I have a bent fork and dented downtube on my Bianchi Volpe, which has a steel frame and fork. It is sort of a cross between a touring and cyclocross bike. I took it to a LBS for them to have a look. The fork looks like it is toast. There aren't a lot of comparable replacement forks with 1-inch steerers, but we could probably come up with something that works. However, the opinion of the LBS is that the frame itself is unsafe.

This accident happened when my front wheel locked unexpectedly when I was going around 20 mph downhill. Not sure exactly why - possibly an extreme event of cantilever brake shudder. I did not run into anything. I went over the bars, broke my helmet on the pavement, and also hit me knee pretty badly. I should heal ok.

In any case, I have to decide what to do with this bike.

The dent in the downtube may have happened when one of the fender stays got driven back into the tube. At first that's what I thought, but then again, there isn't really a dimple in the middle of the dent. There is more of a crease that goes straight across. You can see in the first picture that the stay isn't really aiming right at the dent.


In the second picture, there is a round chip out of the paint that looks like it could be from the fender stay. It's offset from the dent.


In the third picture, there is a line that could be a crack within the bare patch near the ruler. I didn't even see it when I took these pictures at the bike shop. I only noticed it when I started looking at the pictures at home, so I can't go back right now and verify that it is a crack.



This is from the other side:


I have a few more pictures from other angles that I can post if it might help.

I thought at first that the dent wasn't a big deal, but now I'm coming around to the LBS's opinion that I should find a new frame and transfer whatever parts I can. Any thoughts for or against this idea?

The fork is toast, though years ago we used to routinely save these. The real test is whether the steerer is bent or only the blades, but in any case, you're not likely to find anyone willing or able to straighten it properly.

The frame is probably OK and I wouldn't hesitate to ride it. The dent is in a low stress part of the tube, but even if it were a classic downtube buckle up near the headlug it would last for a long time (many thousands of miles). Eventually a crack may form but crack spreading is steel frames is a long slow process so you'll have weeks or months of notice. Odds are it'll last until something entirely else kills it off.

If it were my own bike or a family member's I wouldn't hesitate to straighten the fork (if the steerer isn't bent more than slightly), clean up the bike and keep riding it. I'd probably relegate it "B" status as a commuter or bad weather bike, or kill it off in cyclocross, not because of safety concerns, but fear of stranding if the end came far from home.

I agree with FB about the frame. Fork I believe is probably toast, considering how badly it's bent at the fork crown. The odds are high that the column is bent and the crown area is extremely difficult to bend back properly.

The frame is ridable and should last quite a while. You need a builder to say weather or not the fork can be straightened.

Why even trust a fork like that just get new one. If you can't get another bianchi fork. you may be able to get one from gunnar.

I also saw this one not bad for $50

fork

That is a pretty nasty dent, but since it's on the bottom of the downtube, it might be ok to ride. Keep an eye on it though.

Friend of mine wrecked his Volpe recently, but the fork was untouched. He still has the fork and it's the same color and everything.

I would be tempted to drill a hole opposite the dent in the frame and insert a nail punch through the hole and tap that ding out. Might even use some heat. Steel is a good material to work with. Don't heat it above 400 degrees C or you might affect the strength.

Yes, the fork is done for. The LBS said that they won't straighten it for me. I could shop around, but I think that paying $50 or $100 for a new one is cheap insurance.

I'm still on the fence about the frame, though.

I had a bike with a dent about like yours. Read up on it and sounded like it wasn't a threat. I still didn't want to worry about it, so got another bike. If it bothers you then get a frame and transfer parts or just get another bike. If you read up on it in forums you'll see that kind of dent is not a threat. Its your choice and you have to live with that. If you do keep the bike, sounds like a new set of forks in is order.

Looking at the photo, it seems that this bike takes one fork (singular) like any other bike, or did you mean to imply a set as in a rigid fork and a suspension fork.

Steel frame? Personally, I wouldn't think twice about that dent.

And the fork can be saved. My father fixed one that was bent the same way years ago...And it lasted quite a few years after that. (The fork never did break, or even bend, but I can't recall what became of the bike itself).

It's all about finding someone with a blow-torch and little fear of lawsuits (i.e., not a LBS)

I know a guy who did something very similar to the fork on a Dawes Galaxy by getting a stick caught in the spokes and mudguard stays. He took it to a local framebuilder who bent it back again and re-aligned it. It IS repairable, the issue will be finding a framebuilder who's willing to do it.

Get a new fork, nothing will happen to that frame ever if you are worrying about a sudden explosion of the frame while riding, that is not going to happen unless somebody pranks you and put 1 dynamite stick inside of the frame.

Nobody can tell online if the fork is repairable for sure, and certainly not whether it's worth what a framebuilder might charge, but I'm fairly confident you are ill-advised to try, given the state of the fork crown. A chrome 700c replacement fork will probably cost about the same as alignment by a framebuilder. Both would require a headset overhaul, but the original would also require some touchup or a repaint, as the paint will peel when the fork is straightened.

As for the downtube dent, i would ride that. If it were me, I would take a look at the rear chain stays and look at the factory crimping that is done there for tire and chain clearence and then compare that roughly to the dent on the downtube. I bet you will see that the factory crimping on the chainstays is more than the little dent on the downtube.

I'm no expert but that is how i would rationalize it.

As for the fork, I might try to find someone who could straighten it but if not, I would look for a complementary color fork and replace.

Just one fork. I miss spoke

Given the severity of the bend on the fork, you aren't looking at a "dent" in the downtube but a buckling of the tube itself. Nothing 'hit' the tube to dent it but, rather, the tube tried to fold upon impact and is well on its way to failure. Looking at your first picture, the top tube looks like it might have some curve to it which the Volpe didn't come with. Forks are beefy...beefier than the frame... and if you can manage to bend them like you have, you've likely damaged the frame.

As for the thought that this is in a low stress area, this picture borrowed from here



would say otherwise. The area where you buckled the frame is in the pink zone of the downtube and is one of the more highly stressed areas of a bicycle frame. Don't try to straighten the tube, drill out a hole and punch out the dent, use a blow torch, think of it like factory crimping of a low stress area nor any of the other suggestions offered here. The frame is broken. It's not safe to ride and it is now scrap. Treat it as such.

This is a nice theory, except that it disregards all the physical evidence. The shape of the dent shows that it's a dent, and not a buckle. Moreover it's precise alignment with the fender brace, stretches credulity as a coincidence. What almost certainly happened is the fork pushed back pushing the wheel into the downtube with the fender brace trapped between them.

In any case, when downtubes buckle from front impacts it's almost always at the bottom directly behind the headtube. The reuslting buckles have a characteristic appearance (clearly a buckle) which this frame doesn't.

As far as safety goes, without any repair at all this frame has a decent chance of outlasting it's owner, and if and when it fails will give generous notice.

considering the price of comparable new frames of similar quality, i wouldn't give a second thought of trying to save that one.

If you ask a bike shop operator "is this frame still safe despite the damage" I can't imagine him ever saying "yes" - at least not here in the litigation-crazed U.S.

Don't disagree, especially with the last part.

Look at it this way. I dealer has nothing to gain by saying yes, and lots to lose if he turn's out to be wrong. Not only because of the risk of litigation if he's wrong, but also because this started out as a JRA. OTOH, saying it's unsafe might generate business, and will make him immune to suit.

It's the OPs bike, and his decision whether to ride it or not.

That's a hell of a fender brace! Look at the buckling of the downtube again. It is very deep (roughly 10% of the tube diameter). The tire would have mitigated damage from something as light as a fender bracket.

The buckle doesn't have to be right behind the head tube and the fender bracket could have been enough of a nudge to make the top tube buckle there rather than further up.

As you said above "That's a nice theory" but look at the evidence. You have a round down tube that isn't round anymore at a high stress point in any bicycle frame. The bike has been in a severe crash that damaged the forks...a very tough, strong part of any bike. I'll pose this question: Would you buy this frame and ride it? If not, why not? You said that a repair would outlast the owner and when it fails it would give generous warning.

I, personally, don't believe it would outlast the owner nor that failure would be slow.

The fender brace didn't have to be strong, it was the meat in a sandwich. It was trapped when the tire was driven into the tube. If this bike didn't have fenders, he would have ended up with a broader shallower dent, or maybe no dent at all. However there wasn't enough force to bend the entire tube upward or change the geometry of the frame (as appears in the photo). The OP can confirm that with a straightedge, or by checking the front wheel position with a new fork.

Obviously none of us were there, so anything we say is opinion. It's also opinion as far as predicting the outcome if the OP chooses to ride the bike. My opinion is based on what I see in the photo, and 45+ years working on bikes.

Look more closely at the last picture. The bend in the tube is v-shaped and very deep as well as spanning nearly the entire width of the tube. No fender brace I've ever seen is v-shaped like that dent.

Additionally, a tube gets its strength from the round nature of the tube. Make a part of it 'not round' and the strength decreases dramatically. This frame now has a 'not round' tube at a critical stress point. It may not fail for days, months or years. But it also may fail at any point. Failure of the frame at that point is going help the rider realize the value of a good dentist...if not a good plastic surgeon or neurosurgeon. Don't ride it Spld cyclist. It's busted.

What size frame is it? I have a Volpe,63cm I believe and will consider unloading it.