Any ideas on the posible tubing in this Zeus frame? Seatpost size is 26.6. The seat post says 27.2 but it has been filed to fit. Do not ask me why or who did it.
Thanks

Appears as if it may be too late to be a Zeus Zeus.

Looks as if it may date from around the time Razesa began making the Zeus badged frames.

Will look forward to reading the words of the experts...

When was that?

Have never known an exact year for this change. Have thought of it as taking place in the mid-'80's. From what have observed would make guesstimate of ~1983-84 for the transition.

The manner of the cycle's kitting is a bit of a dog's breakfast. A nominal KAS team bike would not have left the works with anything like this kitting. Some of the obvious non-original bits are chainset, stem/bar set, saddle pillar. From what can be seen in photos chainset appears to be a Zeus Gran Sport or Criterium triple while one would have expected a Zeus equipped machine to be fitted with a Zeus 2000/2001 double.

Rear mech looks to be Campag SR while front mech appears it may be Campag NR. Yet headset appears to be Zeus Gran Sport (part of Criterium road ensemble). Machine wears a MAVIC sponsor's transfer yet MAVIC was offering a full road ensemble by this date.

One possible explanation for the odd assemblage of bits could be that someone obtained it as a bare frameset and built it up with parts to hand.

Frame constructed of BOCAMA Competition 78 lugset.

Forum may have some members who recall details of the KAS team machines of this time who will be able to post.

Spanish bicycles of this apparent era typically used French threading and metric tubing, in which case a 26.6mm post is indicative of butted Reynolds 531 or equivalent. Measure the outer of the seat tube to see if it is 28.0mm (metric) or 28.6mm (imperial).

The different parts I know they do not really belong to the frame. I am just really surprised by the light weight of the frame. When you see it it doesn't look extremely special, but then it is extremely light. Any opinions on the quality of the tubing and frame?

KAS team operated 1958-1979, disappeared for a time and resumed play once again in 1985 for three years. Judging from what can be seen in pictures frame may date from 1978-79 time.

Frames were supplied by a number of different manufacturers over the period as described in this article:

Colnago Super 73 | Cycle EXIF

Do not doubt that your frame is likely Zeus. One dating aid might be the use of the Cinelli investment cast shell made by Microfusioni. Do not know what year they would have first employed these.

The company made use of this BOCAMA lugset for top models in the later 1970's.

This advert for the Zeus 2000 Supercronos (top of the line model) road machine of the late seventies identifies its tubeset as Reynolds 531SL:

How good were these Bocama frames? Trying to figure out if it is worth keeping or sell. So you think this frame was top of the line?
Thanks for all the information.

BOCAMA(BCM) is a brand name for frame building bits: lugs, crowns, etc. It is not a maker of frames. A few examples of their products:

wrt contemplating retension or sale of frame my first consideration would be "is it a good size for the envisioned rider?" if not, other considerations become moot.

I am considering keeping it, if it is a desirable frame and build. I have 3 bikes and this would be my 4th and my wife is not very happy. If it is a mid level frame, it might be better to sale, not worth the trouble. But if it is upper level, I would keep it and deal with the consequences.

Jose Manuel Fuente wants his bicycle back!

if that were mine (and it fit me) I'd definitely keep it! If you want to sell off the stem you can probably find an eager Colnago owner who wants it, looks like an ITM, true? Also would not recommend this but the water bottle might also be collectible to someone, but probably best to keep it with that frame.
Share some more pix of this!
BTW, that Cinelli IC BB shell has "FRANCE" cast into it, so I'd bet that indicates it's made for Metric tubing (but measure the OD of main tubes to confirm that) as to whether it's metric Columbus or metric Reynolds perhaps the fork steerer can help with a clue. 26.6 if correct MIGHT indicate a light/thin-walled set perhaps like 531SL...perhaps...

Seat post size is 27.

^then I have no idea, it's getting confusing^ a small frame would not use a thicker-gauge seat tube (like SP or 531 plain gauge which MIGHT take 27.0)...get a digital caliper and measure the ODs of those tubes as a starting point, at least that will confirm metric or Imperial.

It is metric, french threads. Right now I do not have the bike, it is at the bike shop.

as mentioned by T-Mar above, if frame produced in Spain it is a few years too early for ISO/BSC standard. at this date one would expect metric/BNA dimensions.

one possible cause for the apparent contradiction would be if assembler reamed seat tube in order to have to take down pillar they wished to use less.

OTOH we do not know that it has not been the recipient of a respray & retransfer...

I am from Spain so my English is not perfect. What do you mean by"assembler reamed seat tube in order to have to take down pillar they wished to use less."
Thanks

We know someone has reduced the diameter of the seat post in order to fit it into this frame. My statement suggested possibility that they may have enlarged inside diameter of seat tube as well, in order to accomplish this fit.

As stated by T-Mar so articulately above, on a metric dimension steel frame with first quality tubing one normally sees a seat post diameter of 26.6mm.

Apologies for any lack of clarity.

So is frame presently at Link?

While this is possible, it seems unlikely. Given the presence of a Cinelli BB shell, it is almost certainly a premium grade tubeset for the era and likely has not been reamed any more than to restore the tube to round and spec diameter. Metric tubing, in conjunction with a 26.6mm post, makes butted Reynolds 531 the most likely candidate.

Casting about for explanation of poster's statement that seat tube interior measures "27mm."

I am going to keep this interesting frame. Want to restore, but not sure what tubing decals I should use. We have 3 possibilities, 531 butted, Durifort or Bocama.

Bocama did not make TUBING so I think you likely possibilities are
Reynolds (Zeus used this mostly, but not so sure about Razesa)
Columbus (they made metric tubing)
French-made brands, such as Vitus/Durifort
Besides measuring the ODs of the 3 main tubes, you should also investigate the inside "butt" or bottom of the fork's steerer: look for 5 shallow spirals...carefully examine the steerer for any BRANDING on the outside, such as a Columbus DOVE or the name REYNOLDS...the stamps, if there, will be very faint so use strong light.

wrt tubing employed to construct the frame one spot you could check without disturbing the paint finish is the steerer. the outside of this tube is often stamped with the maker's mark.

if frame presently at a bike shop you could telephone them and ask them to check the steerer for you.

in the mid 70's I built a Frame Filed off the Z on the fork crown.

That a company like Bocama Made a Lot of frame components for Zeus with their Logo on it,

Seems Unsurprising.. Order enough similar parts from a company Now,
and they would put your name on it.

How do we even know it is a Zeus?