finding the right tube

[RetFor]

Hi, while I've been riding bikes for a long time, I haven't tried to do work on em myself before. I've gotten fed up with the lousy shops around here, though, so I want to try doing some stuff myself, starting with changing flats, which I get a lot. To help prevent flats, I'm going to stick in a mr tuffy liner while I'm at it.

I'm finding finding the right tube to be a little confusing, though. My tires say 700 x 35c (28 x 1 5/8 x 1 3/8) on them. (Well, the front one, anyway, the back one just says 700 x 37c.) From what I've seen doing some research, the tubes and liners are good for a range, which is why I don't see exactly that. Thats fine. But what I don't get is that the tubes with the range that fits my tires for the 700 x 35 designation doesnt seem to fit the 28 x 1 5/8 x 1 3/8 designation. One example of what I'm looking at is Sunlite Bicycle Tube, 700 x 35-40 (27 x 1-3/8) SCHRADER Valve. If it was just the width that was off a bit that wouldn't really bother me, but this appears to be an inch diamter difference.

So, what gives? Will these fit?

thanks

 

[dabac]

Tubes are air bladders, they'll stretch until stopped by the tire. Buying a little small will make mounting easier, but may make them more prone to flats as the material has to stretch more. Buying a little big will require more care at mounting.

Your issue is that the tube you're talking about is marked to be cross-compatible with two different sizing standards.
In the wonderful world of tire sizes the most common 28" has a bead seat diameter of 622 mm, while the less common 27-x-something" has a bead seat diameter of 630 mm. So it's not one inch difference, more like 1/3", which is nothing to worry about.

And just to keep you on your toes, three's a 28-x-something that is 635 mm ETRTO bead seat diameter.

If you can, stick with the ETRTO sizing, it's the least confusing one out there. You get bead seat diameter and approximate width in unambiguous millimeter values.

And just so that you know: 700C = 622 mm ETRTO

 

[RetFor]

so the tube i mentioned will work for my tires then?

(theyre marked with the ETRTO sizing as well, 37-622, but the tubes dont seem to be sized by that, so it doesnt help.)

btw, what exactly is the bead seat diameter? i cant seem to find a straight definition of what it is, just stuff talking about it.

thanks.

 

[alienator]

so the tube i mentioned will work for my tires then?   (theyre marked with the ETRTO  sizing as well, 37-622, but the tubes dont seem to be sized by that, so it doesnt help.) btw, what exactly is the bead seat diameter?  i cant seem to find a straight definition of what it is, just stuff talking about it. thanks.

Yup. They'll work for you.

 

[RetFor]

great, thanks.

 

[dabac]

Originally Posted by RetFor .

so the tube i mentioned will work for my tires then?

(theyre marked with the ETRTO sizing as well, 37-622, but the tubes dont seem to be sized by that, so it doesnt help.)

btw, what exactly is the bead seat diameter? i cant seem to find a straight definition of what it is, just stuff talking about it.

thanks.

Yes, the suggested tube will work with your tires.

Bead seat diameter:
-Look at an unmounted tire. You'll see that that where the edge of the tire sidewall makes contact with the rim, there's a thickened "lip". That "lip", or reinforced area is known as the "bead" in bikespeak. Probably in Car, and Motorcyclespeak too I suppose.
Now look at a bare rim. You'll see that the inside of the rim sidewall has a raised edge. To have a working wheel, the bead of the tire has to end up just inside that raised edge. That's the bead seat, and the bead seat diameter.