My tires are 622 x 38C, and on the rim it says 622 x 21C (m̶i̶n̶i̶m̶u̶m̶ ̶t̶i̶r̶e̶ ̶w̶i̶d̶t̶h̶ ̶t̶h̶e̶ ̶r̶i̶m̶ ̶s̶u̶p̶p̶o̶r̶t̶s̶,̶ ̶I̶ ̶b̶e̶l̶i̶e̶v̶e̶ rim width). These tires cost around 18 dollars each.

I've spent some time on:

  • making sure I haven't pinched the tube and there is no foreign object between the tire and the rim;
  • deflating, adjusting the bead, trying to straighten the tire, reinflating;

The rim is true, the bead seems fine, yet the tire has a noticeable wobble (~2mm I would say):

This is how the bead looks:

These are the original components of a 170USD bicycle I bought from Decathlon a month ago. They have bicycle mechanics and a repair shop; but I guess they don't spend a lot of time fine tuning the bicycles before selling, especially the cheaper ones.

The front tire (which I haven't touched yet) wobbles a bit more; the rim is also 1-2mm out of true.

Will this tire wobble wear down the bearings faster, or other components? Or is this amount considered normal, and won't do any harm? Is this as true as you can get on such a cheap bicycle? Should I spend more time trying to adjust or leave it as it is?

  • 1
    In the first shot, is the tire inflated or not? The fit cannot be expected to "hold" well unless the tire is inflated. Beyond that, the wobble I see is not ideal, but not particularly worrisome. – Daniel R Hicks Apr 30 at 20:04
  • It was partially inflated, not to a rideable pressure. – Robert Lee Apr 30 at 20:48
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    The tire is likely “true” but the tire bead is not properly seated in the rim channel. – Rider_X May 2 at 19:01
  • From the ease in which you could squeeze the tire in the 2nd video it is very under-inflated (although the bead - on that side at least - appears to be fairly well seated). I would expect any tire to be 'out of true' in that condition. Try inflating to riding pressure and repeat your test. – Penguino Aug 7 at 23:24
  • @Penguino Thank you for your suggestion. I had done that, but it didn't seem to help for the moment. Then, after riding the bike for a few dozen km, the wobble was diminished; not completely, but to a large extent. I rode ~1000km since then and didn't have any problems. There's still a slight wobble, but I don't mind it. – Robert Lee Aug 7 at 23:48
up vote 9 down vote accepted

I'll answer all your questions in order.

1) "Will this tire wobble wear down the bearings faster, or other components?" -Nope, this wobble will do pretty much nothing to the rim. If anything, you will feel the slightest of 'floating' (the only way I can describe it, the bulge ever-so-slightly lifting the bike when you go over it.)

2) "is this amount considered normal, and won't do any harm?" -Any tyre wobble is not classed as normal, though it will not do any harm to you, the bicycle or your bike's performance.

3) "Is this as true as you can get on such a cheap bicycle?" - The bicycle has nothing to do with the tyre. If the bike was £120, you can still get £80 Continentals. The tyre's quality, however, is quite a big factor. If you bought them for £12 a piece, there's a high chance that there may be minor defects.

4) "Should I spend more time trying to adjust or leave it as it is?" -Leave it. If anything, you risk doing more damage to the tyre/rim, constantly playing with it.

Ride around on this tyre for a couple days. In my experience with cheaper tyres, they'll settle down. It's usually due to storage/transit. Re-inflating usually gets rid of any deformation, though not always. Riding it for a while will eventually get it to even out.

If the tyre is damaged, you'll usually notice a very major bulge. If you take an innertube and inflate it, looking at the valve, you'll notice it has a weird shape around where the valve is. It'll look somewhat like that, but on the tyre.

  • 2
    Impressive nitpicking on item 3 :) – ojs Apr 30 at 20:12
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    ;) Can't be too broad with answers, I just like to make sure they know what they're buying and what they've bought. Also, this is mainly to help others that may do a quick touch-and-go on this page to look for a quick answer. – yollooool Apr 30 at 20:15
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    Take out the wheel Deflate the tyre, squeeze it between your fingers away from the rim all around. Inflate sightly then bounce the wheel wheel on the floor. Inflate slightly above the indicated maximum before adjusting to the correct pressure. Check the seating. Repeat if necessary. This will deal with recalcitrant tyres for most of the time. At least in my experience. – Carel May 1 at 11:44

It looks to me that your tire is not properly centered on the rim. Probably neither the rim nor the tire are faulty, but they require more effort to center the tire.

The first thing you should check is whether the rim tape is well-centered. One of the main reasons why a tire cannot center on the rim is that the rim tape has creeped up at some points towards one side of the rim.

enter image description here

When the rim tape is centered, you can put the tire and inner tube back on. Center the tire roughly with your hands and check that the inner tube is nowhere squeezed between tire and rim. Pump the inner tube to the maximum pressure indicated on the outside of the tire. You will probably hear some plops. At the maximum pressure the circular rim line on the tire should be at the same distance to the rim everywhere. If so, the problem if solved. Now reduce the inflation pressure to a value more comfortable for riding.

If it is not, there is a final trick. Release the pressure and wet both the outside walls of the tire and the rim hooks with a solution of a detergent using a cloth. A few drops of dish washing liquid in about 100 ml of water is good enough. Apply it generously to all surfaces without splashing it around. Now again pump to the maximum pressure. The soap should facilitate the tire beads to slide into the hooks of the rim.

See also "What can be done if the tyre cannot be centered?" on https://www.schwalbe.com/en-GB/montage.html

PM. For a 622x21C rim, the 21C stands for the rim width, not the minimum tire width. According to Schwalbe's "Which tyre fits which rim?" the minimum tire width for a 21C rim is 35 mm. See https://www.schwalbe.com/en-GB/reifenmasse.html

  • Thank you! I edited my question with the correct parenthesis on what 622x21C on the rim means. – Robert Lee May 2 at 12:56
  • Wouldn't the soapy water remain trapped and cause rust on the rim or the spoke nipples? – Robert Lee May 2 at 17:03
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    @RobertLisaru most rims now are aluminum, which does not rust. The trapped film of water will also eventually dry. In all honesty this answer does a bet job of answering your original question than the answer you selected. – Rider_X May 2 at 18:58
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    For those doing google searches “centering the tire” is often referred to as “seating the bead” as the tire bead has not properly seated itself in the rim channel. – Rider_X May 2 at 19:00
  • @Rider_X Thanks! I'll try using soapy water and inflate to max pressure as soon as I get myself a pump with pressure indicator. If it works, I will select this as the answer. – Robert Lee May 9 at 6:35

Mounting tires:

Check the rim tape/strip. Check the rim bead seat area.

Put a bit of air in the tube before attempting to mount the tire.

Put the first half of the tire on the rim. Put the tube into the tire. Start with putting the valve into the rim and stuff the tube into the tire. If needed let some air out ( not too much, you want it to have a basic round shape. ). This will keep it from getting pinched between the tire and the rim.

Starting away from the valve area, start pushing ( by hand only, no tools ) the second bead of the tire over onto the rim. the last ( and hardest, resist the urge to use tools, even plastic tire tools can hole the tube ).

Now you will have the valve area to push on. Do that, yes it will be a bit hard on your hands. Keep the valve area as the last to go on. Once the tire is on all the way, push the valve up into the tire as much as you can without loosing it. This will un-pinch the tube there, if it is pinched. If it will pinch, the last place you push over is likely to be where.

  • You're totally correct, if the question was how to fit a tyre. But OP's question is specifically about getting a budget tyre to run true, and not how to fit it. Welcome to the site - do have a browse of the tour for more info on how it works. – Criggie Aug 10 at 21:59

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