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MotoIdaho

Sorry about the delay, but other small things, like work interfered. Here are the pictures of the dent, in a valuable (to me) steel frame that I would like to save.

Here is a crazy idea, if I removed the stem and the seat post, I think I would have access to both ends of the top tube. Why not attach strong cables to a steel ball of appropriate size, and run it through the tube with a cable attached to each end, and use it in a dental floss action, and strike the dent from the inside of the tube?





The dent was from a recent "fall over" incident in which my wife hit a curb, and "fell over", so I can't yell at her too much.

Shimagnolo

There probably are holes drilled in the head tube and seat tube inside the ends of the top tube, and they are probably a fraction of the diameter of the top tube. Pull out your seatpost and take a look.

LarDasse74

When a frame is made the ends of the top tube are left open and attached to the head and seat tub - where holes are usually drilled, but the holes are smaller diameter than the ID of the top tube. It may be possible to get a steel ball on a a cable in there, but it won't be a ball anywhere near the ID of the tube. For this to work you would have to apply a large force to the inside wall of the tube, and it is impossible to apply a lateral foce with a cable (you can't push a rope).

If I were the OP, I would get the alignment checked by a compentent shop or builder - if the alignment is good then no problem. If the alignment is off then bend it back to straight.

When I first started racing mountain bikes, I was given a medium-lightweight steel frame with a large dent in the top tube (tube actually bent at the dent). In my teenage wisdom I decided the way to fix it was to hit the frame with a 10 pound sledge hammer to put an approximately equal dent in the other side. The frame straightened out and I raced that bike off-road for two years, and it still exists today as a cruiser bike at my camp. There was never any hint of a crack or buckling.

Deanster04

Dents in steel bikes aren't usually a problem. Actually a "dent" can give form stability to a round tube. Take some of the Colonago steel framesets. I would say that you could safely ride your bike for some time before you have to worry. But the picture shows a significant "crease" dent orthogonal to the tube. A significant sideways impact would cause a problem. I think it will eventually crack due to corrosion. Apply some paint and ride it until you want to replace the tube. This is an older steel frame and is fairly thick tubing compared to some of the recent frames. A good thing is that it is a lugged frame and the top tube can be replaced easily. It would probably cost $200 to replace the TT and some $$ to repaint the TT and areas around the lugs. Check with a local builder of contact Nobilette (Longmont, CO) or Bilenky (Philly I think). They can do very good frame repairs.
Forget the steel ball idea. Frame alloys for steel bikes have a very high modulus and aren't easily repaired. The steel on autos is very soft comparably. There is a set of rollers that can be used to roll out some of the dent's flare but, there will be some paint damage and the crease will remain. If you have a good frame builder in your area take the bike by. This is the time of year that builders can get to repairs because the new bike orders are down.

I recently dented the down tube of my Columbus Neuron (lightest of all steel tubing) in a crash. It is on the bottom of the DT so I don't see it (out of sight out of mind). The bike is a Mondonico Diamond Extra moltini orange. I will eventually replace the down tube and put in S&S couplers in for traveling. I am going to wait until it needs a paint job. Right now it is still beautiful.
I am not worried about the dent and would use the bondo route if I wanted cosmetic perfection. The paint wasn't damaged. I just wax my frames periodically to prevent any problems (and it makes the frame look nice). The frame alignment wasn't compromised and there are no twitches in fast descents so the frame is "good."
I recently sold an old 1999 Columbus FOCO tubing frame. The Shaped tubing makes for a very tough frame. It was thin but my Neuron tubeset is even thinner (and round). Unless the bike alignment or performance is in doubt don't worry. The only frames I have seen crack is from front end crashes where the top and down tubes are both bent across the whole tube diameter and the paint was compromised. I bought an old Torelli cross frame built with "seamed" tubing that was in a front end crash. I rode the bike for 3 years before I noted a crack in the tubing. I will eventually replace the tubes of the lugged cross bike when I have some Idle cash (a joke these days). Another nice thing about steel is that it will crack slowly and usually not fail catastrophically like Aluminum, Ti, or Carbon from a stressed frame. Ti is a very strong material but I have seen failure around welds from embrittlement caused by Oxygen during welding.

DannoXYZ 

Titanium is actually embrittled more by hydrogen than oxyen or nitrogen. It would have to absorb a lot more of those to get brittle compared to hydrogen. But yea, that's the idea.

As for the tiny dent in the top-tube, there's simply zero easy and inexpensive way to repair it. It doesn't pose ANY structural issues, so I wouldn't worry about that. Really, the ONLY way to repair that dent is to replace that tube with a new one. That means unbrazing all the tubes of the main triangle to replace it. I can do it for you as I've got all the equipment and built several frames for myself. I'll estimate about 10-15 hours @ 250/hr.

Torchy McFlux

I'm still going to say that that that dent can be mostly popped back out with some hardwood tube clamp blocks, a bench vise, and some elbow grease.
You clamp the tube over the dent, tighten the vise until you feel a decent amount of resistance, rotate the tube in the blocks by pushing/pulling the frame's downtube, tighten some more, rotate, etc. until the clamp blocks are completely bottomed out on the tube surface. The pressure on the high spots around the dent will force the tube wall to pop back out where it was indented.

Squeazel

+1, after looking at it. I'd give the blocks with a hole through them a try to get the tube round again, *then* bondo.

DMF 

I wouldn't touch it at all. Just ride it.

Torchy McFlux

Just noticed that your cable guide is probably behind that ruler. That puts it too close to the dent to allow you to clamp some blocks there. You'd need to have the guide properly removed to get the dent fixed. It could be brazed back on afterward.
Might want to call up a local framebuilder for an estimate to see if you think it's worth the expense.
That Fuji's toptube is tough enough. You'd be doing this primarily for cosmetic reasons.

MotoIdaho

Thanks to all for advice. I took the seat post out, and the hole leading into the top tube was only about 1/4". I may get the tube replaced someday, but for now the plan is to ride it, and fill it bondo it if I ever paint it. Thanks for the skilled analysis by all. Bob

RiceAWay

Without posting the picture first, the people here did not realize how bad it was, while I do not think that it seriously affects the strength of that Fuji, it is only repairable by a framemaker. I agree with the person who suggested replacing the frame. Craigslist usually has good frames in the bike parts section that are very reasonably priced. This falls under the heading of "**** happens" usually when you can least afford it. That appears to be a 56 cm frame, which is the most common size.


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FBinNY 

Why? Why? Why?
Why would you revive a 16year old Zombie thread to add this?

Atlas Shrugged

Let’s hope he had the opportunity to save up over the 14 years since he made this post.

cb400bill

Zombie thread has been closed.