[MENTION=381793]gugie[/MENTION] - I would have paid cash to come watch that! Nice work.

Nicely done [MENTION=381793]gugie[/MENTION]. I knew I sent it to the right place.

Brad

Based on the decal, the only thing guaranteed is the main triangle, but based on the amount of force it took to bend them (permanently), I'd say the rear triangle was a higher yield strength alloy than hi ten.

Yep. That a good vise, proper tools, and a steely attitude.

Yea of little faith...

edit: added permanently to be more concise

Not surprising that it was something better quality. A lot of bikes were built that way with 531 main triangle and something cheaper and heavier but still good for the fork and stays.

Hi tensile is surprisingly easy to bend. I picked up a Peugeot UE 8. I popped in a 126 mm rear alloy wheel and the stays opened like butter. I was surprised by how little resistance there was.

The modulus of elasticity for just about all steels is the same. If you were to build a frame from cheap steel pipe and one out of Reynolds 953, as long as it had the same wall thickness, they would ride the same. That is, as long as you didn't crank down on the steel pipe frame and permanently bend it. An easy analogy would be to make a spring out of both materials with the same shape and size. They would both bend the same under a small load, then bend back (elastic deformation). At a higher load/bend distance the cheap steel would bend permanently, while the 953 spring would continue to spring back.

So, bending that UE 8 stay easily might have to do with the diameter of the tube near the bottom bracket and large indentations for tires and chainrings. Or maybe you're saying it was easy to bend and stay bent?

No not easy to stay bent. I did not actually bend the stays. I just pushed them apart to insert the wheel. It was set at 120mm and the wheels are 126 mm. When I've done the same thing with a higher quality steel, it was much harder to just push the steel apart. I've had good luck by just pushing the stays apart rather than cold setting them. I know you're not supposed to do it this way but it has worked well for me repeatedly.

[MENTION=381793]gugie[/MENTION] Me too! Very nice job on the frame. Your tools for straightening a bent stay are much more advanced than mine.

In the past, I grabbed an old 70s schwinn frame (nothing special) that had a seriously bent seat stay out of the scrap pile. It was bent a good 15 degrees DIRECTLY above where the dropout ended (inside the stay.) I figured, "what the hell, I'll try to straighten it" good experience at least. So I duck taped (yes... you heard that correctly) a very strong crowbar to the outside (concave) side of the bend, insulating the frame paint with a few pieces of pipe that I had cut in half lengthwise. The whole apparatus looked like a bow and arrow (just the bow part) with the crowbar being the "string." Then I put the whole thing in a vise, again insulating the frame paint with some half rounds of pipe, or possibly wood, I forget. And cranked on it. It certainly worked, I went very slowly. But you seriously have to OVERBEND the stays to make them spring back to "straight."

Then, of course, I had no way of checking dropout alignment, so I just kept trying to mount a wheel and bent the dropouts with a crescent wrench.

It worked, the bike rode fine, although it was hard for me to tell because it was so large.

The moral of the story is, I would have love to have watched how it was supposed to be done. While my method worked, it certainly wasn't right.

Good work gugie! I cold set a Pinarello frame in almost identical condition using 2 x 4s and it straightened OK. I put a hub on though, thinking it would help to bend the stays together.

So you noticed I am not perfectly straight when we rode together a month ago? Was the big shim under my cleat the giveaway or the mangle shoulders under my jersey?

I haven't laid that straightedge on my bikes. But I am pretty sure thay are a lot straighter than I am!

Ben

[MENTION=302603]bikemig[/MENTION] and [MENTION=345109]corrado33[/MENTION] - the force required to execute a change is dependent on not only material properties but geometry of the assembly and parts. It is a little more complex than comparing different bikes and the force required to cause dimensional change. There is a big difference in the results between slowly applying force and using impact. In the latter case the change may be localized compared to the former where the chance can be distributed over a larger area. Bends vs dings.

[MENTION=302603]bikemig[/MENTION] and [MENTION=345109]corrado33[/MENTION] - the force required to execute a change is dependent on not only material properties but geometry of the assembly and parts. It is a little more complex than comparing different bikes and the force required to cause dimensional change. There is a big difference in the results between slowly applying force and using impact. In the latter case the change may be localized compared to the former where the chance can be distributed over a larger area. Bends vs dings.

I hope I didn't give the impression that I know what I'm talking about cuz I don't know nothing about the property of various steels. I just know what I work on and sometimes what I do works and sometimes it does not. And when it does not, I ask help from the pros.

lol

Are the UO(E)-8s built of high tensile steel? It sure isn't the same steel the Japanese used for so many of their lesser bikes. My UO-8 acquired a new alignment every time I laid it down. Not a big deal. It was easy to straighten. (I usually didn't bother. Doing chiropractic on an earthworm? What;s thew point?) When I worked at a Fuji dealer in the late 70s, those el cheapo S10-Ss were a lot harder to bend. So were all the other Fujis. I've always considered the Peugeots a small step better (maybe) than mild steel. Now my UO-8 was 1967. Maybe the steel improved later. What year was your UE-8? The stays opening like butter? Yeah. That's what I remember.

Ben

[MENTION=302603]bikemig[/MENTION] - That is the issue, isn't it. We don't know what we are working with, other than the difference in geometry that is visually tangible. The differences between steel's is so small that it is hard to know the difference unless there are certain operations or functions we are doing that exposes them and then only because we have done them before (experience).

I had the opportunity to "straighten" a fork that was in a front end accident. A number of people told me it was toast. What is often forgotten about steel forks is that they were not made with the bend to begin with. It was the frame or fork maker that bent the fork end to the desired geometry.

The risk in bending them back is about work hardening (changing the material properties) and the possible impact of undesirable deformation. If you can't see any damage, it is likely ok. You would not be able to tell the difference in the ride before the two bending events and after.
[MENTION=381793]gugie[/MENTION] - Great that you are having fun with such stuff! We are enjoying every thread that you share your experiences. The only thing better would be to do some of that stuff! I would love to build my own frame and maybe some day I will.

For those wondering how I did this, there's no magic.

Check all the joints for cracking. In this case the brazework looked top notch. Find where the worst bend is. In this case, you can easily see it from the pictures. Measure how far the offset is, using the string method (least accurate), a frame alignment gauge like I did (more accurate), or a framebuilders flat table (most accurate). I've checked the alignment gauge against a flat table, at most I'm 1-2mm off of perfect. The one thing I can't check is twist between the head and seat tube.

Next, clamp where you want the fulcrum to be. In this case it was obvious - there was a kink right at the brake bridge. So I clamped right above that and started with a small tug, check to see if it moved, and increase the force a bit at a time so you don't overshoot. After every step I check the dropout width, centering of the dropouts on the frame, and straightness of the stays. Rinse and repeat until the stays look good against a straightedge. Once everthing looks straight, focus on centering, then put the mojo to work on dropout parallelism.

Fancy way of saying just bend it till you like it. And, pics, so it did happen!

A couple bucks for a 2 x 4, and you proved that you don't need to spend a lot of money on tools.

Trust me, most framebuilders I know don't have an engineering degree. If they did, they'd be working as engineers and make a lot more money!

When it comes to bicycles, experience is a lot more important than book knowledge in this field. So much of it is "feel", whether it's truing a wheel, adjusting a derailleur, or bending a frame back into shape.

A simplistic way of thinking about steel is that it's like a cat with nine lives. Every time you bend it, you use one up. A real big bend, maybe two or three lives.

Compare that to aluminum, which has maybe two lives. Carbon fiber, one.

Oversimplified? Of course. But the takeaway is that bent steel frames, more times than not, are salvageable.

[MENTION=381793]gugie[/MENTION] I thought the way to check for twist between head and seat tube is the string test?

Well, if the head tube were pretty long, it might. You could wrap around the top of it, cross over and tension around the dropouts and measure, then slide it down to the bottom of the head tube and repeat. I'm guessing if you could actually measure a difference that you could look across the head tube to the seat tube and see it was out.

Some frame builders I know check everything against a frame table. I know some that don't believe in cold setting the main triangle. The amount of force it takes to cold set those big tubes is pretty large, the tools used include some very long solid steel rods. Here's one example:



More on this pic are https://ninelittletubes.wordpress.co...rtland-oregon/.

So, even if you could measure or see the two tubes misaligned, unless you've got some serious fixtures, there's not much you could do about it. Anything less than a full alignment table would risk damaging the frame

For what it's worth, the UBI class teaches one not to worry about main tube aligment. Proper jigging and brazing sequence/procedure will get you a "straight enough" frame. They have a large Marchetti table, but only use it for students to check their finished product. They stated that when they used it in the past, more students destroyed a perfectly rideable frame trying to dial in that last mm than it was worth.

^That is such a pretty frame.

[MENTION=381793]gugie[/MENTION] thanks for the lesson. I was not familiar with the whole procedure.

[MENTION=381793]gugie[/MENTION] strikes again

Nice save!

DD

Zeus frame - is it salvageable?

.....the only answer is undoubtedly and unquestionably YES!
I think, ........it has yet to pass the:
'Can I ride it blindfolded, with NO HANDS in a wicked crosswind?' test.


Since I was advised to build it anyway soonest, and Dr Zeus-ifiy the cyclemobile as things come up, I submit that a build (of Suntour or mixed stuff) is already underway.

I will update this thread with more detailed pics, when I begin cleaning/waxing/treating the frame/fork; will ask help dating the frame at that time. Guessing mid-70s.


I haven't seen many Zeus threads on this Forum.


There are impressions of a serial number on the BB, but thick paint obscures it, no sanding or scraping planned.


More in a few days.