stated, it's probably not worth the effort. I have a similar situation with an old Maruishi RX-5 frame that I used to enjoy riding around Florida. It's probably best turned into wind chimes or wall art, though, so I know the feel.
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08-09-23, 05:57 AM
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Since he is studied in mechanical engineering he is ready to perform 'percussive maintenance' on the damaged frame tube...after all what could go wrong...
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08-09-23, 11:00 AM
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08-09-23, 12:44 PM
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It's fixable, but not in a "bend it back" way.
It's fixable in a replace the downtube, possibly the head tube and top tube, maybe even the fork. The fork and other tubes aren't pictured, so we don't know their condition.
The cost of repair and repainting would most likely far exceed the value of the frame, but sometimes love makes us do crazy things!
Even if he is willing to pay what it would cost, he may not end up with the same bike. Different tube thicknesses, butt lengths and even material may change the feel of the ride. The more tubes that are replaced, the higher the likelihood of something feeling different-maybe better, maybe worse.
It's fixable in a replace the downtube, possibly the head tube and top tube, maybe even the fork. The fork and other tubes aren't pictured, so we don't know their condition.
The cost of repair and repainting would most likely far exceed the value of the frame, but sometimes love makes us do crazy things!
Even if he is willing to pay what it would cost, he may not end up with the same bike. Different tube thicknesses, butt lengths and even material may change the feel of the ride. The more tubes that are replaced, the higher the likelihood of something feeling different-maybe better, maybe worse.
08-09-23, 01:57 PM
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Looking at how croooked and damaged is the down tube, I wouldn't even ride it. Even the shifters bosses are rusted and crooked. Your friend shouldn't ride the bike
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08-10-23, 07:04 AM
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I did some work years ago on Mechanical Engineering curriculumand we found an overwhelming emphasis on a deep understanding of physics, mathematics and materials for design, not the practical/real-world application of these in maintenance situations. A framebuilder could repair but why? Don't let him ride that bike as it is now.
08-10-23, 08:26 AM
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I did some work years ago on Mechanical Engineering curriculumand we found an overwhelming emphasis on a deep understanding of physics, mathematics and materials for design, not the practical/real-world application of these in maintenance situations. A framebuilder could repair but why? Don't let him ride that bike as it is now.
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