The long and winding road........

@Lascauxcaveman

Good Gawd, @Wildwood, did you really drop this poor thing on me last May?

I'm sorry it's taken me this long to get to the assembly process, but it's on the stand now.

Couple of issues not addressed yet: let's start with the threading on the top of the steerer tube.



Obviously, the first couple courses of thread here on the fork steerer tube are buggered; the steerer was likely dropped or banged on something while the frame's rear triangle was being crushed, spindled, folded and mutilated. No chance at all of spinning on the top cup or fixing nut of the headset in its current condition. Like the BB (and both ends of the head tube) the end of the steer tube is slightly ovalized as well.

My ham-fisted-caveman-mechanic's inclination is to use the flat edge of a cut-off disc on my Dremel tool to chamfer the first two courses of steer tube thread down to metal shavings, creating a fresh new taper on the end of the tube and then chase the leading edge of the thread with an Exacto-knife or something to get the top parts of the headset to thread on. I've done this sort of thing on many a buggered or cut-off bolt thread on various non-bicycle projects, but never one with a thread pitch this fine.

What say you, oh jury of my peers?

Just make sure the loss of material doesn't affect the HS to be installed. Different stack heights and all that, you know.

I don't think it's an issue at all originality-wise as what you're planning doesn't sound too invasive.

DD

You might use a steel seat post, the tapered bit at the very top, above the 22.2 mm section, to get it round again. Use grease so it doesn't get stuck.

Don't they make a file that's specific to fixing damaged threads? I'm pretty sure I've read about it on this forum.

Nice job Gugie. That's what the Park FFS (Fork and Frame Straightening tool) was designed to do. I have one of those and it's a whole lot easier to use than a couple of 2 x 4's.

I've checked the alignment of every bike or frame that I own. If it's not too far out I can realign it at home, otherwise I take it to a frame builder friend's shop and use his layout table or pay him to do it for me. I let him do my forks and pay him because he has all of the jigs etc.

We sold some Zeus bikes in the 1970's. The top Zeus model from the early 70's was made with metric sized butted Reynolds 531 main tubes and Durifort forks and stays. That combination was also popular with many better quality French builders and manufactures from the 50's until the early 70's.

Durifort was low alloy seamed steel tubing with about 2/3rds the strength of Reynolds, Columbus and 4130. The main tubes were butted which increased the strength. The wall thicknesses of the Durifort tubes was about the same as heavy gage 531 and Columbus SP tubing.

We had to realign the rear triangles on a number of out of the box Zeus bikes. The rear stays were dead soft the first time they were moved. The toughness increased after each time the tubes were bent. By the time the frame was aligned the stuff was as tough to bend ad Reynolds or Columbus because of cold working.

BTW - Zeus bikes used metric threads and took a 22.0mm stem. The standard Zeus headsets were far superior to the Campy headsets of the day.

We sold a lot of bikes with Durifort frames. The bike that I put the most miles on was a 1975 Bertin C34 with an all Durifort frame like the one pictured. I never saw a frame failure with Durifort tubes.

Yes, I found it!



read about it here: https://www.parktool.com/blog/repair...icle-section-2

Thanks, and good to see you around these parts again, Chas. I was beginning to wonder where you were!

Damn, a tool I don't currently have. I need one!

Edit: I need two, SAE and metric!

Edit again: Available on Amazon prime! Ordered!
[MENTION=280039]Lascauxcaveman[/MENTION], consider a trip to Atelier Gugie sometime in the near future, and perhaps coordinate with [MENTION=265188]Andy Antipas[/MENTION] for a frame delivery, separate issue.

One?

Oops, looks like you're right. The two Cinelli (22.2) stems Wildwood gave me to try won't go in the steerer tube, but the old Peugeot one I have works.

So we're looking at a French threaded headset, meaning the standard threaded parts I have won't fit even after I clean up that messed up thread on the end. And the thread-cleaning file linked to above won't do that job because it only goes down to 24tpi? Comparing the threading on the Zeus steer tube to another 1" threaded (Trek) fork I have lying around makes the threading on the Zeus steerer definitely look like a slightly higher TPI count. They don't mesh when held together, thread-to thread.

Anyone got a nice Zeus headset they want to toss in for this project? Or the top half, at least. Barring that, any old French-threaded thing? I know I can get one from VO not too dear, and a guy on 3bay has some NOS Ofmenga ones for $23 shipped.

Somehow missed this during the original go around, so I am dredging it up again. I know its not something your normally going to go after but it seems to me you could check head and seatube twist with an angle finder, frame chucked up in vice, check each tube and voila in degrees easy peasey. Might be good to know when the frame doesn't respond to the alignment as expected and its off mare than a bit.

You can make a chaser from an extra top nut, threaded cup or race, just cut some sharp slots in it, use something sharp like a right angle pick to massage and spread the bad threads, carefully bevel the start of the threads a bit then carefully work the chaser on using anti seize for lube. I have done this many times, 100% success at the track, on the road, in the driveway and on the job.

Glad to see it dredged up, happy seeing a bent frame with a happy ending. You can eyeball the head tube against the seat tube with some back lighting. That's how Bob Jackson's people do it. I recently purchased a used frame table, which is of course a more exact way.

Sounds good, angle finder might still be quick and dirty.

Ah, a DIY die, in other words. I don't have any French threaded any-of-those to work with, though. So I may have to go with my original plan.

@Wildwood, what do think of this thing for the top half of the headset? It looks period correct anyway. The VO parts you gave me work just fine on the lower half; only took a little honing and finesse to fit it all in. The top half of the VO set is a no-go, being ISO threading, not French.

That's what the co-ops are for. And for what its worth I would encourage everyone hear to keep this in mind for BB's, headsets, pedal threads(made out of old spindle's) and anything else when the threads get boogered, it does require a sacrificial part so there's that but then you have that tool from now on.

Zeus headsets have a 41mm stack height just like Campy NR. They were much better quality than Campy - through hardened to 60rc.

Velo-Orange headsets have a 41mm stack height, so do Stronglight S5 and Tange Levin.

Tange made metric threaded headsets but they're hard to find.

The Tange Levin CDS is a very nice headset for the money (~$20 USD). Through hardened with plastic dust seals. The stack height is only 33mm.

Stronglight V4 headsets have a 37-39mm stack height. The Stronglight A9 would be a good choice too. They have a 39mm stack height.

Someone is selling some cheap steel Stronglight A9 headsets on eBay that are painted black and have standard ball bearings.

Two pictures show how to easily measure stack height.

There are 3 sizes of thread chaser files coarse and fine inch size plus metric. They can be a life saver.

BTW, DON't cut off the top od the steerer - use spacers instead to make up for any space under the top lock nut.

The last pic shows the difference between 1mm and 24TPI pitch. 24TPI is close enough to 1mm for chasing just a few threads

Aye, look back at the thread, available in SAE AND metric.

[MENTION=73614]rhm[/MENTION], yeah, bought one of each.

Maybe get a sacrificial top nut, cut it in half into two "C"s, then clamp those around the threads below where they are damaged, and then just unscrew it.

WARNING: TECHNO GEEK STUFF.

SAE = Society of Automotive Engineers was the US Fine Pitch Thread Standard.

USS = US Standard was the US Coarse Pitch Thread Standard.

While the terms are still in use, both of those standards became obsolete on November 18, 1949 when the Unified Thread Standard (UTS) was adopted by the Screw Thread Standardization Committees of Canada, the United Kingdom, and the United States.

While Canada and the UK switched to the ISO Metric Thread Standard about 1960, Inch sizes are still standard in the US.

Metrification is slowly happening in the US. Thomas Jefferson wanted to adopt the Metric System in the late 1700's. DOH!

The current US Thread Standard are:

UNC = Unified Coarse is still the US Standard for Coarse Pitch inch size threads.

UNF = Unified Fine is the US Standard for Fine Pitch inch size threads.

There are a lot of other UN Standards such as UNEF = Unified Extra Fine, UNJ = Controlled Root Radius Aerospace Threads and so on.

There are 3 different thread files available - 2 for Inch Pitches and 1 for Metric.

For chasing 2-3 threads at the end of a part, a 24TPI file will work OK for 1mm Metric threads.

BTW, most of the pre ISO thread standards were based on mercantile motives rather than any technical advantages. The Brits and their empire had Whitworth and other arcane standards, the French - Sellers and S.I. - System Français, Germany - their DIN standards, Japan - JIS and so on.

@Wildwood, this is a 1970-1973 Zeus Competition Ref Z-52 frame ~60cm. As I mentioned above, the 3 main tubes on these frames were butted metric Reynolds 531 with a 1.0mm x 0.7mm wall thickness. Back then Reynolds called this their "Sprint" tube set.

The wall thicknesses of these tubes were about the same as heavy gage Columbus SP tubing.

Back then a lot of production frames were made with these heavier gage tubes because it lessened the chance overheating the tubes when brazed by less experienced employees.

The forks and stays were Durifort tubing which was about 2/3rds the strength of the alloy steels used in Reynolds 531, Columbus and 4130.

As an aside, Durifort butted main tubes had a wall thickness of 1.1mm x 0.7mm, slightly heavier than Reynolds 531 Sprint and Columbus SP. the next Zeus model down from the Competition plus the P66 Cyclocross bikes were made with all Durifort tubes.

After 1974 Zeus started making all Reynolds 531 frames with long point cutout lugs. They also switched from Cinelli style sloping crowns to the then new investment cast Zeus 2000 crowns. The overall cosmetics improved too.

Some Zeus components were much better quality than the contemporary Campangnolo parts. The Zeus Gran Sport ref 61 headsets for example. We compared the cup and crown race hardnesses between Campy Record and Zeus. Some Campy headsets were only 48Rc while all of the Zeus bearing races were 60Rc.

Zeus used stronger hub axles than Campy. We saw a lot of bent or broken Campy rear axles in the mid 70's. Zeus and Campy axles, cones, spacers and lock nuts were that same size except for the threads. Campy use bastardo 10mm x 24TPI thread while Zeus was industry standard 10mm x 1mm. We just replaced the whole axles with Zeus for customers who were having problems with their Campy rear hubs.

Zeus pedals came standard with alloy cages at half the price of Campy steel cage pedals. They had rubber O-Ring seals on the threaded end too.

Zeus Criterium fluted 2 bolt seatposts came out before Campy SR and were 1/3rd the price.

The first Zeus ad below states Reynolds 531 frame but the second one lists Reynolds/Durifort frames.



[/QUOTE]

[MENTION=61614]verktyg[/MENTION] - your authoritative input on model and year is greatly appreciated.

I have found the heavier gauge tubing in these larger frames, suits me well.
Will be looking for Zeus rear hubs.
Kudos to you.

[MENTION=22396]Wildwood[/MENTION] requested an update, so I'm sharing my response here, as it has some questions for my fellow vintage mechanics. Stuff I'd like you weigh in on, if you have any guidance, I've marked in red:


1) Got some Zeus brake levers and calipers from [MENTION=324747]Stevensb[/MENTION]; they're pretty cool! Need hoods though.



2) Got an English threaded adjustable cup in the NDS of the BB. It felt a little tight going in but at no time did it feel like I was cutting new threads. Taking it back out, threads look solid. The fixed side is even tighter, so I haven't yet tried to force it in, but I think that's what it's gonna take. When I attempted the fixed cup, it went in about 5 turns against very stiff resistance, I backed it out, and it doesn't look like I'm cutting new threads there either. I think the BB is just a little ovalized. Want me to run it across the street and see if the bike shop can chase the threads? Probably a $30 shop charge there, if they have the thread cutter.

NDS:


DS:


Referencing Sheldon's Mix-n-Match BB guide, unless somehow it's "Raleigh threaded," it doesn't seem possible that this BB is threaded anything but English, as per his chart English cups don't seem to even sorta-kinda fit any other standard, except very loosely. There's nothing loose about the way these are fitting! I'll run it by the Forum tonight.

3) Got the Frenchie Ofmega headset cap assembly off 3bay (which we needed because the steerer tube is French threaded and the VO headset you gave me was English). I cleaned up as best I could the bungled threads on the steerer tube (this bike's a mess) but now it threads on. I've never installed a headset like this, but it looks like you're supposed to fit the top part of the headset into the head tube by threading it onto the steerer tube and letting it pull itself in as you tighten it down. Then lock it with the threaded cap I'm holding in the pic. Anyone know otherwise, let me know.



I'm learning a lot here, albeit slowly. I keep procrastinating because of multiple thread problems which I fear I may make worse with my hamfisted mechanicking. OTOH, hamfisted may be the only thing to get these parts to thread.

Cheerio,
Caveman.

caveman-

Reciclone in Spain used to make replica Zeus lever covers. The site link is here. You may want to email a photo of your lever style to confirm availability. I have used Jordi's Mafac replica hoods and they were nice quality and a perfect fit on the lever body. I think you need to press fit the upper and lower bearing races (there is a special tool for this) and then the moveable cup should screw down onto the bearings in the upper race, the lock nut then screwing down on top. Good luck with the process - looking good so far.

Caveman,

A trip to Atelier Gugie might solve all of your woes.