grant40

I have a 26 inch Mavic tubular road bike wheel and the tire that came on it is a Vittoria Juniores, but it is falling apart and I don't think that it can hold up an adult.
Are 26 inch and 650c the same in terms of tubular tires as I found more results for 650c than 26 inch.

rosefarts

Someone more knowledgeable will be by shortly but
Most 26" tires are one size, 559mm
27.5 or 650b are another size 584mm
650c is a nearly extinct size from the 90's and early 00's for small people and triathlon, and you've never seen one in tubeless 571mm

Edit to add, you said tubular, not tubeless. If that's actually what you meant, I'm surprised since I never have heard of a tubular 26" tire but it may have existed. Very few tubular 650c but they did exist back in the day.

Doesn't change my earlier point, they aren't interchangeable.

veganbikes

Without info it is tough to really give you much.

26" can refer to about 12 or so different ISO diameters. Probably in your case it is 3-5 or so possibilities when saying 26 road. Though if memory and google searching is correct on the tire you mentioned it would be a 650C which is less common these days but still available though Tubulars might be tougher aside from the same that you have but made more recently. Look on the tire and check the ISO number and then get a tire based on that.

For some of the best help the lateSheldon Brown and his Cohorts have a lovely website still running with all of that info and more: https://www.sheldonbrown.com/tire-sizing.html

Leisesturm

Bottom line: no, 26" is not the same as 650B. Not in clinchers and not in tubulars. And a bike that is designed around a 26" wheel will probably not accept a 650B wheel. Things are different with the giant tires but a racing bike won't have clearances to spare.

BlazingPedals

Tubulars are mostly 700c, with a few 650c out there. A tubular rim will not take a regular tire, even if it's the same iso size - tubular rims don't have beads for regular beaded tires.

It's funny how people always assume a 26" question is 650b, and refer to 650c as 'obsolete.' Up until about 5 years ago, 650b was considered an obsolete size, when it was resurrected to convert road frames to fat tires. 650c is still out there, but availability is pretty limited. One of my lowracers is 650c/406

shelbyfv

Link

grolby

650C wheels have at times been referred to as “26 inch” and a tubular smaller than 700C would almost certainly be 650C so that’s my bet, but I would check very carefully. However - the Vittoria Juniores is definitely a 650C tubular, so seems unlikely to be anything else.

If we want to get technical (and I know we do ) I don’t think the usual ISO size system applies to tubulars. After all, the ISO system is based on bead set diameter, and tubeless tires don’t have beads. So while a tubular might be labeled as “700C,” it shouldn’t be labeled as “622,” the 700C bead set diameter for clinchers. It might be anyway, but it doesn’t really make sense. The tubulars in my basement, however (all made by Challenge at the moment) are labeled as 28”. Which is a common convention in Europe for 700C in general. But now that I mention it - I think it might also have been convention at one time to label a 650C tubular as 26”. But that might be some kind of fever dream or false memory.

79pmooney

A historical note - tubulars have been around for more than 120 years. In the past, all were hand made. Same with rims. Until the '70s, all performance bikes had them. England played around with a number of wheel sizes. There were both rim makers and tubular makers who would happily do runs of any size anyone was willing to pay for. A lot of different "standards" happened. So - there are wheels out there that are not to any standard known today or may will have been called a whatever and be close to but not the same as anything we think of now. So, having an old English wheel in hand does not mean you will ever find the tire that fits. Probably, yes, but for dead on certain? No.

Edit: And the other thought - its a Mavic rim. Contact them. They know what it is. And probably the equivalent clincher, tires, etc.