Bent frame in headtube area. Still usable?
 

Hello all,

I'd like to ask you guys what you think about this frame. The top and bottom tubes are slightly bent. Could it be from heavy riding in terrain with rigid fork ? Or is it deffinitely from a crash ?

I bought this frame for €30, and would like to build a touring bike on it. Nice steel frames are quite rare in my area, most of them just supermarket junk bikes. If it was easier to get a nice steel frame, I wouldn't even consider keeping it and would directly ship it back to the seller.

I weight 150lbs and would like to use it for asphalt or dirt road touring, no rough terrain, if that makes any difference. I'd like to put a rigid fork on the front.

What do you think?

http://bikeforums.net/attachment.php...hmentid=301707 http://bikeforums.net/attachment.php...hmentid=301708 http://bikeforums.net/attachment.php...hmentid=301709 http://bikeforums.net/attachment.php...hmentid=301710

A common cause of deformation around the headtube and connected tubes is a frontal collision, eg riding into a car or tree. Look under the blue tape for any surface ripples.
If the fork is weaker than the frame, the fork will bend back. If the fork is stronger, the frame will cave in.
I wouldn't like to ride a frame that suffered major collision.
I rode my 1970s falcon sports bike into the back of a car and wrote off the fork but the frame was OK.

So I guess this has been the second case i.e. stronger fork than frame :(

Anyway, do you think it's safe to ride it ? I don't see any cracks (and steel doesn't crack easily), just slight bend and a small bulge on the bottom side of each tube. If it wasn't for the cracked paint on top side of the tubes which attracted my attention to take a closer look, I wouldn't have noticed it.

The frame may not fail (no guarantee) but the geometry will be different. The head tube angle is greater and your wheelbase shorter, which will result in twitchier handling. You will have less room between your toes and the front wheel as well.

I just jotted a brief note before but now that I've re-read the post I have a few more comments. I agree this is a poor frame with which to start for a touring bike. It is indeed possible that the frame is not aligned properly any more. The other possibility is that the head tube has been distorted such that the headset will not fit in with a solid press fit.

Nothing but a collision would produce that bending. If the seller did not note that the frame was in a collision or include an "as is" disclaimer you should not only get a complete refund but, depending on the description and any rules of the venue on which it was advertised, you could be due shipping in both directions. At minimum you need to have a refund of the purchase price and shipping to you.

I would also ask why you are building from scratch, which in most instances will cost considerably more than buying a complete bike, and more importantly requires a very large amount of time and research into which parts are compatible with the frame, your usage and each other. I know, though that things could be radically different where you are as far as availability of bikes.

I'm in the "it was crashed" camp. As cny-bikeman noted the increase in headtube angle will quicken the steering and reduce toe clearance. Neither of these are desirable on a touring bike. If the lateral alignment is also off, the bike will not ride a straight line without continuous correction and that is REALLY undesirable with any bike, not just a tourer.

See if you can get your €30 back and keep looking.

Steel does crack easily. Every steel part and frame failure I've ever experienced has been a crack failing suddenly and catastrophically.

As for the lack of cracks, look more closely. The first picture shows cracks in the paint along the weld. The last picture shows them even better along with corrosion under the 'band-aid' of blue tape that was applied to hide the corrosion and cracks. Picture #6 shows a clear crack in the paint following the weld that goes at least half way around the downtube. Any crack in the paint should make you suspicious about the integrity of the frame. Cracks that follow welds should make you doubly so. Evidence of corrosion around a crack should make you triply suspicious. Sorry but this frame is toast. Ride it at your own peril.

OP; From what I can see in the pictures and given the lack of information. I would guess that the frame is not particularly special. I see bits of rusting, several spots when the TIG welding is not very good, etc. Hard to see it worth your while to start the project with a marginal, unknown quality, already damaged frame???

Would recommend just moving on. You can get a new alloy frame with chromo fork from Nashbar for $135USD in either touring, road, cross, MTB, styles. Other sources also such as Bikesdirect for complete bikes...

Ride it indoors, on the trainer, rather than on the road.

definately not, a broken frame on a tour could land you in the ditch. (or morgue)

Pony up the funds for a Thorn , shipped in from England, from SJS. [they ship world wide]

You want something reliable, for touring ..

OP; BTW, when you have made the final and correct decision, with our help and your money [;), be sure to take a hacksaw and cut the frame into at least two parts and put it in the recycling bin. Same for the fork. That way some idiot won't pull it out of the trash and end up getting hurt on it!

/K

I'd vote for sending it back. That frame is damaged and likely to be dangerous, especially with those cracks in the paint along the weld.

I expect they, (ebay seller?) lied about the condition, it was in..

You, may be, right.

I would honestly take the train to Graz for the weekend and pick up a nice used Puch and the local marketplace.

They should be quite cheap (less than €100), you could take the bike on the train and you'd get a weekend holiday in.

The train should be between 2-4h depending on speed.

Even better, just ride the bike back from Graz :D

Vienna is not far upstream..

yeah, bratislava near the epicenter of solid classic touring bikes (Austrian/German/Swiss). i'm not so sure about the italians ... style, sure ... but function ... hmmmm

you have a huge amount of options, no need to run a bent frame.

IMO you're definitely looking at the results of a front end collision. That's the only way to produce forces which push the fork back vs the frame. Bouncing, jumping, overloading or all manor of non-front end impacts, push the fork up and forward, so the bend would be in the opposite direction.

To understand the direction of bend, consider that the wheel can only transmit forces radially (through the axle). So draw a line from the crown through the axle and out to the rim. Impacts above where this line meets the rim push the fork back, impacts below push it up.

As to whether it's safe to ride, I won't asure you safety (nobody can) but will say that I'd have no qualms about riding it myself. How long it;ll last can be anywhere form days and weeks to forever, and depends on the amount of upset (rippled buckling) under the tubes, and the properties of the steel. A more ductile low end material will hold up pretty well, higher alloys worse.

In my years in the bike industires, I've seen hundreds of frames bent like this and ridden for years, including a handful that eventually failed (including my old Robin Hood 3-speed at 20,000miles. But I've never known (either 1st, 2nd or 3rd hand) of anyone being injured if/when these failed.

Also, contrary to some of the posts, EVERY frame that failed subsequent to a front end collision that I've seen or heard of, including one that I watch fail while a friend was riding, showed visible cracks under at the buckles under the tubes, long before it failed.

psst? OP is in Slovakia....

+1. I wouldn't go down a mountain road, loaded, at 80kph on that frame, or race it, but I'd say it doesn't look dangerous for casual riding.

if you are willing to monitor the frame for cracks it should be safe to ride. As stated by FBinNY above, cracks don't fail catastrophically in the sense that they are invisible one moment and broken through the next. It's just that people don't look. I'm guessing the likelihood of that cracking is somewhat less because there don't seem to be any creases, although the area around the weld is now more likely to crack even though it's not very near the bend.

Having said that, I don't ride bikes that I don't have complete confidence in. And touring is a good way to break a frame if there is any bike activity that will break a frame

well, the WORSE case is extreme mountain biking, of the big jump variety. I was watching a national compettion of this (one of my son's former HS buddies was in it) and saw a brand new factory team full suspension downhill frame literally snap in two right behind the headtube on a landing that was just a bit less than perfect.

Bike has been involved in a frontal collision. Picture 6 shows what appears to be several cracks. Use a small fine file to remove the paint to confirm this. The weld joint is also of very poor quality. If you see one or more cracks, then you must take the time to inspect for crack propagation every 500 miles. I would definitely not attempt to ride off-road or jumping the curb with this bike. Long distance touring is also not recommended.

I'd definitely return the frame and wait for a better deal.

I've had several bikes fail "catastrophically", depending on your definition. One was a Teledyne Titan (titanium) which failed in the middle of the down tube, the other was a Witcomb which failed at the intersection of the head and down tube.

The Titan was the first titanium frame sold and had several faults in design. No. 1 was that the alloy wasn't, but IIRC was nearly pure titanium unsuitable for use in cycling. No. 2 is that it used large diameter tubes (see aluminum), but had a crimped section so that one could use clamp on shifters. This was in an era before shifters were mounted on the handlebars. There was literally a right angle bend which created a large stress riserl The Witcomb was poorly brazed and there was actually rust in the joint. IIRC the lug actually broke. Rode the bike 20 miles home, slowly.

Of course, any failure creates a risk, even in casual riding. But a breakage will probably not cause a completely uncontrollable crash, merely a swerve into oncoming traffic :-).

Thank you for opinions.

and at the other extreme, circa 1978, I hit a steel cable at twilight coming down a fire road on Mt Tamalpais on my trusty steed...

http://pierce.smugmug.com/By-Date/20...MG_5140-X2.jpg

headset didn't get knocked out of alignment one bit, steering tube didn't bind, so I just kept riding it. and riding it. touring, centuries, double centuries, commuting. fun. thats a circa 1975 (might be a 74?) Motobecane Grand Record, reynolds 531 double butted throughout.

BTW it's a circa 1994 (s.no. starts with 94) Marin with Tange CrMo tubing. The sticker doesn't say 'Double butted' and the rear dropouts are rather low-end and from the catalogue I'm guessing it could be Bobcat Trail.