My bicycle is about 25 years old and for the past decade has been sitting out on my balcony (dry, but outside temperature, which around here means from -15°C to +40°C or so). Lately I've been thinking about reviving it. Once I take it out for a spin I'll know what else I need to fix, but for now the obvious thing is the tires, which don't hold air at all anymore.

I wrote down the size numbers I found on them - 26x2.125 - but I don't know if they are tubed or tubeless. I suspect they are tubed, but I won't be able to tell until I dig the thing out. And it would be nice if I had the replacements ready by then.

So, my question - If I go into my LBS and buy the first tubed tires that I see with matching numbers on them - what's the risk they won't fit?

  • If the bike's been outside for a decade, you will need new brake pads too. They go hard and have poor effectiveness as they age and harden. Good luck riding again !
    – Criggie
    Apr 13, 2020 at 20:44
  • Bike tubes are not as fussy, sizing wise, as tires. Pretty much any 26-inch tube that claims to be maybe 1.75 or wider should work, at least temporarily (though the closer you come to 2.125 the better). But note that a ten-year-old tire has likely gotten brittle and is apt to flake apart as you dismount and remount it. Apr 13, 2020 at 20:46
  • 1
    @Criggie - Good point! The brake pads were crap and stone hard even when I was still riding the bike, that much I remember. I'll pick those up too.
    – Vilx-
    Apr 14, 2020 at 0:23

1 Answer 1


If it's 25 years old, it's a tubed tire. 26x2.125 is a very standard MTB tire from that era. If you get any MTB 26" tire in the 2.2 to 1.5 in range that should work just fine on your bike.

For any tire made in the last 20 years there should be an ETRTO number on it as well, this is a number like 50-559. Its' designed tire width and rim diameter. So 26 x 2.125 would be 26 inch ( or 559mm ) rim and 2.125 inch width ( or ~55mm width).

I would put some money in your budget for new tubes as well.

For more on tire sizes check out Sheldon Browns Tire Sizing Guide

  • 1
    Errmm, with "tubed tires" I meant both the tires and the tubes. :)
    – Vilx-
    Apr 13, 2020 at 19:28

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