UPDATE: Big thank you to all those who gave me advice! It led me to believe that there was nothing really wrong with my new tire, rather with my method of putting the tire on. There was no need to return the tire and exchange it for a smaller one - I used a "trick" of putting only half of the tire on the rim, then inserting the inner tube, then putting the other half of the tire on, and it worked! Now all is good :)

My old tire has worn out after a couple of years of use, and I decided to replace it. Unfortunately, the exact same model of the old Kenda tire is no longer for sale. So, I went to the local bike shop and bought a Schwalbe Land Cruiser tire of exactly the same size (42-622). However, when I tried to put the new tire on, it felt far too loose on the wheel.

My question is, have I bought the correct tire for my bicycle? Should I still be able to fit the new tire on my wheel? I don't know how to explain this in proper terminology, but it seems like my two tires are still very different, despite having the same ETRTO code. Attached is the image of my old tire on the right, and the new one (which didn't fit) on the left.

Would be wonderful if someone could help me out here. Two tires, side by side

  • 2
    Some tires do fit very loosely on the rim despite being the correct nominal size. I've used tires that do not require any tool to install or remove from the rim, but once the tube is inflated they are held securely in place. This may be the tire being on the bigger side of its manufacturing tolerance and the rim being in the small side. My fear was that in case of a puncture the tire would slide off while rolling, but this was for an MTB used only on trails. I'd be wary of using such tire/rim combo for riding alongside motorized traffic. I suggest trying to return/exchange the tire.
    – Jahaziel
    Dec 14, 2021 at 15:21
  • I second what @Jahaziel said. With traditional clincher tires, it is possible that a tire will be loose enough to remove by hand. We would not tolerate this in a tubeless clincher system, but you don’t have that. Just to clarify to the OP, the “42” part is the tire’s width, and the “622” part is the rim type. This means the rim’s bead seat diameter, which is 622mm. The common names for this wheel size are 700c for road bikes, 29” for MTBs.
    – Weiwen Ng
    Dec 14, 2021 at 15:51

2 Answers 2


The ETRTO size is the correct thing to compare. Manufacturing has some tolerances, so there are small differences between tires that have same nominal size. If the tire is so loose that it doesn't stay on the rim, that should be a good reason to return the tire. The other "28 inch" tire would be 635mm, and it is so much larger that it is impossible to install on 622mm rim.

  • I'm not sure if it's an issue with the manufacturing differences. I feel like it's a problem with the type of the tire itself. As you can see in the old tire, the sidewalls "close in", but for the new one, the two sidewalls don't touch each other. Should that be an issue? Dec 14, 2021 at 15:02
  • 4
    The sidewalls coming together like your old one is a little unusual but not completely unknown. It's not much to do with the tyre size, and I've only seen it on old tyres.
    – Chris H
    Dec 14, 2021 at 15:06
  • 3
    Brief discussion of tolerances on the Terminology Index if anyone’s interested: bicycles.stackexchange.com/a/81703/38270
    – Weiwen Ng
    Dec 14, 2021 at 15:50

A new MTB tire may look like way and way too large until it is flat and just unfolded from the package. It actually is not. Do not get scary, try to put the tire the way it should be and you may discover it is fully ok at the end.

This is because the tire provides significant distance between the ground and the rim. Hence its outer diameter is way above the rim diameter, creating this illusion. The inner diameter is not seen until you fold the edges inside into the rim.

You only need to watch the rim diameter (28 inch, 27.5 inch and the like) and the tire width (and slightly different width may sometimes fit, see the chart on this question). Absolutely it does not need to be the same as has arrived with the bicycle, you can buy a different one that matches your riding conditions (winter, etc).

  • So, are you saying that the tire bead wires somehow become shorter when the tire is installed on the rim?
    – ojs
    Dec 15, 2021 at 8:52
  • When you put the tire on the table, and then the rim into it, the rim edge rests on the bottom of the tire and not on the rim bead. The tire appears way too large then.
    – nightrider
    Dec 15, 2021 at 9:29

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.