cudak888 

The second machine came for a visit late tonight:

Data Point #2:

Frame: Said to be a Torpado, but no markings to correlate this.
Tubing: Assumed to be Columbus. SP? SL?
Wrinkling: Some below lower head lug, minor behind upper lug.
General damage category: Low-moderate

Crash history:
Rider caught front wheel with toe clip + shoe while maneuvering and endo'ed at low speed. Was used as a fixed conversion; might explain why the toe clip jammed the front wheel that violently - pedal might have been on a downstroke?

Headtube ended up bending to 75/76 degrees. Tube sat at around 72 degrees originally (small frame = slacker head geometry).

Before and after Park HTS-1:
The worst wrinkled areas were situated below each headlug, immidiately behind the lug spear. Lower lug fared the worst with a significant wrinkle. Top tube much more moderate. No headtube damage or warping.

I was quite surprised to see that the worst of the wrinkling - below the lower headlug - nearly disappeared after straightening the headtube. All that remains is a paint split (visible in the photo). The top tube remains slightly warped (barely visible, though one can feel it), though no serious creases remain afterwards.

Photos:

BEFORE:




AFTER:




Conclusion:
A smashing (pun not intended) success. The results are very good, and the tool worked as intended.

-Kurt

noglider 

I would ride that Torpado now.

I really like your writeups as well as your work.

cudak888 

Thank you, Tom.

I wish I fit that frame too...

-Kurt

noglider 

Got any plans for it? I'd fit it.

cudak888 

Send me a PM.

-Kurt

randyjawa 

As soon as I run across a bent frame set, I will have a go at straightening it and take good, step by step, pictures.

When I repaired the bent PX10, I used the tool being discussed, however; I also tried to focus pressures where the bends occurred. I am not sure that I can explain how I did this without pictures, but it amounted to putting pressure on the top tube, attempting to push it in the direction I wanted it to go.

As I applied pressure, I watched very closely for any signs of distortion. Remember, I have been working with metal for a long time. Also, it took me several tries to get it to move even a little.

Don't get is a hurry. Repeat, measure and repeat, until you get the results you seek or screw it up so bad that you will take up TV instead of bike riding.

miamijim

I think the Torpado damage is at the extreme end of what the tool can safely straightene. Anything more than that would have serious rippling and possibly kinking of the tubes.

Glennfordx4

Sorry Kurt I ment to put a at the end, I wouldn't think you would send that to a total stranger on the internet. I am just sitting on the Schwinn for now as I don't have the time or drive to do something with it ,I just wish someone closer to me would trade me something and do something with it it's in my way.

That is one tool I would like to own,I just thought of a guy that might have one close by I will go see him soon.

Jonatan F

How do you know when the tube is straight? A good ruler, messurement or just your eyes?

miamijim

That's a very good question. In my 12 years of shop experience I probably straightened 100 frames with a similar tool. As oddly as it sounds you can 'see it'. It's a combination of stepping back and eyeing it up, using tactile feel on the tubes, visibly looking for signs of 'reverse rippling' and if you have some type of angle gauge you can compare head and seat tube angles.

A more challenging aspect of this repair is removing 'twist' from the main triangle. Unless the impact was dead head on odds are the head tube is no longer in the same plane as the seat tube. Eyeing that up can be done but in my opinion it's very difficult to get a head tube in the same plane as the seat tube.

cudak888 

I didn't weigh the top tube in either case shown here. However, I did make it a point to watch the tubes set and settle, and found that the top tube curves in the center when under tension. Not by much, but enough that one can see it. It deflects back into position once one eases pressure. I found that I had to slightly overcrank the tool in both cases to counteract the memory of the steel.

That said, the headtube isn't the only thing to move when resetting it. Both the top tube and downtube work their way down a couple of degrees, offsetting the kinks behind the lugs.

Agreed. Nevertheless, I'm rather surprised it did such a good job on the Torpado in the first place. I'm quite inclined to purchase the tool at this point, but I would like to give a few more frames a try, including Schwinn EF

As Jim pointed out - by eye. With all due respect to Randy, I don't think there is much science behind this tool - it does what it does. Both of these frames took under 2 minutes to straighten, using only the tool and eyeballing the angles.

Frankly, I doubt any other frame tools could have improved the results of Test #1 or Test #2. As one cranks the headtube, the top and down tubes naturally return to their original positions.

I don't mess around with main-triangle twist without a frame table and a dial indicator. I had to repair a '75 Raleigh Twenty that way. Extremely hard to eyeball it, but the dial indicator told all.

-Kurt

rhm

I would be interested in hearing anecdotal ride reports, comparing how a bike rode before it was damaged versus how it rode after this repair.

I have one such anecdote. In 1980 I worked at a shop where we had this tool, and used it to straighten a Miyata tha had collided with a car. It was a classic example of the kind of damage this tool can fix. The owner really loved that bike, and was glad to be able to ride it again; and the repaired bike looked as good as new. Well, almost; there were subtle ripples in the paint right where you'd expect them. Anyway, the owner was thrilled to get it back in ridable condition; but after riding it, he didn't love it any more. It didn't feel the same.

Of course, one can always ask... was that real, or all in his head? Does it matter? (What's in my head is real; everything else is imaginary).

elguicho 

There is a Paramount frame on Ebay that could use this treatment. It is almost my size... mmmmm

cudak888 

I haven't seen any bent Paramounts on eBay? What auction is it?

-Kurt

delicious

Very interesting thread and great write-ups as usual, Kurt.

miamijim

I'd say it was combination of structural and mental but probably mostly mental. What I can say, and I'm sure everyone else will agree is that a straightened frame will never be as strong.

Zaphod Beeblebrox 

https://cgi.ebay.com/ws/eBayISAPI.dll...E:B:SS:US:1123

I was watching it earlier this week until I realized "What the hell am I gonna do with a Paramount with crash damage"

cudak888 

Speaking of something that isn't worth the price of admission. That's already $90+ for a wrecked frame w/shipping.

-Kurt

Zaphod Beeblebrox 

My feelings exactly

it was $0.99 when i started watching and around 20 bux when I took it off my watch list. I really didn't even expect to see one bid.

elguicho 

I was watching it mostly because I will need a badge for my beat up Paramount.

cudak888 

Here is frame #3 . Like the Windsor, a complete write off, but I nevertheless wished to experience what would happen with Reynolds 753 first-hand.

Data Point #3 :

Frame: 1987 (?) Raleigh Team Professional, Jan Legrand SDBU build
Tubing: Reynolds 753R
Wrinkling: Major crumpling on downtube, very slight downwards bend to top tube. Headtube warped under top head lug.
General damage category: Extreme+

Crash history:
Little known about crash, except that it was a high-speed impact.

Before and after Park HTS-1:
This frame was obviously a failed cause before I ever put it in the HTS-1. Downtube had collapsed behind shifter levers, with noticeable creases. The top tube had only the slightest of a downward curve; the headtube took the rest of the force that would have otherwise taken out the top tube - note the warp under the upper head lug.

Nevertheless, I proceeded to pull the downtube straight. Though the previous two frames had experienced reverse bowing of the top tube under pressure (and sprung back after the tool was loosened), the 753 frame bowed significantly. So much so that the top tube remained noticeably bowed after the tool was removed.

The downtube never did straighten out entirely - the top and bottom halves are about two degrees off. The sharp creases began to crack open in the process; the tool was de-tensioned after snapping sounds were heard from this area. Two visible gaps formed from the crease locations.

Photos:

BEFORE:




UNDER TENSION:


AFTER:








Conclusion:
Failure all around. I knew that beforehand, but I wasn't expecting the tool to add additional damage to the top tube.

Before I dismiss this tool entirely, I want to see if I can dig up a frame with a bowed - but not warped - headtube, much like Randy's PX-10. Unless it can pass the non-wrinkled frame test, I'm not going to buy it; it'll be a waste of money on a worthless novelty. If it does work on a slightly curved frame w/o any kinks (Randy's frame has technically proven it already, though I'd like to try it out too), then I'd see the point in it.

-Kurt

cudak888 

If you win it, let me know if you'd lend me the carcass to test it on this tool. It looks like an interesting bend - very little warping.

-Kurt

randyjawa 

Needless to say, I cannot comment on another bicycle, but this is the before and after story for my PX10. You will see that all was not necessarily well - at first.

rat fink

That Raleigh was utterly tragic, Kurt.

cudak888 

I read up on your PX10 - you lucked out with a frame that had not deformed out of round, and had simply curved downwards a bit. This tool is pretty much useless the moment there's a crease - even that silver Paramount is beyond hope.

If I could find a few more frames bent in the same manner as your PX10, perhaps I'd view the tool in better light.


All it needs is a new front triangle. Any framebuilder can take care of that. Since its silver soldered, that makes it even easier.

-Kurt