3

I'm an amateur cyclist trying to change worn out tires for the first time. I ordered some new tires from Amazon and got them in folded form.

The tires are flat like a belt and just won't go on the wheel. I bend them from the edges but they go back to being a flat belt like shape. Is there some special procedure I need to do to get them in shape or are these faulty?

enter image description here enter image description here

  • To clarify are you wanting to know how to mount folding tires on a wheel? Place one bead on the wheel, lightly inflate the tube and fit into the tire (this will provide shape) then starting in one place work the other bead into place with your thumbs. – Rider_X Mar 25 '18 at 14:54
  • Yes. What's this called? A youtube video will be helpful. But search engines are failing me. As a flat tire means a punctured one. – Kshitiz Sharma Mar 25 '18 at 15:01
  • How about searching “changing bicycle tire”? youtu.be/eqR6nlZNeU8 – Rider_X Mar 25 '18 at 15:11
  • 3
    We can tell you're an amateur -- if you were a pro, your mechanic would be fitting the new tyre for you. ;-) – David Richerby Mar 25 '18 at 15:52
  • 1
    Don't let people tell you it's all in your head. A "folding" tire (not simply a Kevlar bead tire) is shipped flat, and the cross-sectional shape of the tire is distorted. It takes a fair amount of monkeying to get it to fit. – Daniel R Hicks Mar 25 '18 at 22:26
2

The problem is that, if you force the tire into a circular shape, the center of the tread is only maybe 3 cm "taller" than the beads. This makes it hard to fit the tire onto the rim, with the tube inside. Once the tire has been fit and tube inflated the tread "stretches" to a more normal shape, but getting that initial fit is a challenge.

1

The procedure is mounting the tires on rims and inflating them. When mounting the first bead of the tire, it helps to keep the part already on rim pulled tight so that it does not fall off the rim.

0

The diameter of the tire bead does not change even though the tire has assumed a flattened out shape due to being stored that way. The bead diameter should be slightly smaller than the diameter of the rim flanges, so it you get one bead on the rim it should stay there.

the Park Tool Company YouTube video on fixing tires may help you. If you place the inner tube in the tire and inflate it a little before fitting the tire on the rim, that should help push the tire into its proper shape.

  • 1
    Has nothing to do with the bead diameter. A new folder has a TREAD diameter that is much smaller than the tread diameter of a standard tire. This makes it hard to fit. I'm sure there are tricks of the trade that bike mechanics know for this, but for the average Joe it's about 30 minutes of profanities. – Daniel R Hicks Mar 25 '18 at 22:24
  • The bead diameter must be less than the rim flange diameter, otherwise the tire would just blow off the rim. – Argenti Apparatus Mar 25 '18 at 22:36
  • If the tire is speced for the rim, and the manufacturer is not incredibly incompetent, the bead diameter is less than the rim diameter. That's not the problem. – Daniel R Hicks Mar 26 '18 at 12:11

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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