Mountain Bike

http://www.sheldonbrown.com/rim-sizing.html

>>1017563

http://www.schwalbe.com/en/reifenmasse.html

>>1017563

$0.50 plastic calipers.

>>1017563

Internal width is what matters

If you ride low pressure for comfy you should be conservative with the size. Stay inside the Sheldon chart

If not you will experience tire flop, where the tire folds over a bit on turns and feels unstable

MTB bros seem to regularly put huge tires on nature rims and pump then up to high pressures without issues. I don't know about MTB but it seems stupid and is probably not good

>>1017701
The Schwalbe table posted in >>1017640 is more accurate than the conservative one on Sheldon's site. Basically on any 19mm or wider rim (the vast majority of MTB rims) it's fine to run any width tyre that's not marketed as fat or plus sized (so up to around 2.4).

Of course the narrower your rim is relative to the tyre to more it's going to roll but it's not going to be a (dangerous) issue until you get to really low pressures, at which point you'll probably want to be running tubeless to avoid pinch flats and if you've got the money and knowledge for that you should know and can afford to get some wider rims.

>>1017701
>MTB bros seem to regularly put huge tires on nature rims and pump then up to high pressures without issues. I don't know about MTB but it seems stupid and is probably not good

The source of these charts is ETRTO, and for some reason, ETRTO likes to put HUGE fat tires on skinny rims.
That may have been the fashion back when they started this bicycle-tire-measuring standard (1969) and they have refused to change it to avoid breaking the standard system.

In short--the ETRTO rim/tire charts are shit. Ignore them.

Here is a better rule to follow:
The tire width should be at least as wide as the outside rim width, and no more than 1.5X the external rim width.

That cuts the available tire sizes for any rim way down, but it cuts it down to the combinations that work well.
Fat tires on skinny rims don't work well, and some of the ETRTO combinations say it's okay to use a tire that is almost 2.5X as wide as the rim.

It's also a lot easier to get wide MTB rims now, in the era of disk-only wheels.
It's not hard to find wheelsets for $150 that have 40mm [aluminum] rims, and you can get fairly-cheap aluminum rims up to 80mm wide.

>>1017709
>The Schwalbe table posted in >>1017640 is more accurate than the conservative one on Sheldon's site.
The page claims it's an ETRTO chart too. It may be a later-edition one than the one that's been on the Sheldon site forever.
The funny thing here is, the newer one is more ridiculous: it advises using even fatter tires on skinny rims...

On the old Sheldon chart, the tire width range for a 17mm rims was states as 25mm to 37mm.
On the (newer?) Schwalbe chart, for the same rim the range is given as 25mm to 52mm tires...? 52mm is 3X as wide as 17mm!

The ETRTO regulations cost a couple hundred bucks for a copy.
From bits I've seen posted around online, they're very silly.

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I run 2.4's on 18mm internal width rims on my XC bike, no problems after 20+ rides.

>>1017842
Also if you do intense ass trail, just go nobby nic 2.4+ on both front and rear.

Currently running Der Baron 2.4 on front, Rock Razor on back... Rock Razor 2.4 is a great rear tire, but the Baron is waaaaaay too skinny for a 2.4.. more like 2.2.

Traction is king and confidence inspiring.

>>1017563
Why does literally everybody have those tires?

>>1017838
>no more than 1.5X the external rim width.
So you're telling me I can't even use 2.0 tyres on my ~32mm rims? Bullshit, I can run 2.6s (62mm) perfectly fine.

>>1017843
How is the wear rate on the rock razor? A lot of reviews say they're basically done after 200km

>>1017843
Ive put 4" wide fat tires on a stock mtb rim 22mm i belive. Works fine. Faggot

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>>1017848
>So you're telling me I can't even use 2.0 tyres on my ~32mm rims? Bullshit, I can run 2.6s (62mm) perfectly fine.
Not really.
I didn't say that you can't use it; I said it wouldn't work well.
And it doesn't.
You've just never used any better combo, so you don't know that.

Consider the following, in order-
1. The reason to use fat tires is to inflate them to lower pressures, to absorb bumps better.
2. If you put fat tires on skinny rims, you can't lower the pressure much because the tires squirm and fold over in turns.
3. So all you end up with if you do this is a really heavy, hard wheel & tire setup.

If you want 2.5" tires all the time then do yourself a favor and get some rims that are 40mm - 50mm wide. You would be able to run much lower pressures, get much better comfort and still have them handle well.

>>1017866
I've had mine for well over 200k and they still look good.

I imagine if you're using it for very rough downhill that 200k is accurate... but most will give after that.

It's honestly the highest quality tyre I've used out of:

- WTB Trail King
- WTB Nano
- WTB Nine Line
- Continental Der Baron (disappointed with quality here).

Schwalbe makes great product.

>>1017989
Total bullshit, I'm guessing this is all crap you've read and never actually tried. Plenty of people run tyres greater than 1.5x the rim width and it works great.

>>1017842
What pressure? I ran a 2.35" on a 17mm width rim (old Mavic Crossmax), and while it worked at higher pressures, at low pressures I could feel the tire squirming in fast turns and it was really confidence destroying on descents. Now I'm running 25mm wide rims with a 2.35" on the front and a 2.2" on the back, and it's waaaay better. I can get the pressure so low that I start to worry about denting the rims before I feel tire squirm.

26" rims and tubeless, btw.

Also,
>20+ rides
>Like that's a real accomplishment

>>1017889
I'm sure it "worked", but that's not the same thing as working well. Have you ever ridden 4" wide tires on 50-80mm wide fatbike rims?

>>1017989
>40-50mm wide rims for 2.5" tires
waaaat.jpg

That's crazy town.

Stan's recommends 2.0" to 2.25" tires on the Crest (23mm internal), 2.25" to 2.5" on the Arch (26mm internal), and 2.35" to 2.8" on the Flow (29mm internal). That's a Tire:Rim width ratio of 2.1 to 2.5

WTB's big Scraper rims come in 40mm and 45mm widths. They recommend a 2.8" on the 40mm and a 3.0" on the 45mm - Tire:Rim ratios of 1.8 to 1.7

Recommending people use tires "No wider than 1.5x as wide as their rims" is straight up wrong, at least for MTB tires in the 2" to 3" width range (I know fatbike people are doing wild stuff with 4-5" wide rims but I don't have any direct experience there). Using 1.5 as the MINIMUM tire:rim width ratio instead of as the maximum would be more correct.

Yeah, you get more air volume when you spread the tires onto wider rims, but it distorts the tread and exposes the sidewalls to more cuts.

>>1017991
I had Der Barons before and I found they gripped very well when I came onto rocks/roots/ruts at odd angles but they didn't have a very smooth ride quality and they felt strange cornering, not at all confidence inspiring.

Now I have Hutchinson Squales and they ride super smooth but they don't have the same ability to grip onto the edge of things... Thinking about trying Maxxis Ardent 2.4s next, or maybe an Ardent rear and a HR2 front or something..

>>1017842
i've got 2.3s on 19mm rims and the rim seems a little on the small size, i would love to get some 28mm but i'm too cheap to buy new rims.

> multiple informed posters mention that your pressure is most important

> MTB retards chime in about their 4" tires on skinny rims at 100 psi

Never change, babes

>>1018272

Rhyolites and the xl version are the cheapest option.

Impossible to get write bead tires on them though. Very tight fit all tire options imhe

>>1017563
the answer is to always run minions at 28-35 psi, depending on trail conditions.