# Is my (repaired) bent steel frame and fork safe?



## AllysonG (Feb 5, 2011)

Greetings,
I would really appreciate any input on this issue since I am not a very experienced cyclist. I crashed my daily commuter, a 1982 steel frame road bike, several months ago. Crash involved riding over 2 curbs at pretty decent speed, followed pretty rapidly by decent onto the pavement. I broke four front teeth and lost a bunch of skin from my face/lip. My bike ended up with a bent fork such that the front tire contacted the down tube, a dimple in the top tube near the head tube and a very bent front wheel (dented and twisted). 

I recently gathered the courage to revisit the idea of bicycle commuting, and took my bike into a local shop. I was told that the frame/fork could be bent back into shape, but there would be risk that due to metal fatigue, it could break at some point, which could induce another close encounter with the ground. I figured it was written off, so took it to the local community bike workshop to donate for parts.

At community bike center, I was told by very kind and seemingly knowledgeable volunteer that my bike was salvageable. We used a frame bending device (?) and a vice to manually bend the fork back into a more fork-like shape. I was told to replace the wheel.

I realize that there is risk in everything, and cycling is no exception. That said, I wish to minimize risk as much as possible in light of recent experience (and the resultant medical bills!). How scared should I be about riding this bike vs. getting a new/used one? For what it's worth, I plan to change over to straight handle bars if I do get back on this bike. 

Thanks in advance.
- Allyson


----------



## bigbill (Feb 15, 2005)

I would scrap the frame and move your parts over to another. Find a used steel frame and recycle the old one. If the cycling community is as tight and helpful and your post makes it out to be, you should be able to put the word out that you're looking for a frame in a certain size. Lots of time people have frames stashed away that they don't know what to do with and you could get lucky. I have four frames just sitting around waiting for a future build. 

If you wanted to go new, Surly, Pake, and Soma are nice choices that don't involve a huge investment. Any one of them could be used with flat bars.


----------



## rx-79g (Sep 14, 2010)

If it didn't crack bending it back, and you're not a particularly heavy person, I don't think you're ever going to have a problem. Steel is pretty durable stuff, even if it has been bent about.

Even if it does go bad, I doubt it will be a spectacular failure. Just some cracking rather than an all out failure.


----------



## Kuma601 (Jan 22, 2004)

Sorry to hear. Hope your injuries have healed well. 

Would you happen to have pictures of the frame damage? My mental picture doesn't paint it pretty though as rx-79g mentioned, the bike may still be ok. IMO, taking a conservative approach by buying a new frame might give you some additional peace of mind. I say treat yourself.


----------



## kiwisimon (Oct 30, 2002)

after the beating you took and you got back on, you deserve a new bike. (Frameset at least) The fork won't be completely balanced and there is a chance the head tube is out of alignment. It rarely happens in the political forum but I agree with the big sailor called Bill. And welcome to RBR.


----------



## FatTireFred (Jan 31, 2005)

I'd be hesitant to ride a repaired fork


----------



## cpcritter (Sep 24, 2008)

Given the great price of some very good frames and forks, either new or used, why not get a replacement? I would never take the chance to bend it back. Never.

BTW-I have a complete bike, albite a cheapo, it's yours if you pick it up in SW Ohio.


----------



## TWB8s (Sep 18, 2003)

There's a lot of variables in the damage to your bike. I'll accept that the mechanic at the LBS recognized a repairable frame and fork. It sounds as though he used the same frame tools I've used so nothing sounds out of the ordinary. Without knowing the make of your frame, it's difficult to know how well made it was. A few frames are under built, some over built, most are in the area between. It is well made enough to endure you crashing it and the mechanic realigning. Unless you feel overwhelmed and want to replace it, I don't feel you need to replace it. I base that feeling having worked as an LBS mechanic, manager and professional mechanic. If I could see the frame in person I could state as a matter of fact whether the frame was a danger or if it would last you the rest of your life. the rest of your life? Yes. It's a steel frame. If a tube or even a lug fractures it can be replaced. If it is a high quality frame it would be worthy of such a repair and the cost to do so wouldn't be out of line. As for your safety, as with your car or any piece of equipment, you should pre-ride check it periodically. If something looks suspicious, take it to the LBS and have them look at it. I doubt they implied a warranty for the frame repair, I wouldn't. But if a crack does appear, it's a steel bike, it won't fail abruptly as other materials do.

So, Ride it. Watch it and ride it some more.


----------



## velodog (Sep 26, 2007)

Ride it.
If you're nervous about it find a frame builder near you and see if he'll take a look at it.
But, like FTF says, I'd be concerned about the fork.


----------



## Kerry Irons (Feb 25, 2002)

*Agree*



rx-79g said:


> If it didn't crack bending it back, and you're not a particularly heavy person, I don't think you're ever going to have a problem. Steel is pretty durable stuff, even if it has been bent about.
> 
> Even if it does go bad, I doubt it will be a spectacular failure. Just some cracking rather than an all out failure.


^^^ this


----------



## Fredrico (Jun 15, 2002)

*Ride it.*

Another vote to ride it. If you see paint chipping off the top tube around the dimple, or up on the fork crown, that might be signs of failure. But it'll get loose before it gives way. :shocked: There will be warning.

I crashed my lugged steel bike 25 years ago, dimpling the down tube and putting a ripple on the top tube. The fork was bent back about 3 inches at the dropouts. The frame builder put it in a jig and bent everything back, re-aligning the head tube and fork blades, like your guy did. I've been riding it ever since. About 60,000 miles later, still no cracks or fissures, and it rides fine. CRMO steel used in bike frames is really tough. Takes a lot of bending back and forth to break it.


----------



## AllysonG (Feb 5, 2011)

*Thanks!*

Thank you very much for all of the replies. 
The bike is a Bridgestone Triathlon Al. Old, but well taken care of and was in good working order and a smooth, fast ride. Replaced the wheel and gave it a ride this morning. Handled pretty poorly, probably on account of the fork. Also, I need to mess with the front brake a little as it was not functioning well. It is some relief to hear that if the fork/frame fails, it is unlikely to be catastrophic, so I will keep a close eye on the areas of concern. I think I will end up replacing the bike at some time when I have finished paying off my thousands of dollars in medical/dental bills! I so want to continue riding, but this bike
Thanks again for all of the input and advice.


----------



## rx-79g (Sep 14, 2010)

AllysonG said:


> Thank you very much for all of the replies.
> The bike is a Bridgestone Triathlon Al. Old, but well taken care of and was in good working order and a smooth, fast ride. Replaced the wheel and gave it a ride this morning. Handled pretty poorly, probably on account of the fork. Also, I need to mess with the front brake a little as it was not functioning well. It is some relief to hear that if the fork/frame fails, it is unlikely to be catastrophic, so I will keep a close eye on the areas of concern. I think I will end up replacing the bike at some time when I have finished paying off my thousands of dollars in medical/dental bills! I so want to continue riding, but this bike
> Thanks again for all of the input and advice.


What's the "Al" mean? I thought this was a steel frame and fork, and all comments regarding repair and rideability were based on that. 

If the handling sucks, stop riding it. What feels crummy at low speeds could be quite dangerous in other regimes.


----------



## bikerjulio (Jan 19, 2010)

The damage discussed here is either the cause of, or the result of a crash - there seems to be some uncertainty about the matter. Either way I would err on the side of caution in your case.

http://bbs.homeshopmachinist.net/showthread.php?t=46317


----------



## Fredrico (Jun 15, 2002)

*Hmmm.....*



AllysonG said:


> Thank you very much for all of the replies.
> The bike is a Bridgestone Triathlon Al. Old, but well taken care of and was in good working order and a smooth, fast ride. Replaced the wheel and gave it a ride this morning. Handled pretty poorly, probably on account of the fork. Also, I need to mess with the front brake a little as it was not functioning well. It is some relief to hear that if the fork/frame fails, it is unlikely to be catastrophic, so I will keep a close eye on the areas of concern. I think I will end up replacing the bike at some time when I have finished paying off my thousands of dollars in medical/dental bills! I so want to continue riding, but this bike
> Thanks again for all of the input and advice.


:idea: If the bike now handles poorly compared to before, is there a frame builder nearby to put it in a jig and check alignment? I guess you can see if the head and seat tubes aren't parallel.

A frame builder could check the fork alignment, too. If the brake pads aren't centered anymore, the brake caliper could be bent out of alignment, or the fork is misaligned side to side, which would explain poor handling.

If the fork couldn't get bent back to spec, the LBS can still get a steel replacement with one inch threaded steerer tube and lugged fork crown. The ones I've seen are also chromed. They can be had for around $100. A replacement carbon fork might work too, for the same money. Rakes and offsets are pretty standard. 

Forks often split at the steerer tube/fork crown join, where you can't see it. You don't want that to be the reason the bike handles poorly. That's where there's major stress and where forks finally give up, like a loose tooth. :shocked:


----------



## Fredrico (Jun 15, 2002)

*Had the same thought.*



rx-79g said:


> What's the "Al" mean? I thought this was a steel frame and fork, and all comments regarding repair and rideability were based on that.
> 
> If the handling sucks, stop riding it. What feels crummy at low speeds could be quite dangerous in other regimes.


I googled a Bridgestone Triathlon AL for sale on craig's list that is a lugged steel frame with a lugged fork crown, so I think we're still on track.


----------



## Fredrico (Jun 15, 2002)

bikerjulio said:


> The damage discussed here is either the cause of, or the result of a crash - there seems to be some uncertainty about the matter. Either way I would err on the side of caution in your case.
> 
> http://bbs.homeshopmachinist.net/showthread.php?t=46317


Interesting link! Sure looks like faulty brazing to me! The tubes just pulled out of the lugs with no visible bending. Silver brazing (as it was described) on short point lugs is pretty chancy. Silver is used so as not to heat up the metal so much that it becomes brittle and loses its "modulus of elasticity." Silver melts at lower temperature than copper, the usual brazing compound. This Bridgestone bike we're talking about is surely copper brazed by machine, so I'd doubt the tubes would pull out of the lugs in a catastrophic failure like the one pictured. More typically, the tube would crack around the lug join.


----------



## rx-79g (Sep 14, 2010)

Fredrico said:


> Interesting link! Sure looks like faulty brazing to me! The tubes just pulled out of the lugs with no visible bending. Silver brazing (as it was described) on short point lugs is pretty chancy. Silver is used so as not to heat up the metal so much that it becomes brittle and loses its "modulus of elasticity." Silver melts at lower temperature than copper, the usual brazing compound. This Bridgestone bike we're talking about is surely copper brazed by machine, so I'd doubt the tubes would pull out of the lugs in a catastrophic failure like the one pictured. More typically, the tube would crack around the lug join.


Silver brazing is an industry standard - all lugged Treks were made this way. It is not weak. The top joint shows evidence of poor wetting, possibly from underheating the base metal.

Those are, however, some ridiculously tiny lugs for brass or silver on a tall frame.


Allyson,
It's one thing to have concerns about the metalurgical strength of a bent and re-bent bicycle. But it doesn't sound like your frame or fork were correctly bent back into shape. Getting a frame builder to align it will likely cost close to what a used frame would cost, and you'll still have a question about the steel's strength. I think it is time to move on.


----------



## Fredrico (Jun 15, 2002)

*On silver brazing..*



rx-79g said:


> Silver brazing is an industry standard - all lugged Treks were made this way. It is not weak. The top joint shows evidence of poor wetting, possibly from underheating the base metal.


Scanning the responses on the link, one thought the joint had been prepped and wetted properly. Another said, without naming the builder, that his reputation was unassailable. I remember reading a book back in the 80s interviewing builders. Most of them stayed away from silver, saying it was, in effect, too soft. They'd had problems with the lugs coming apart, just like in the pictures. Copper never did that, unless it was really badly brazed, not enough heat or enough material to fill the joint. Sure enough:

_I ran into several issues with silver soldered socket joints in the Navy. Even properly made, the joints would sometimes fail after a period of use. This type of joint was prohibited for use in submarine seawater systems for the simple reason that they could fail unexpectedly and catastophically._​
So I don't think a tube pulling out of a lug would be worrisome on a copper brazed frame, which Allyson's surely is. Just sayin'.


----------



## rx-79g (Sep 14, 2010)

Fredrico said:


> Scanning the responses on the link, one thought the joint had been prepped and wetted properly. Another said, without naming the builder, that his reputation was unassailable. I remember reading a book back in the 80s interviewing builders. Most of them stayed away from silver, saying it was, in effect, too soft. They'd had problems with the lugs coming apart, just like in the pictures. Copper never did that, unless it was really badly brazed, not enough heat or enough compound to fill the joint. Sure enough:
> 
> _I ran into several issues with silver soldered socket joints in the Navy. Even properly made, the joints would sometimes fail after a period of use. This type of joint was prohibited for use in submarine seawater systems for the simple reason that they could fail unexpectedly and catastophically._​
> So I don't think a tube pulling out of a lug would be worrisome on a copper brazed frame, which Allyson's surely is. Just sayin'.


You're picking and choosing what to quote, there. Another poster mentioned using silver on modern power plants, and yet another pointed out the wetting problem.

I don't know about the '80s (except that Trek used silver since the '70s), but I'll guarantee you that all the big name builders of lugged bikes are not using brass. Serotta, Waterford, David Kirk, Richard, Sachs, Vanilla, etc. Brass requires too much heat for modern thin guage tubing.

Check out Velocipe Salon sometime if you are interested in keeping up with such things.


----------



## Fredrico (Jun 15, 2002)

*Ok, sure.*



rx-79g said:


> You're picking and choosing what to quote, there. Another poster mentioned using silver on modern power plants, and yet another pointed out the wetting problem.
> 
> I don't know about the '80s (except that Trek used silver since the '70s), but I'll guarantee you that all the big name builders of lugged bikes are not using brass. Serotta, Waterford, David Kirk, Richard, Sachs, Vanilla, etc. Brass requires too much heat for modern thin guage tubing.
> 
> Check out Velocipe Salon sometime if you are interested in keeping up with such things.


Silver is now preferable for hand brazing paper thin tubing, as it requires less heating of the tubes.

Nonetheless, addressing Allyson's problem, her frame was made back in the 80s, probably by machine, using brass braze. As another respondent (Portland, OR) claimed:

_I count among my friends one of America's elite framebuilders, Mark DiNucci. Here's his take on it.

"I know the problem quite well. the problem is caused by incorrect heat treatment to the lug for the use of silver braze. the frame shown was silver brazed. it was not prepped correctly after braze and or paint. this is why it is rusted. even though it is rusted it shows no overt signs of stress corrosion failure. *if the frame had been brazed with brass it would not have failed.* the lugs may have been cast by Hitachi. i still have a nice supply of these."

I was a bike mechanic for many years, and have dabbled in framebuilding myself, but this is a new one on me. I didn't know that the heat treat condition of the lug could affect the silver brazing bond. But Mark is a true expert, so I'll take his word for it._​


----------



## rx-79g (Sep 14, 2010)

Fredrico said:


> Silver is now preferable for hand brazing paper thin tubing, as it requires less heating of the tubes.
> 
> Nonetheless, addressing Allyson's problem, her frame was made back in the 80s, probably by machine, using brass braze. As another respondent (Portland, OR) claimed:
> 
> ...


Yeah, Mr. Heat-treated lug guy (BS). Steel lugs stop being heat treated when they are torch heated above where they could have been heat treated to. If the metal is glowing, it's no longer heat treated. 

As far as Allyson and all other lugged bike owners go, filler failures on lugged bikes are rare and due to defects, not material failures. Silver or brass. The linked thread is interesting, but mainly in its rarity. All those thousands of 30 year old silver soldered Treks out there are testiment to the material.


----------



## Kuma601 (Jan 22, 2004)

A good shop with a frame alignment jig can probably do it. Anticipate the cost to be north of $175. 

In this instance, I'd say enjoy the new bike shopping.


----------



## Fredrico (Jun 15, 2002)

*Perfect.*



rx-79g said:


> ..As far as Allyson and all other lugged bike owners go, filler failures on lugged bikes are rare and due to defects, not material failures. Silver or brass. The linked thread is interesting, but mainly in its rarity...


 My response was intended to re-assure Allyson that tubes pulling out of lugs are the least of her worries. Perhaps alighting on silver braze failures after seeing the pictures in in bikerjulio's link, I got off track. But reading through the posts in the link, it appears silver runs thinner into the cracks and fissures of a joint, and, possibly because of "improper heat treating" beforehand (I'm speculating), doesn't fill in the voids as completely as brass, therefore fails more readily if closer tolerances aren't satisfied. :biggrin5: The Trek frame builders and their counterparts obviously overcame that problem, but the builder of this pictured frame apparently didn't. I've never seen a brass brazed join come apart like this, unless its heated with a blow torch.  

Anyway, both of us surely agree Allyson should be concerned with alignment, rather than tubes and lugs separating! And sure, when finances allow, replace the bike. :yesnod: :thumbsup:


----------



## rx-79g (Sep 14, 2010)

Fredrico said:


> My response was intended to re-assure Allyson that tubes pulling out of lugs are the least of her worries. Perhaps alighting on silver braze failures after seeing the pictures in in bikerjulio's link, I got off track. But reading through the posts in the link, it appears silver runs thinner into the cracks and fissures of a joint, and, possibly because of "improper heat treating" beforehand (I'm speculating), doesn't fill in the voids as completely as brass, therefore fails more readily if closer tolerances aren't satisfied. :biggrin5: The Trek frame builders and their counterparts obviously overcame that problem, but the builder of this pictured frame apparently didn't. I've never seen a brass brazed join come apart like this, unless its heated with a blow torch.
> 
> Anyway, both of us surely agree Allyson should be concerned with alignment, rather than tubes and lugs separating! And sure, when finances allow, replace the bike. :yesnod: :thumbsup:


I guess I didn't explain well enough. Lugs are cast steel. Steel is heat treated by raising the temperature of the steel until orange/red or higher, then quenching and tempering. Heat treatments of normal steels cannot survive being heated again to red hot, like what happens everytime you braze a frame together. That's why that guy's response was non-sensical.

Silver fills voids BETTER than brass. It has superior wetting characteristics and will migrate into finer spaces than brass. Brass does have a greater shear strength than silver, but doesn't explain the appearance of that failure with the uneven surface, because the diffusion bond to the steel is higher than silver's shear strength.


----------



## GirchyGirchy (Feb 12, 2004)

I had a bent fork repaired by a frame builder about five years ago. It wasn't bent as badly as yours but came back looking brand new. No problems since.


----------



## Doggity (Mar 10, 2006)

To the OP: you've got balls, getting back on the same bike after a crash like that! I'd say if it's handling poorly due to the fork not being quite the same, steel forks are pretty cheap...
replace it! Just make sure you get one with the same dimensions. Heh...you don't want to know what can happen if you replace it with a little bit shorter fork, and you're off roading.
I found out the hard way


----------

