Tubs for 27inch wheels

[blutto]

Anyone still using tubs on 27" sprints and where do you get them if so.

 

[Jonny69]

Yes, got tubs on a couple of sets of wheels from 50s to 00s. I’m 99.999999999% certain that 27”, 28”, 29” and 700c tubs are all the same size but for some reason sellers (and for that matter manufacturers) seem to refer to them as all of those sizes. It’s very confusing.

 

[Glug]

I use tubulars but they're all 700C,
Sheldon Brown has

"Full-sized tubulars fit rims of the same diameter as 622 mm (700c) clinchers. This size is sometimes referred to as "28 inch" or "700". It is also, confusingly, sometimes referred to as "27 inch." The "27 inch" designation is inaccurate and obsolete, but you'll sometimes run into it in older printed material. "

From https://www.sheldonbrown.com/tire-sizing.html

But he also says there were 24" and 26" sizes.

So I'm guessing you need to check the size of your rims or exactly what make they are.

 

[blutto]

Yes, got tubs on a couple of sets of wheels from 50s to 00s. I’m 99.999999999% certain that 27”, 28”, 29” and 700c tubs are all the same size but for some reason sellers (and for that matter manufacturers) seem to refer to them as all of those sizes. It’s very confusing.

Hi thanks for the reply.
I have just the one set of wheels, Campag large flange hubs with Fiamme rims from the early 60s but they haven't had tubs on for about thirty years
and can't remember what size tubs i used to get
I'm trying to build my old 1947 Hobbs frame back up using all my 60s gear, in the back of my mind I think they were 27".
The diameter of the rims ( without tubs ) is 25" does that sound about right, if so will 700c be ok ?
Many thanks for your help, Colin.

 

[Glug]

25" is 635mm but it depends where you measured that.
700c is 622mm at the base of the rim - the bottom of the tyre groove.

I'm reasonably sure a Fiamme rim would be 700c.
Here's a table of polished silver tubular rims I made recently - they are all 700c

 

[ChromeChainstay]

25" is 635mm but it depends where you measured that.
700c is 622mm at the base of the rim - the bottom of the tyre groove.

I'm reasonably sure a Fiamme rim would be 700c.
Here's a table of polished silver tubular rims I made recently - they are all 700c

View attachment 901886

thanks

 

[bikeworkshop]

700c is a clincher size.

In Britain, sprints were called 27s, width given as 7/8" or 1"

Nowdays tub manufacturers (none British iirc) call them 700s, equivalent width as 22 or 25.

I don't think they called them 700s historically, hence the confusion.

There's no difference 27/700 in the tubular world, apart from geographical naming convention.

For clincher of course 27" is 630, whereas 700 is 622, 4mm smaller in tyre fit radius.