Long story short my tubes kept popping and I resolved to replace the tires, tubes and tape. I got busy with other stuff. That was in September.
I did some reading about puncture-resistant tires. Marathons look good and Green Marathons look affordable. Trouble is, my rim stamp sizing doesn't match the available sizings on the Schwalbe store. So I started reading about sizing.
What a mess. It's overwhelming. It wasn't my first choice but I decided to use ChatGPT to tease apart the issue. Sorry if that's cringe.
https://chatgpt.com/share/6a31d15d-f25c-83ea-8288-462a4d87be4e
I didn't get my questions answered per se, but I understand that width at least is a somewhat flexible parameter. One possibility M. GPT did not entertain is that I am extremely unlucky and my rim is actually mis-stamped. Three last details: I removed my inner tubes, which are labeled 26 x 2.125; Using a tape measure, I approximated the diameter of my wheels at 22.5 inches at the outside of the rim; My local bike shop has disappointed me twice and satisfied me zero times, however there is also a free community service center for my broke ass at which I have had limited success.
So strictly speaking, my questions are as follows:
What size Marathon Green tire will fit my wheel? What size inner tube should I buy? Pinch flats may have been an issue previously. What size rim tape should I buy?
More generally my confusion lies in the following:
Why does my stamp appear to indicate a sizing that isn't real? Is this an obscure sizing? Is it mis-stamped? Is there something I'm missing? Do I need to buy a new wheel? What new wheel would work? Considering that I also need to remove a lock for which I have no key, and that my break lines are shot, and that I need a fender and chain guard, should I be doing any of this? Should I just buy a new bike? Should I chop this bike into tiny pieces? Why haven't I chopped this bike into tiny pieces? Why don't I own a car? Why am I such a cheapskate?
Any help is appreciated. Commentary is welcome.
by AspenRiot
12 Comments
What are the tires labeled? Any tire around 26×2.1 should work and tubes are generally sold in ranges like 26×1.75-2.25 so you want to find one thats within range of your tire. And you want to make sure they have a Schrader valve
Looks like the marathon green only comes in 26×2.0 which would work fine on your rims
Key facts:
You have a “26 inch” rim at a width of “kinda wide”.
You have a frame with clearance for pretty wide tires, but not huge tires.
You have a clincher rim (I assume).
You will need to buy a tire with the following properties:
– tire 26″ diameter (sometimes called “559”)
– Width between 1.5 to 2.5,
– tread pattern appropriate to your terrain and preferences.
You will need a tube with
– tube diameter 26″ and
– tube width of “in the same territory to the tire”
To answer your question of “which cicled Marathon” the answer is “any of them.” Wider is better on dirt and for heavy riders.
But let me propose a stylish alternative: Schwalbe Big Bens in 26×2.15
A bike rim fits several tire sizes. I think that should help you understand.
The diameter is fixed, so when people talk about tire sizes, they talk about the width.
There’s a norm that set which tire sizes will work safely on which rims. This usually provides a floor of a tire size range for any given bike. The ceiling is the clearance allowed by the frame.
Having said this, a xxx-xx (or xx-xxx) number written on a rim will in 95% of cases denote the inner rim width and the outer diameter of the rim.
The same numbering on a tire denotes the inner diameter and the tire width. What you have is a rim with a 599mm outer diameter and a 22mm inner width.
Having said all this, we can’t forget that standards change over time and when talking about bike tires, that stuff simply falls out of favor.
A 599 tire size is basically completely dead. You may notice the 26″ written on the rim and the tire but here’s the thing. Nobody really set what is actually 26 inches long when everything about this clusterguck came to be, so everything from 559mm to 597mm is all called 26 inch.
A 26 x 1,75 inch tire is technically a 45-559 tire but it may very well be that this won’t fit. You just have to try. That’s how it is when vintage stuff uses the same systems as modern stuff but also not quite really but somehow still does.
1. replace the rim tape with velox cloth rim tape
2. any 26″ tube with a width range of 1.8 – 2.2 and schraeder valves will work. it stretches. don’t overthink this.
3. as u/grantrules has said, 26×2.0 will be sufficient for this
4. cut the bike lock off or contact kryptonite for a spare key
5. your brakes look like they need adjustment.
6. sure. replace your brake cables and housing. it won’t hurt and it will probably fit.
7. why do you need a chain guard
8. yeah you can add a fender
Tire sizing is stupid.
You have 26 inch wheels. Nothing will measure exactly 26 inches. Go to any bike shop and buy 26 inch tires and they will fit.
559 etrto is the standardized rim measurement. 559 and 26 are one in the same.
Read this if your bored and really want to understand:
https://www.sheldonbrown.com/tire-sizing.html
…Stop using ChatGPT.
Are those fucking aero canti brakes?!
If the tubes keep popping you should check the inside of your tire very thoroughly for anything that might be stuck in it, and your rim tape to make sure it doesn’t have holes in it.
To answer your question about tire sizes, anything in the range of 26 x 1.5 to 26 x 2.0 is most likely fine, so what you circled, just figure out how wide you want em. I’m not a tire size expert but I don’t think 26×1.75 is a rare size at all. In fact, one of the options you circled is 26×1.75. There’s some fuckery with old fashioned wheel sizes I’m not fully informed of so you might just need to give what you pick out a shot. Tires are flexible so they’ll probably fit.
You could probably keep using your existing tires if you figure out why your tubes keep popping. Make sure your tubes are compatible and not too small or too deflated. Too deflated = pinch flats. You can tell if they’re pinch flats because the holes often look like snakebites.
I don’t think your rims are mislabeled.
You can measure the inside of your rims yourself for rim tape size, or you can take it to a shop and have them look at it and pick one out for you.
You don’t need new wheels.
Only get a fender and a chain guard if you want them.
Lock looks easy to remove with bolt cutters, angle grinder, hacksaw, or cable cutter.
Actual mechanics are encouraged to provide more expert advice, haha.
>Using a tape measure, I approximated the diameter of my wheels at 22.5 inches at the outside of the rim
22.5 inches is 571mm. That’s a 650C standard – if you’ve measured very accurately.
The modern standard for 26″ inch mountain bikes is 559mm – it looks like this is the tyre you have on.
And then printed on your rim is 599 – a very old US standard. We’re talking WW2 era. I don’t know much about this, it’s possible that the “599” is the diameter including the tyre, which may push it closer to your measurements.
It’s very possible that this is an old standard that someone has forced a tyre onto, but if that truly is a standard 26″ mountain bike tyre and a 599 rim, it’s a 40mm difference which would likely be impossible to install.
I’d suggest ignoring the stamps for now, and take some accurate measurements. If it truly is 22.5 inches (571mm), it’s a 650C standard. If it’s actually 559mm then it will take a standard 26″ tyre – which is fairly likely as it looks like it has one installed. If it actually is 599mm I don’t know how that tyre was installed – and you’ll really struggle to find something for it.
Or just take the whole rim into your LBS, and find what fits.
You are within the proper range for your setup.
22 tells you the width of the rim.
You can use a chart to reference compatibility from here, which will also tell you the performance range. When you ask AI, you can say, “What is the performance spec of a (size tire) on a (size rim).”
Other things you should note are that rims sometimes develop deviations in the metal, so you want to check both the rim and tire to make sure there are no metal fragments.
The next thing you need to note is that when riding a wide rim and tire, the pressure is very important. If you are running your pressure too low, this will cause pinch flats. If you are not aggressively checking your tire pressure, but are riding many sessions inbetween, then the pressure is getting knocked out and continuously leading you to a pinch flat. In this case, there is no compatibility issue, but it is an issue of poor maintenance practices.
26″ nominal tire size. Widths from 1.5 to 2.2 inches or so.
Jayzus the chainstay brakes what happened in the late 80s
Judging by the photos, it looks like your rim is mis-stamped 599 when it should have be 559. 599 was obsolete when this bike was made.