sumgy

I have found a few threads mentioning it, but info seems limited and confusing.
Some say that "New SLX" and PRX are one and the same thing.
Some suggest that both PRX and SLX have spiral "ridges" inside the tubing, but I have also read that PRX tubing is more "ribbed" rather than spiralled.
This Facebook post suggests that PRX tubing is rare, and a conversation with a local framebuilder suggested that PR stood for Paris Roubaix.
I am also really interested to know whether the suggestion made by Veloseum that Giovanni Pelizzoli built these Concorde Preludes in PRX as mine is one of them.
According to the Concorde catalogue, the Prelude models were made of SL, and according to that catalogue, they never used PRX.

Carbonne TVT - Bonded carbon
Squadra - TSX
Aquila - SLX
Prelude - SL
EL35 - EL
MAX - MAX
Classic - Aelle
Colombo - Aelle
Mistral - Aelle
Astore - Cromor

Spaghetti Legs 

Wow I have never heard of PRX before. That is a cool bike. The sticker has “elica continua” which I would guess translates to “continuous helix”. I’m pretty sure SLX has the spirals just at the butted ends. I’m curious what you’d see shining a light and looking down your seat tube.

Wildwood 

I will fess-up to not knowing about PRX tubing.
Wondering if all the main tubes are round for their entire length?

gearbasher

Here's a chart with a little PRX info.


I own two Guerciottis. one PRX and the other TSX. The ride quality feels exactly the same to me

T-Mar

PRX was a development of TSX in that both used Columbus' Cyclex steel alloy and had helical ridges along the entire length of the top and down tubes. However, I'm not aware of what the exact differences were. Given the above tubing chart, it may just be a heavier gauge version.

sumgy

Yes, all the tubes are round as far as I can see.
None are crimped or ovalised.

sumgy

Thanks for this.
I think I saw your PRX Geurcotti in a post on here somewhere.
Any idea on why PRX seems to be so rare?
I reckon my Prelude is the smoothest riding bike I have ever owned (even when only running 23's).
It is also interesting to me that such a "rare" frame ended up in West Australia before I bought it from a guy via ebay.
When I got it, it had the remnants of a name on the top tube, but not enough to be worth saving when I got it painted.
Much of the top tube was also rattle canned matte black, and I had to get the fork straightened too.
The frame builder who straightened the fork was adamant that the PR stood for Paris Roubaix,

P!N20

For comparison, TSX is listed here as 1950g, so that would lend weight (!) to the argument that it's a beefed up TSX.

P!N20

Because frame builders weren't suckers? I dunno, there's a lot of marketing in cycling, 'buy this and you'll go faster', which is fine if it's something you can walk into a shop (or website) and purchase, but with frames who are you advertising to, the frame builder or the end user? I don't think any manufacturers were going to add a new model every time Columbus came up with a new tube set, (and there were a lot,) and I don't think there would have been many cyclists that just had to have those PRX tubes to the point they would get a custom frame built. TSX is rare enough as it is, but a PRX spin off is beyond niche.

I may be wrong, just my opinion, please correct me, etc, etc.

gearbasher

My theory for PRX being rare is that it was introduced at a time when steel was going out of style.

RobbieTunes

It's harder to say "PRX" than "SLX" or "salsa."

unterhausen

I agree, and also at that point in time, steel builders wouldn't go out of their way for a heavier tube set, even if needed. Much more likely to go too light.

KonAaron Snake 

Weren't there several generations of steel that came after PRX? All of the nivacroms? MAX, Genius, etc.

T-Mar

I'm more inclined to attribute it to steel moving in a different direction. In order to provide lighter weight and increased stiffness, Columbus' steel tubesets were moving to higher strength alloys such as Nivacrom, that could be drawn thinner and TIG welded in oversize and non-round shapes. PRX, being the older Cyclex alloy, seems to have been designed for traditional lugged construction, in standard imperial diameters. Basically, it wasn't state of the art and appealed to a smaller, niche market for traditional frames.