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Naive question here, I've never used or even seen a tubular tyre - I always thought they were just doughnut shaped tyres with a valve sticking out. And that's it, no tubes.
They apparently have inner tubes, so if you puncture you need to open the thing up to mend both the tube and the tyre? What is the reason for needing the tube / tyre combination, rather than just a tyre?
[url= http://clementcycling.com/pdx-tubular-2 ]Not all tubulars have inner tubes[/url]
Originally, tubular tyres (or "tubs") were constructed from a silk carcass with a tread "painted" onto the circumference with liquid rubber. In order to maintain the airtightness, this carcass was stitched around a very lightweight inner tube, so in effect it became a one-piece "tyre".
Tubs were then glued onto a rim with a concave surface using shellac.
Don't confuse "tubular" with "tubeless" - different concept. Tubeless tyres are generally a clincher tyre fitted to an air-tight rim - this technology only really cam about with the the advent of pressed steel and later cast alloy car wheels.
Tubeless tyres fitted to spoked wheels on bicycles and motorcycles still need a sealing medium such as a latex solution or mousse.
The Badger Quote in 3...2...1...
Thanks. So back in the day, it was difficult to make an air-tight tubular tyre carcass, hence the tubes. Nowadays, it can be done in a oner, if you like.
A silk tyre is not something I've seen before, I guess this must look a little different to how one might imagine.
A silk tyre is not something I've seen before, I guess this must look a little different to how one might imagine.
Nowadays it's all polyester, nylon and polyamide, but essentialy they're the same as normal clincher tyres, to make a clincher you start with two hoops of kevlar or steel which forms the bead, then wrap the carcas round them a number of times (singleply is usualy overlapped to give 2 layers in the sidewall and 3 under the tread where they overlap, dual ply would be an extra pass so 4 on the sidewalls, 5 under the tread), then put it in the mould, expand it to the shape of the tyre and add the rubber. Tubs are often vulcanised now (the above process), but some still get made the old way of forming the tube of tyre carcas then gluing a seperate tread to the outside.
Thats the two extreams, theres more than 2 ways to skin a cat (or make a tyre) though.
Tubs are usually lighter, roll better and wheels are lighter. I used to run my tubs at 180psi for minimum rolling resistance but now tend to leave them at 140.
The downsides are they are difficult to repair (unless you have plenty of time and like a bit of sowing) and they're not cheap.
Oh and as you glue / tape them on, have faith they won't roll of the rim.
Ooo, I like a bit of sowing (and reaping....) 🙂