Classic & Vintage - 27x1 = 700C?

That's what my LBS claims, at least over the phone. The 27x1 is on a Motobecane, vintage about 1980. When I called my LBS, the guy I talked to said "I think that's just a standard 700C road tire". I've looked over some Sheldon Brown info on the internet, and I can't imagine that a 700C will fit my rim. I said I'd bring both the wheel and old (dry rotted) tire in for comparison. Is it even worth a trip over there?

find a new lbs.

Someone at your LBS is clueless. No way will the tire fit. Call again and see if there's someone there that knows what they're talking about. If you get more of the same, you're better off going somewhere else.

No! they are different sizes. Move on to another bike shop.

I always understood them to be a few MM different in diameter though I've only tried to squeeze one 700C tire onto a 27x in a futile attempt.
Sheldon's chart on bead seat diameter seems to support this.
http://sheldonbrown.com/tyre-sizing.html
ISO Bead Seat Diameter Traditional Designations
630 mm 27 x anything
622 mm 700 C, 28 x (two fractions), 29 inch (28 x 1 1/2 F.13 Canada)

Unless it's on your way somewhere "I think that's just a standard 700C road tire" isn't very reassuring.

Run away, find a LBS with an old guy, or a kid who understands the old school.

27" and 700's are different animals alltogether.

I'd suggest giving him the 630mm size instead, but he might try to sell you a 27X1-1/4" Kenda instead.

Might be best to get a good 27X1" on eBay.

-Kurt

I'd suggest giving him the 630mm size instead, but he might try to sell you a 27X1-1/4" Kenda instead.

Might be best to get a good 27X1" on eBay.

-Kurt

Nah, just march into the shop, tell them to hand you the QBP catalog, and show them the tire you want. I've actually had to do that on a couple occasions (The kid at the counter had no idea there was such a thing a Jevelot's tire life compound or Frame saver). Sometimes the guys who've been at the shop know what's up, but the new help doesn't know all they should.

Tires, no. 700c tubes will work fine in 27" tires, though.....

LBS #2 (within walking distance of the first) knew right away what I meant when I called. Unfortunately, the closest they have is 27x1&1/8. How would these do?

Fine, an eighth inch wider isn't going to be an issue at all. You might even like it better.

Fine, an eighth inch wider isn't going to be an issue at all. You might even like it better.

I concur. Lots of us like 1-1/8" = 28mm width for riding on real roads with potholes and other imperfections. It is also a wonderful size for long distance riding, at about 10% lower inflation pressure than your 1" = 25mm tires.

Bear in mind, however, that true tire size can vary quite a bit from one manufacturer to another and even from one model to another. I have some 700Cx28 Continentals that should probably have been labeled 26 or even 25mm.

Nah, just march into the shop, tell them to hand you the QBP catalog, and show them the tire you want.

That's the norm over here :rolleyes: .

Most of my LBS discussions run as follows (I get a kick out of it too):

"Howdy. I need to get a (insert part name here) - got any on hand?"
"A what?"
"A (part name)"
"What's that?"
"It's for (whatever part does)"
*Blank stare from shop fellow
"Can I thumb through your J&B catalog?"
"Sure"
"All right - here it is"

and from that point, it's either:

"Oh, we have that," and he'll pull it out of the back
or
"Nope, don't got it" - and if it's a shop I know well, I'll dive into the back room and pull the part out five minutes later.

:D

-Kurt

It would take the same tube, that's about the only similarity though. 4 mm less radius for 700c

I always understood them to be a few MM different in diameter though I've only tried to squeeze one 700C tire onto a 27x in a futile attempt.
Sheldon's chart on bead seat diameter seems to support this.
http://sheldonbrown.com/tyre-sizing.html
ISO Bead Seat Diameter Traditional Designations
630 mm 27 x anything
622 mm 700 C, 28 x (two fractions), 29 inch (28 x 1 1/2 F.13 Canada)

Unless it's on your way somewhere "I think that's just a standard 700C road tire" isn't very reassuring.


The difference is 4mm of radius.

The continentals usually come marked 27"X1" when they are clearly 700c, though.

The continentals usually come marked 27"X1" when they are clearly 700c, though.

Come again?

The continentals usually come marked 27"X1" when they are clearly 700c, though.

I've seen that before - usually on the 1000s or one of the other lower end models, right? As if there weren't enough confusion about sizing already. Oh well, keeps us on our toes, eh?

-Kurt

The continentals usually come marked 27"X1" when they are clearly 700c, though.

I don't buy Continental tires because they have issues measuring the proper size of their product. It's nigh-on impossible to mount their road tires without using something to get extra leverage. Sacrificing tubes to mount a tire is just unacceptable to me.

I don't buy Continental tires because they have issues measuring the proper size of their product. It's nigh-on impossible to mount their road tires without using something to get extra leverage. ...

Been there ... done that. Try putting Conti. Ultra-2000s on Campagnolo Omega rims -- this is the only combination for which I have needed tire levers to mount both beads. I don't leave home on the Bianchi without three steel tire levers.

I think I'll try Vittorias next time.

How would a 27x1&1/8 tire go on a 27x1 rim? Wouldn't it be a little fat?

It really depends on the actual rim dimensions. I have a set of Weinman rims that are stamped 27x1 1/4 that are only 15mm between the beads. My Araya rims with the same markings are 19mm. Sheldon has a compatability chart: http://www.sheldonbrown.com/tire-sizing.html#width To answer your question, if the rim is between 15 and 19mm, 27x1 1/8 should fit.

I ride with 27x1.25 and I actually prefer it to the 27x1 tires I had before. Especially since I use my bike to commute and my streets are less than perfect. Had no problem with my old Araya 27x1 rims. :)

Araya 27x1 rims are the ones on this bike as well. You are able to mount and ride 27x1.25's on them? Perhaps there is hope after all! My main concern is that I might be able to buy 27x1 or 27x1.125 tires today, but what about 5 years from now? The 27x1.25's will probably be available for years to come, however.

For the most part,you can fit wider tires on narrow rims, but not narrower tires on wider rims.

Yes. There was no problem putting the 1.25" wide tires on the 1" wide rims. The tires I use are Continental GatorSkin+K. Satisfied so far.