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I cannot put a replacement tire on my rear wheel, whatever I do, have spent half a day on this. It just should not be so extremely difficult, I have tools and it is not the first tire I am replacing in my life. It looks as if the tire is just too small, but it has been bought up to specs. The bicycle has 27.5 inch wheels, 2.35 inch diameter tires. This is printed on the front tire that is original, and I bought another with exactly the same numbers. Once I needed to replace a tube on the front wheel and had absolutely no problem in removing the front tire and putting it back.

The clue may be that recently I had the rear wheel replaced. It visually still looks very close to 27.5 inch but could it be that they managed to put a slightly different size for me? The size is not printed on the wheel. What is the "27.5+" tire size I see in the shop? Maybe this is my new size now? Or should I try 29 inch tire?

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    What exactly is printed on those tyres and rims?
    – Vladimir F Героям слава
    Oct 2, 2021 at 19:55
  • It's unlikely you've got a different wheel size, but just to be sure, what size is printed on the old tire you're replacing, and what's on the new one?
    – Adam Rice
    Oct 2, 2021 at 20:13
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    You need to put all identifying information in your post. Post pictures of the tires label/packaging, the runs label, etc. Otherwise we can only speculate and back and forth conversation doesn't work here.
    – whatsisname
    Oct 2, 2021 at 20:52
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    Have you ever changed a tyre ? Trying to figure if this is a technique problem or a physical problem
    – Criggie ♦
    Oct 2, 2021 at 21:52
  • Can you measure the rim if it doesn’t have any markings? Outside diameter (should be easy to measure accurately) and an estimate of the bead seat diameter would be helpful.
    – Michael
    Oct 3, 2021 at 8:15

4 Answers 4

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Put the tyre on as much as you can (ie. bead in the rim all the way round as far around as possibly) hopefully leaving you with a small section that seems too small.

Now put the wheel on your feet, with the section of tyre that seems too small facing away from you and bend the tyre over the top, towards you, with your hands/fingers gripped over the top and thumbs on the back of the wheel. Now clench your fingers and grip/pull/bend the tyre towards you and onto the rim, pushing with your thumbs on the back of the rim. Should stretch it over.

I don't know why tyres are so hard to get on one time and seem to slip on another time. I think the position of the bead in the rim can make a big difference.

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    This was indeed efficient to remove the tire, exposing the edge so that I would put a lifter there.
    – nightrider
    Oct 9, 2021 at 9:52
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    Glad I could help. Have been there; it’s rather hair pulling when it won’t go back on or come back off, when you fore well know it came off/went on that exact rim, before, with ease
    – CharakaSamawry
    Oct 11, 2021 at 0:15
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There are a few things I've found helpful when dealing with stubborn tires:

  1. Make sure ALL of the air is out of the inner tube.

  2. Squeeze the tire beads together towards the center of the rim, opposite of the part that won't go on. The center channel is deeper, so this will give some room to pull the tire away from the rim slightly. This may be enough to let to last bit slip over an on.

  3. A bead jack works for some tires, although the Koolstop one I have doesn't handle wide tires like yours. These tools work by giving much more leverage to lift the tire bead up over the rim.

  4. As a last resort, lubricating the tire bead and rim with some soapy water can help it slide over.

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  • Point 4 can be double-edged, sometimes having it slippery means it is harder to get to the tipping point, as you're working one end of the segment, the other slides away.
    – Criggie ♦
    Oct 3, 2021 at 3:12
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    5. Warm tyres help - so let your new tyre warm up inside overnight or in the sunlight.
    – Criggie ♦
    Oct 3, 2021 at 3:12
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    @Criggie are you sure warming is helpful? With steel beads maybe, but for foldable tyres this doesn't make sense. Kevlar has basically no thermal expansion (Goodfellow actually lists its thermal expansion coefficient as negative, i.e. it contracts – which is what rubber also does under heat).
    – leftaroundabout
    Oct 3, 2021 at 11:48
  • @leftaroundabout Huh I was unaware of that - but the warm tyre was more about pliability than expansion. That point where the bead is pulled against the rim in two places just as you're levering it past the hard point, having a stiff tyre then would make it more difficullt.
    – Criggie ♦
    Oct 3, 2021 at 12:36
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    @Criggie That is true. Not to mention the stiff clammy hands, which definitely don't make fixing tyres in the cold any easier.
    – leftaroundabout
    Oct 3, 2021 at 14:45
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A problem occasionally seen with some tire/rim combinations is that the rim has a very narrow trough through the center and unless the rim bead is nestled deeply into that trough the last few inches of bead cannot be stretched over the edge of the rim.

This scenario often takes careful planning.

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When only the last 20 cm section of the tire remains on the "wrong" outer side of the rim (and on one side only), pushing one end of this section with the lifter into the right position results another end slipping back into wrong one. This looks like a rather pointless activity but it is not so: the tire somehow settles better as the pushed section travels around the rim, and finally the section start shortening till it becomes possible to end with it.

I my case I needed to use the two heavy duty metal lifters one behind another. The commonly sold plastic lifters I tried before were just bending themselves. I also tried the mounting pliers like this but while the tool looks solid and seriously built, there was no any use out of it in my case. Maybe it is for different type of tires or needs skills to be useful.

Anyway, after making half a revolution around the rim, the tire moved better into its final position and the gap started to shorten, till I was able to close it.

The method described by @CharakaSamawry was efficient when removing the old tire, and was almost working when putting the tire back on the rim, but the power required was more than my fingers can handle. It may work better for some mountain climber.

It is clearly a rogue rim and not a rogue tire, because all three tires I have are very difficult to put on and off. The rim was replaced in the workshop while replacing the freewheel. I still do not understand, is it just wrongly forged (slightly too large?) or meant for some different tire type. I include the photo of the marking that is printed on it:

enter image description here

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