What tube do I need to buy for a Cube SL Road Race Bike?

Question

Sorry for such a newbie question but I truly am in need of some guidance to make sure I buy the right thing.

I recently bought a Cube SL Road Race which I've been out on a few times, covering about 60 miles. When I came to use the bike today I found the front tyre had gone flat so I find myself needing to get hold of a replacement tube.

The tyre is a Schwalbe Kojak with markings which read 35-622 28 x 1.35, 700 x 350. 4.0 - 6.5 BAP, 55 - 95 PSI. The wheel is a Fulcrum Racing Seventy Seven Db

Can anyone help me to understand what replacement tube I need to buy? I'd also appreciate any guidance which might help prevent punctures in the future.

Many Thanks!

Answer 1

When you buy your new tube, consider also getting a puncture repair kit as well at the same time. Then you don't have to throw away the current tube ($) and you can repair punctures away from home too.

To understand the numbers, the most meaningful set is 35-622. This code is saying that the tyre is 35mm wide and has an inner diameter of 622mm.

The tube will stretch to fit a range of tyre sizes. See the image below of a bike tube packet, there is a list of numbers showing all the different tyres it is suitable for, I've highlighted the two columns of information. Looking down the list on the left, we can see 32-622 and 37-622. We're after 35-622 which fits between these, so this tube will fit in our tyre nicely.

The other important aspect is the valve type, Presta or Schrader. We have explainers here, Presta and Schrader and I see from your photo you have a Presta valve (also known as a Sclaverand Valve). It matters because the rim will have a hole that suits one type - road tyres are normally the narrower Presta type.

To understand the other sets of numbers:

• 28 x 1.35 and 700x35 C are old ways of saying the tyre size but mean just the same thing. The first is in inches and the second is in French. You can state these and be understood, they are equivalent.
• 4.0 - 6.5 BAP, 55-95 psi are two different ways of stating the pressure range the tyre should be inflated within, using two different sets of units.

Answer 2

You need any traditional road or cyclocross or gravel or hybrid bike tube with (that means 700 mm outer diameter 622 mm rim diameter, that is the ubiquitous road wheel size) or an MTB (trekking, hybrid,...) tube for 28 inch diameter tyres (also called 29 inch, it is the same as the former, just in inches) that allows for 35 mm resp. 1.35 inch tyres (the width). The tubes are made for a range of widths. It is better if the rubes lower range is closer to those 35 mm, but not essential.

The two types are the same thing, they are just sometimes sold in mm and sometimes in inches.

Always make sure you are buying the correct valve type! (FV (also SV) or AV, also called Presta or Schräder (also Autoventil) ). Your valve is Presta, also marked as FV or SV.

You can also use this handy site https://www.schwalbe.com/en/schlaeuche Enter ETRTO 35-622 or Inch 28 x 1.35 or French 700x35C. Those are equivalent. These markings can be found on the packagings of tubes of various manufacturers and any bike shop salesperson will know what you need as well.

Puncture resistance is more about the tyre than about the tube and there are many tips in different questions on this site. Be sure to search for puncture protection here! With tubes punctures are inevitable from time to time. Always carry a spare tube and a repair kit and be prepared to use them.

I had these two packagings at home. Both would work for you and you can note how different the markings can be.

This is the reason I started my answer with "you need a typical road 700mm tube for 35mm width. That is what thepackaging on the laft marks with the biggest letters. You can call it "old" but it is what most road bike people use (MTB uses inches). The ERTO numbers are the technical exact standard numbers, you may calk them "the most meaningful", but may be not be present on the packaging at all or only as the last number. I suggest to not look for that too much. Your eyes should look for big 700 or big 28 in the shop. Big 622 is very unlikely.