FW: [CR]HELP - Determining tire size

-----Original Message----- From: DoubleB [mailto:swiftybjb@rogers.com] Sent: Monday, February 21, 2005 8:04 PM To: ternst Subject: RE: [CR]HELP - Determining tire size

Ted,

Clear as mud. But there were 27 inch tubs (or sewups as you call them on this side of the Atlantic), I know, I raced in England for 10 years in the 60's and 70's before coming to Canada and all our sprint wheels and tubular tires were 27 inch. I got these tubs from a bike shop just north of Toronto that was closing down, he said he had these tires for years and thought that they were 650C, which is not possible because if they were they definitely would not go on a 700C rim (622mm rim for 700C vs 571mm for 650C). I know that 27 inch is 630mm, and I was thinking that the small 8mm larger difference was what was making it easy to fit these tires to the 700C rim. I'll use them anyway, I'll just put double the glue on and I won't go around any corners!

All the best, and thanks for the email.

Brian, Toronto

-----Original Message----- From: ternst [mailto:ternst1@cox.net] Sent: Monday, February 21, 2005 7:49 PM To: BJBooth; classicrendezvous@bikelist.org Subject: Re: [CR]HELP - Determining tire size

Brian: I'm sure you have standard 700 / 28" sewups. Smaller sizes are almost always marked, ie: 26". I've never seen 27" sewups. The problem is that the bike industry is bereft with holdover and misnomers of over 100 years. The French were the true metric and the lost the int'l dimension war. Somehow 28" became the standard in the 1890's era and clinchers and sewups were same sizing ,and the 700 was the metric equivalent. The 28" dimension has held on even till today and many sew up tire companies use that number to this day. Our 700c clincher and the sew up rim diameter are basically the same, about 5mm smaller than the 27" rim but the 28" sewup is 700 in size and smaller than the 27. Many of the 28" tires are measured outside diameter, the rims are 700 so that often a 28" tire will fit a 700 rim, or visa-versa. Now that this is perfectly clear you'll have no problem telling your sizes apart.You just have to know what the hell you are doing. That's where many years of experience has helped, or even better for newer people to our fun game, hobby, sport, many afficionados will refer to Sutherlands Guide. Remember that sewups come slightly looser and tighter from the companies, and the looser fit saves the pressure on your eyeballs when you are stretching it over the rim. Clinchers are the same, some are finger busters, and others are a breeze. Confidentially I suspect it's an English plot to bring back Whitworth sizing and the memory of Dunlop and restore Brittania and rule the waves again. Its the Victoria's Secret of Cycling. Ted Ernst Palos Verdes Estates, CA