[CR]RE: CR Sup'Air Tubes, long and windy, but maybe interesting.


Example: Humor

From: "R Bulis" <RichardBulis@msn.com>
To: "classicrendezvous" <classicrendezvous@bikelist.org>
Date: Mon, 11 Oct 2004 09:08:03 -0700
Seal-Send-Time: Mon, 11 Oct 2004 09:08:03 -0700
Subject: [CR]RE: CR Sup'Air Tubes, long and windy, but maybe interesting.

Sup'Air Latex tubes. Long Story, but Rick Gaytan, you asked, (...and I get a good post in on CR): My partner (Russ B- helmet guy) and I imported those tubes in the late 70's and early 80's from Robert Boulain, a tiny operation in France. The original name was Imp'Air but we changed it to Sup'Air since that sounded better to our American ears. We also imported Mitsuboshi tires from Japan with the same brand until a certain SF bay area industry mogul using the same source shut us down. By way of education, most if not all, latex tubes back then were made by making a metal block with a straight holes running through it the length and outside diameter of the desired tube. The block is then dipped in a tub of liquid latex, allowed to sit....oh about so long, then pulled out. Latex sticks to the inside of the tube, and when dry, is pulled out by hooking one end of the now latex tube and pulling it inside out back through the hole. The tube is now cut to length and lap seamed and a valve installed. ( Oh, for pictures...) You can imagine the lack of quality control in this process and it was one reason latex tubes had a bad reputation. Mssr. Boulain's innovation was two-fold. One, he made his tubes by an extrusion process which evened out the wall thickness, and two, he developed a proprietary inner coating that sealed the tube making it "Imp"-ossible for air to seep through the walls of the latex tube, and his/our tubes would hold riding pressure much longer. Latex tubes of the day would need to be pumped back up on a long 4+ hour ride which was another reason for their disfavor. But the riding difference from latex tubes is quite noticeable. Boulain conducted some sort of testing, and he claimed 40% of the rolling resistance in a bicycle tire was contributed by the tube. (Pen-pals, flamers and nit-twits note: Debatable for sure, let's just say that there is some more stiffness in a butyl tube and thus rolling resistance. I don't need a bunch of emails to deal with, I am just telling a Proddoti Oldfarti story. Believe what you wish, or keep it on the list only, thanks.) I still use latex (Michelins) to this day, because they give more "bounce per ounce" IMHO. In the wheels of my crit bike, they feel like you're on fast light tubulars. I have them in my TT bike as well. They're light and really roll. However, like latex tubes to this day, they tend be be fragile especially when hot from rim braking, and when they let go, they do so in spectacular fashion. I was descending the Gross Glockener/Hoch Alpine Strasse in Austria last year, playing tag-a-long with a "train" of moto-boys who gave me perfect speed and braking cues as we plummeted down the North side. On the very last of 8kms of tight hairpins, I blew my front tire completely off the rim (sounded like a gun shot) and shards of latex tube went everywhere, including winding up around the hub. Fortunately I was in the apex of the turn at the time with no other vehicles around and I rolled to a safe stop straight off the curve to a picnic table with a startled couple eating their lunch. I cleaned up my mess, chunks of tube were everywhere on the roadway, and my rear rim was so hot I kinda burned my fingers to see what the conditions were there. The Vittoria CX tire was quite melted; the tread and side walls were a gloppy mess. I and the rims and tires cooled down and I pulled myself together and s-l-o-w-l-y finished the rest of the ride. This near death experience taught me to slow down the rest of the trip, and wish for big disc brakes. Finally, as to your tubes in hand Rick, my advice is do not use them. They are likely to flat at the first opportunity. If yours are in a plastic sealed bag and there is a little pouch sealed on the top side of the bag, that contains the requisite talc powder that all tubes, most emphatically latex, need to be dusted with upon installation. Those came in the later shipments. We raised quite a stir once when the customs agents opened a crate and all this white powder was evident. "Just what ARE you guys importing here?" they demanded. And I WAS gonna post something about Velo-Rendezvous!

Richard Bulis. Verdi Nevada.