mikewebber2010

Does anyone know about the threads used on early Zeus frames
I recently bought a 1960's Zeus. It has Nervex Pro lugs, and had a mix of 1960's parts on it that make me think mid-60's.
I have now taken the original Zeus BB cups out - thankfully neither side was seized, but the cups are not marked with any thread info.
Here's the weird thing - both sides are a right-hand thread, and they appear to be 1.37 x 24T. The drive-side cup is exactly that - two spanner flats on a fixed cup (no lockring)

I can thread other cups with that thread into either side - Are other thread sizes close enough that I could have this mixed up?

Has anyone ever struck this - and where can I find a replacement as this one is quite worn?
Thanks from Mike in New Zealand

20grit

From what I've read Zeus used French threads. Don't quote me on that.

dbakl

Yes, they are French, and can be reversed...

capella lugs

Sheldon Browns chart here: https://www.sheldonbrown.com/gloss_bo-z.html#bottom shows pretty clearly what might be going on i.e.- the right hand and left hand threads, and also the similarity of thread sizes from english to french to Italian.
I guess it pays to be careful not distorting the threads any further until its clear what the original thread actually is.

( A friend has a frame with a similar bottom bracket bracket, but it looks like someone has complicated the puzzle by managing to cut a left hand thread on the fixed side that runs alongside the existing right hand thread ! )

dbakl

Zeus frames are certainly French (though they made bottom brackets in all threads). Here's how one I rebuilt recently arrived: cups reversed, and after repack, corrected.

I'd think it difficult to put a English or Italian bb in a French frame, especially reversing the threads...

bobbycorno

...but maybe not so much in a Swiss-thread frame: my Mondia came with a no-name Taiwanese cartridge bb, which I'm pretty sure is only available in English thread, not Swiss.

SP
Bend, OR

yeslek

If your bottom bracket spindle is marked (as and example 118x55) the 55 is the standard 68 cm width, and more than likely French. if 118x57 this is 70cm and Italian.
Check your lock ring, will it thread up on the fixed cup? Meaning either French or Italian, since both thread the same for both cups.

yeslek

With the CUPS not marked again a sign of them being French.
I have a French threaded cup set, but would like a zeus english cup set (BSC stamped)in exchange.
do you need the whole bottom bracket set?
I have a lead on zeus 118x55c that I can add my french cups to for $60 USD not including shipping.

JohnDThompson 

No, French is 35.0mm x 1.0mm while Italian is 36mm x 24tpi.

A French cup would be too small to engage Italian threads.

San_Son

I have a Torrot with a Zeus BB. I've checked the cups with a pitch gauge and they fit in the metric system part in the 1mm gauge so they are 35mm x 1 mm. The funny part is that the fixed cup is left-handed. This means I have an spanish bike with a suisse BB? I´ve been digging in old Zeus catalogues and it seems Zeus did french, british ans italian standards but not suisse. Any idea? This really wierd or I´m missing something?

dddd

You got yourself metric SWISS threading going on with that Torrot frame, nothing French about the bb threads.
Yeah, still metric, but with superior left-hand threading on the driveside.

The frame maker either ordered the bb shells with Swiss threads, or with no threads (and tapped them themselves).

I've "forced" an English-threaded BB-UN72 bottom bracket into a 1979 Peugeot's Swiss-threaded frame, but it took considerable back-and-forth action with a long wrench to work it in fully (the cups being aluminum, no alteration to the frame's BB actually occurred).
I don't think that it would have worked using a bottom bracket having only holes for a pin tool instead of robust splines like the Shimano BB.

San_Son

I see...Got myself I tough piece of gruyère... So I won´t be able to use the whole Zeus crankset I've already bought because it is french (right-right)

What aluminum cups BB will you suggest me? The Torrot has a 130 mm distance between dropouts and it came with double chaingring (53/42) with a 5 speed freewheel.

JohnDThompson 

You have a couple options. You could ream the shell and cut Italian thread to use Italian thread cups. You could use a Phil cartridge bottom bracket with Swiss thread mounting rings. Or, you could use a threadless cartridge. Velo-Orange used to offer one, but I don't see it on the web site anymore. SunLite/YST still offers one. Historically, they don't seem to be the most durable, but they're less costly than the Phil, and available. And IRD makes Swiss thread mounting rings for their cartridges.
https://phil-wood-co.myshopify.com/c...m-bracket-cups
https://www.amazon.com/Sunlite-Threa...004E3QNXM?th=1
https://www.interlocracing.com/shop/...2839#attr=1107

San_Son

And what do you think about this:
Search for: phil-wood-y-shimano-bottom-bracket at velo apocalypse (still can't post any links)
I can buy a Shimano UN72 around 30€ and add it the swiss phil wood cups (around 65€). However still think is a lot of money to spend on that bike.
Also, because I want to work repairing bikes I think I can buy a BSA rethreading tool (Ciclus, around 110€) and fit the UN72.

Don´t you see it viable to force a Shimano catridge in like dddd did?

Thanks a lot for your suggestions. I appreciate them a lot

sbarner 

French being 35 mm diameter is a little over 0.007" larger than British, which is about the thickness of two sheets of 20 lb paper. Not much, especially considering the loose tolerances of many European manufacturers. The 1.0 mm pitch works out to be 25.4 threads per inch, vs. 24 TPI, so what you have when you put a British cup in a French or Swiss BB shell is a cup that starts to thread in easily (perhaps even loosely), but gradually tightens up as the thread pitch mismatch comes into play. Bicycles being what they are, it should work out just fine the vast majority of times. I would warn a customer before doing it, but as a way to get an inexpensive bike back on the road cheaply and quickly, I would also advise they go for it.

San_Son

Well finally I've decided to buy the IRD swiss cups and install them on a economic cartridge, VP-BC73 that jrstewart3 has checked its fit with. Anyway the fix has gone pricy because there are no IRD retailers in Spain and I got to bought it from Nederlans (54€! total with shipping costs) Another reason to have chosen IRD is that you don't need to buy an specific tool for its installation as with the Phil Wood ones.
As I getting near to my 10th post I will be able to finally show you some pics when I get there with the installation. Thanks a lot to everybody

JohnDThompson 

That would work, but the UN72 is discontinued. If/when it fails, what then?

That won't work. The ID of a Swiss thead bottom bracket shell (35mm) is too close to that of a BSA bottom bracket shell (1.375";34.9mm), so the threads would be very weak, if at all functional. You'd need Italian thread taps (36mm ID) and a reamer to get functional threads.

Maybe. But that's just nasty! 🤨

dddd

If you can find a UN72 in a known-proper spindle length... that's maybe an issue because you have to either figure out (or test-fit-verify) the mis-match what with JIS vs ~ISO spindle taper, and with the UN72 likely having no spindle offset in the length needed for your Zeus cranks.

In my case, I had experience using JIS spindles with ~ISO cranks, so I knew what length I was likely to get good clearance and chainline. So I had little to risk in terms of possibly damaging the threads on the now-rare UN72 bottom bracket.
It also worked out well because I had the right tools needed to get the cups fully settled/bottomed in the bb shell (it's been good for 12 years now).

Buying swiss-threaded parts is easier and doesn't cost all that much versus the labor involved.
But you still need to calculate what spindle length of (likely) zero-offset bottom bracket cartridge to buy. I'm guessing 113mm would very likely give more than the minimum needed clearance at the chainstay and provide good chainline if your freewheel sits close to the driveside dropout as it should. A cup spacer can be added later if it doesn't, or the cups may be of the floating/flangeless type and so readily adjustable for chainline.