Bicycle Mechanics - bicycle tube measurements

hi everyone...im new to riding and need a little help understanding bicycle tube measurements because i bought a bike that uses rare tubes that i cant seem to find anywhere.

the tube it uses (according to an online source) is 700c x 35-43 tube with a 48mm Presta valve


however, the bike i have has schrader valves....i know 700c is the circumference; however, i dont know what the 35-43 measurement is.. and i do believe the 48mm is the valve length? but im not sure about this either.

Ok:

700c is the nominal diameter of the rim. Actually, I think it's 622mm. In general, tubes for 700c rims and 27" rims are interchangeable. Remember this, because if you need shrader valves, they are more common among 27" wheels than among 700c rims.

35-43 is the recommended tire width for the tube. It is in mm. So, that tube is for either a 700c or 27" wheel with a tire that is from 35mm to 43mm in width.

48mm is the length of the valve. 48mm is a common short presta valve length. Nothing special.

So, look at the width of the tires that you are using and get a tube for that diameter tire and with the proper valve. They will be available in either shrader or presta in that size. Note that 35mm is about 1 1/2" and 43mm is about 1 11/16" so a tube labeled as 27" 1 1/2 - 1 3/4 will be about the same size tube. Probably interchangeable.

Tubes stretch well so you can likely use a tube labeled for a smaller tire without a problem. 700c 32-35, for example, would be ok. Some people like to use tubes for the next larger size because the rubber will probably end up being a little thicker when inflated -- thus, the thinking goes, more durable. Be careful if you use tubes labeled for tires bigger than you have, because all that flabby rubber tends to get caught between the tire bead and the rim when you mount your tires. We fat people can relate.

Tubes in various sizes are proably more available with presta valves than with shrader. And even though shrader (auto type) valves might seem more understandable at first, I think you will end up liking presta more. So, you can get some little bushings that fit in the shrader holes and adapt them to tubes with presta valves. A great invention, in my opinion.

Nothing rare about that tube size. 27" tubes will interchange with 700c, and those tubes with Scharder valves are everywhere. Remember, scharder valves are the typical automotive valves, presta valves have the small nut on the top.

Ok:

700c is the nominal diameter of the rim. Actually, I think it's 622mm. In general, tubes for 700c rims and 27" rims are interchangeable. Remember this, because if you need shrader valves, they are more common among 27" wheels than among 700c rims.

35-43 is the recommended tire width for the tube. It is in mm. So, that tube is for either a 700c or 27" wheel with a tire that is from 35mm to 43mm in width.

48mm is the length of the valve. 48mm is a common short presta valve length. Nothing special.

So, look at the width of the tires that you are using and get a tube for that diameter tire and with the proper valve. They will be available in either shrader or presta in that size. Note that 35mm is about 1 1/2" and 43mm is about 1 11/16" so a tube labeled as 27" 1 1/2 - 1 3/4 will be about the same size tube. Probably interchangeable.

Tubes stretch well so you can likely use a tube labeled for a smaller tire without a problem. 700c 32-35, for example, would be ok. Some people like to use tubes for the next larger size because the rubber will probably end up being a little thicker when inflated -- thus, the thinking goes, more durable. Be careful if you use tubes labeled for tires bigger than you have, because all that flabby rubber tends to get caught between the tire bead and the rim when you mount your tires. We fat people can relate.

Tubes in various sizes are proably more available with presta valves than with shrader. And even though shrader (auto type) valves might seem more understandable at first, I think you will end up liking presta more. So, you can get some little bushings that fit in the shrader holes and adapt them to tubes with presta valves. A great invention, in my opinion.

hey thanks for all that info...will my bicycle pump work with presta valves? the presta valves look smaller than schrader valves....also, what is the bushing component? what does it do?

hey thanks for all that info...will my bicycle pump work with presta valves? the presta valves look smaller than schrader valves....also, what is the bushing component? what does it do?

Not knowing what pump you have, there are adapters if you have a scharder only air chuck. Presta valves are smaller and have a short procedure to follow to inflate: unscrew the top of the valve, then burp the valve by pressing the top in, inflate, then screw the top back down.

Some pumps have a reversable rubber insert in the pump head to work on presta or shraeder. I beleive the bushing component is the stem nut. I don't use the stem nut but many do. The reasons to use them and the reasons not to use them have been hotly debated but hopefully we won't go there on this topic. Tubes your size should be available at most bike shops.

The bushing:

Shrader valves require a larger diameter hole than do presta valves. Therefore, presta valves are kind of small compared to the hole in the rim designed for a shrader. You can buy little bushings the outside diameter of which is the diameter of a shrader and the inside diameter is that of a presta. Put one of these in a shrader hole and viola, you've got yourself a presta hole. One version of this is called "presta saver" and is like $2 to $3. Seems like a lot for what it is. Probably, the best thing to do is to buy shrader valve tubes, if you've got rims with those big holes in them.