Anonymous
Anonymous asked in SportsCycling · 1 decade ago

tubular or sew-up tires 27inch or 700c?

I have been a cyclist most of my life, but have never owned tubular tires or ," sew-ups as they use to be called here in the U.S." Many old Schwinn Paramounts from the 60's came with 27inch sew-up tires. Today 700c is the standard size on road bicycles. This is my question do tubular tires, "or sew-ups", come in 27inch and 700c sizes? If there two sizes, where do people who own the older 27 inch bicycles wheel sets get their replacement 27 inch tubular,"or sew-ups as they were called here in the U.S."

I know from memory that sew-ups were mounted on special rims and a special varnish was used to help hold these tires to the rims. I was never able to own a bicycle that had this type of tire and rim set, but cycle racers back then all used them because of their low rolling reresistants. The sew-ups as I recall were sold by weight and used silk cords, the ones mounted on track bikes were inflated to as much as 150Lbs. air pressure.

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  • 1 decade ago
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    700c is 622 mm

    27" is 630mm

    There are no available 27" tubulars, but many of the 700c could be stretched to fit.

    The 650c bike has 3 tubulars (Vittoria and Tufo) still available and a much more authentic ride quality.

    To duplicate the tubular feel, we have 2 clincher options for you:

    Tubular road feel?

    1) Rivendell's Panaracer Roly Poly (or cousins) with a featherweight racing inner tube that was designed for a 25mm tire.

    Since the Roly Poly is 27.2mm, it may not fit your race bike, but it is an authentic size with near-identical ride and parameters, such as a round casing and the rubber is not piled up in the middle--round secure tubular feel on cornering.

    This is the only tire its size with such a high inflation pressure, as seen on road tubulars.

    Tubular race feel?

    2) Serfas Seca RS combined with Michelin featherweight 18-23mm inner tubes, will duplicate the speed and ride of tubulars, and the pressure range is up to 130 pounds.

    See roadbikereview.com for info.

    At 210 grams, these cushy, very round, road tires really hang the corners--very much the tubular ride.

    To duplicate the tubular feel, firm riding botique wheels will not do.

    The wheels must have at least 20 evenly spaced spokes plus some shock absorbing ability. Neuvation's 24/20 R28 SL2 wheel set or similar is a good guideline. http://www.neuvationcycling.com/wheels/r28sl2.html

    Tubulars work differently than [most] clinchers.

    On labratory surfaces and perfect pavement, the clincher is far faster. However, in real life and rougher pavement, the cushy ride of the tubular is faster because the bike rolls over abberations instead of "pushing" them.

    Hit a patch of gravel while cornering with a hard clincher and you go into the ditch. Hit a patch of gravel with a tubular [or very rare clincher] and you don't go into the ditch.

    There's a pretty big difference in safety when the tire is able to navigate road abberations. . .or not.

    Sprinters once preferred tubulars because of their ability to accelerate faster. Today, we have ligher weight wheels (mentioned above) and today's clinchers have Kevlar or Aramid beads, so this difference is moot.

    So that Serfas tire + featherweight tube + Neuvation wheel combination I mentioned can let you enjoy the old school feel, lightening bolt zip around the corners. . .every day, and nobody will know unless you tell them.

    This system on similar Rol 20/20 wheelset added a Cadillac ride, derring-do cornering, and scads of speed to my own modern road bike.

    For an even more authentic ride, a wider cassette, like an Ultegra 12-27 9 speed with a "compact double", or a mountain tail like Trek's pro tourbike (11-32 XT with LX M571 SGS mech)with a standard "road double" crankset.

    *My bike uses an XT Top Normal SGS rear derailleur onto a factory standard 105 STI road shifter. LX M571 has similar weight and higher efficiency (no Ultegra sealed bearing gimmick). Oh, and the Dura Ace chain was required because of fit vs efficiency on the 12t and 11t gears.

    Either way, shifting was more sprint centric, the bike did not have to drop chainrings for hills, and action was faster.

    *Faster action is the hallmark of old-school performance bikes. The machine gun sound and speed of Shimano's best mountain rear drives sounds and feels just like old Dura Ace.

    My friend, who is a racer and rides Campy, suddenly got big eyes when he heard this classic sound on a downhill and had to spin like a whirlwind to keep up with my relaxed pedaling.

    *Sora can use SRAM's PG850 11-32, PC58 chain and that same LX derailleur; but, you really should switch to an all-alloy crankset for a more authentic high-efficiency experience.

    *Notice that 11-32 cassettes have classic 6 speed road bike gears in the center.

    Cockpit and leverage:

    Plus some Maaes bend Nitto handlebars (see rivbike.com for ideas), can give the modern road bike an old-school feel with no loss of speed and possibly considerable gain in distance.

    Use the narrow 40cm width handlebars for areo.

    Also available at aebike.com

    *Those handlebars have a very large "half circle" drop section and you'll need something like Profile Designs H20 lightweight performance riser stem (90mm was the previous standard) to adapt the old style handlebars to a modern bike, for an authentic and fast ride.

    Don't worry about the stem angle, just use one with enough extension for your preferred reach, and it will not subtract areo performance.

    It will facilitate longer distances.

    *raises the height to bring the lower, large maaes bend drop grip up to what you have currently.

    *Maaes bend plus shorter extension is important because it speeds up the steering to make use of the extra capacity of tubular tires or the few clinchers that perform like tubulars.

    Well, if you followed all of that, you'll have an under 20 pound super comfy race bike that makes a quicksilver sprint, rampant uphills, and a breathtaking fast dash around the corners--just like they used to do.

    See also Roubaix applications and bikes.

    Specialized Roubaix or any Schwinn road bike will duplicate the old school ride, but you'll need 1 size small (usual for modern, ergo, "cross fit" bikes) and that handlebar treatment above.

    Roubaix wheels and other engineering came from a time when the races were on rough roads.

    Rough roads would "leak" your strength out at the handlebars for a "slapped in the face" sensation and last place on race day.

    Roubaix engineering softened up the ride, added extra sprint speed, and it put your power into the rear of the bike instead of wasting it on the front.

    Just this year, the "up and out" time trial grip came back into style. "Up and out" works as well today as it did when it was new for the first time.

    Back then, it was for the reason of pressing you into the seat instead of excess sliding + posting that "down and close" arrangements caused on bumpy roads.

    Today, we find out that it also survives the wind tunnel. ;)

    So, it isn't about one piece of technology like Tubular tires. It is about a system that was designed to protect the body, thus enhancing stamina and distance performance.

    Old race bikes sprint like mad, shift with a bang, and corner with no need for brakes (tubular ride). Gearing and steering at that time in history was all about fast action.

    Recently, it is back in style.

    I hope I gave you some ideas. Go enjoy!

  • 1 decade ago

    yea, i beleive that 700c is sew up size and 27 is "tubular" regular size. and yes sew ups require special rims and that glue stuff and silk cords. right on, guy, finally somone on this site that isnt dumb. :) and for my opinion, sew ups are better, but they are the costly option, if u dont have the money then tubular tires are just fine, nothing wrong with them, just get the lowest width possible, and slick tires, try for a low weight too, as rotating weight on a 27inch rim will... well lets say this, 1 pound of regualr weight on a 27 inch rim i like 2 or 2 1/2 pounds rotating weight. hope this helps man!

  • 4 years ago

    Sew Up Tires

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