Light Bicycle has a very simple table for tire size / rim width compatibility here:
https://www.lightbicycle.com/newsletter/tire-size-chart-for-bicycle-rim.html

According to them, an i25 rim is good for tires from 2.1" to 2.5-2.7", while an i30 rim is good for 2.3" to 2.5-2.7" tires. I'm sure you can make this much more complicated, but I'd say the i26 rim is good for what you want to do, although the i30 rim would give a wider (and arguable better) footprint for the tire sizes you are considering.

 

Yeah, I'd go i25 for that. I use i25 for my XC 29er setup to keep it fast. I run as skinny as 2.1 and as wide as 2.35, they work excellent with both. For only up to a 2.35, I would not go i30.

 

Another vote for the I26 or I24 or whatever; for front and back for xc/trail since you already have i30 for trail/enduro.

But I'm not really much of a believer in fat tires, and so not much of a need for fat rims, so take this opinion for what it's worth. ;-)

 

Thanx for the input guys. I know this sounds a bit hysterical, and I make this complicated, but my experience is you can actually feel if the rim is to wide or to narrow. I think there is a sweet spot. It's all personal and about tyre and situation.

I will never go smaller than 2.35 as the genius is specced for 2.4 to 2.6 for 29. I think i26 is perfect for 2.35 non wt tyre as the rekon race but perhap it kind of limits future upgradability?
I want to keep this 10 years plus and want to be sure I can use it on the future tires. I know...bit difficult to predict or what?

On my ht xc wheelset I run 2.1/2.35 on i26 and it's super. Just to give some impression of my preferabilities.

 

It depends on the tire you choose. 2.35 tires are all very different. It's worthless to generalize with a chart.
Terrain and speed make a big difference too.
The thicker and heavier sidewall you need the skinnier the rim to match it.
And the higher the pressure you run.

Some 2.35s were originally designed when 19-21mm rims were the norm. Their tread profile roundness can get squared off if you run them on wide 30-35mm rims. The outer knobs will dig when cornering.
Some newer tires may have been designed with higher volume and a more rounded tread profile. Those tires can create a big footprint with lower pressure on a wide rim that supports the tire sidewall. The sidewall will wrinkle instead of folding over in cornering. There's the bigger footprint. This gives you a slower more controllable side-out.
My favorite tires for the terrain and uses you've outlined are pretty fast rolling on par with Nobby Nics. But they last longer. Bontrager XR2 Team 2.35s. They also have 120tpi sidewalls for better flexibility. High volume with a very rounded tread profile. 35mm inner for this tire. 40mm for the 2.6. I've run these tires since 2014. Other tires may also be good choices.

I also don't support Mavic wheels. They use proprietary spokes and hubs that don't offer enough offsetting benefits. They're a mid level road bike wheel source at best. Build your own carbon wheels with Sapim spokes and nipples and Dt hubs. Chinese carbon rims from CarbonFan or BTLOS are so close to spec they require minimal truing when you lace them. They're the easiest for a first time builder.

 

Tuned in.

I'm in a similar situation in determining rear rim width, i26 or i29.

I plan on sticking with 2.4" tires that seem to be made for wider rims, spcifically the Bonti XR/SE4.

Like the OP I'd want the ability to also run 2.6" tires. On that point, I know that 2.6" tires feel alot better on a rim at least i30. The benefit of the 2.6" is being able to run low psi. Without the sidewall support of a wider rim they just don't feel right.

 

I ran Racing Ralph 2.35's on I30's and there was not enough rim protection period. Currently have I25 rims running a front Bontrager 2.6 & a Maxxis 2.25 rear.

 

I30 for me on anything 2.3 and larger and some smaller tires that have a large volume casing for their size (2.2 ikon, 2.2 rekon etc).

For the most part on 2.2 and below, I want to be on ~ i26. I don't see any reason for a mtb wheel smaller then i26. Even road bikers are now running 28c tires on 21mm iw wheels and 23mm iw for 32-35c. Absolutely no reason to run a tire 1.5-2x larger on a wheel that size.

 

"c" is not a unit of measurement dude. If you mean mm just say mm.

 

Simmer down forum cop. Road tires are referred to in c sizing up to 37c-40c and then we leave the cyclocross world and transfer over into the real measurement world of mtb. I'm sorry that my reference to the tires as they are listed within the industry offended you and made my post totally intelligible to you and everyone else on this forum. Because of this, the advice i gave is obviously completely useless and should be totally ignored. I'm super glad people like you are here to donate their time correcting all of the injustices of each and every post so that you can make sure people only refer to things as you see fit. :madman:

Ride safe and hopefully don't be too furious at all the terrible posting injustices you have to police.

 

Yes, also bicycle magazine writers and website monkeys use the wrong terminology or confusing terminology. That is why this is so confusing for poor readers.

If you look at the Maxxis list you posted, under the cyclocross tires, you see the Speed Terrane is listed in 28x33mm and 700x33c. So they have taken the "c" from the 700 and moved it to the end, perhaps to save space. But for the 28" tires the c is gone.

Same for the Schwalbe, you'll see there is no "c" when 700 is not mentioned.

So if you are just referring to the carcass size, "c" is not a unit of measurement. "c" is referring to the diameter of the WHEEL.

It isn't that big of a deal until people start confusing 650b with 700c which is happening now that both are used on gravel bikes.

There is no need to thank me for this valuable technical information.