tube sizing - wtf?

justo

can anyone tell me the size protocol for tubes?

I want to buy some spare tubes and the box of my current tube says:

27/ 28 * 3/4 +1+1.1/16
700*18- 25c
18/25-622/630

What does all of this mean?

Is this a good replacement?
http://www.chainreactioncycles.com/Basket.aspx

thanks

cython

justo wrote: »

can anyone tell me the size protocol for tubes?

I want to buy some spare tubes and the box of my current tube says:

27/ 28 * 3/4 +1+1.1/16
700*18- 25c
18/25-622/630

What does all of this mean?

Is this a good replacement?
http://www.chainreactioncycles.com/Basket.aspx

thanks

First of all, your link there is to a basket, rather than to the product, so we can't see what you're referring to, only anything that we may have in our own baskets.

Next, I'm not sure what tube to recommend to you, but if you know what's written on the tyre, it might narrow it down a bit more?

justo

cython wrote: »

First of all, your link there is to a basket, rather than to the product, so we can't see what you're referring to, only anything that we may have in our own baskets.

Next, I'm not sure what tube to recommend to you, but if you know what's written on the tyre, it might narrow it down a bit more?

Correct link:
http://www.chainreactioncycles.com/Models.aspx?ModelID=44164

I can look at the tyre for more info. but really I want to know how to read the size information for future reference.

cython

justo wrote: »

Correct link:
http://www.chainreactioncycles.com/Models.aspx?ModelID=44164

I can look at the tyre for more info. but really I want to know how to read the size information for future reference.

That looks like it'd cover most or all of the ranges specified on your old tube alright. I can understand what you mean about being able to read it, but I generally buy the tube to fit the tyre, mainly because then I don't have to actually get to the point of removing the tube to figure out what type to get. Generally, as long as the tube is for the same size wheel, and it is suitable for the same bead width, which that one appears to be, it would be an adequate replacement.

27/ 28 * 3/4 +1+1.1/16

I think this is an imperial measurement for the tube size

700*18- 25c

Metric measurement. Bear in mind that most road tyres are 700c, and then 18-25 is the range of bead widths that it will cover

18/25-622/630

Another metric measurement, perhaps based on the wheel size, rather than the tyre size?

I'm open to correction on any of those, as I am guessing a bit from limited experience.

justo

cython wrote: »

That looks like it'd cover most or all of the ranges specified on your old tube alright. I can understand what you mean about being able to read it, but I generally buy the tube to fit the tyre, mainly because then I don't have to actually get to the point of removing the tube to figure out what type to get. Generally, as long as the tube is for the same size wheel, and it is suitable for the same bead width, which that one appears to be, it would be an adequate replacement.


I think this is an imperial measurement for the tube size

Metric measurement. Bear in mind that most road tyres are 700c, and then 18-25 is the range of bead widths that it will cover

Another metric measurement, perhaps based on the wheel size, rather than the tyre size?

I'm open to correction on any of those, as I am guessing a bit from limited experience.

Thanks - this is good info.

blorg

622 is the ISO/ETRTO standard and is the diameter of a road rim in mm. 700c is an old nominal measurement of the wheel including a tyre; obviously this varies according the the tyre size so it makes more sense to reference the rim diameter. This was quite a chunky tyre; virtually no road tyres are actually 700 any more.

Lumen

blorg wrote: »

622 is the ISO/ETRTO standard and is the diameter of a road rim in mm

It's the diameter of the bead seat. This may seem pedantic but it matters if you're measuring your rims.