MTB - Rim width vs. Tire width

Peder said:

At what point would I need to be concerned about
increasing rim width as I go to wider tires? I'm now using
Maxxis High Rollers 2.35 on Mavic X-139 rims. Thanks for
reading.

The ideal is something like 1.5x rim width, but MTBs break
this rule by a long way. It depends to some extent on the
pressure - tyres at a high pressure (say 80psi+) are more
likely to be damaged against the sidewall of the rim if they
are too fat. Also, some tyres have much better anti-chafing
strips than others and will withstand this treatment.

Zog The Undeniable <[email hidden]> wrote in
news:40eadf1c.0@entanet:

Quoted message said:

Peder said:

At what point would I need to be concerned about
increasing rim width as I go to wider tires? I'm now
using Maxxis High Rollers 2.35 on Mavic X-139 rims.
Thanks for reading.

The ideal is something like 1.5x rim width, but MTBs break
this rule by a long way. It depends to some extent on the
pressure - tyres at a high pressure (say 80psi+) are more
likely to be damaged against the sidewall of the rim if
they are too fat. Also, some tyres have much better anti-
chafing strips than others and will withstand this
treatment.

Thanks for the reply. I managed to find a link to a doc
somewhere on Mavic's site showing "1,5 à 2,3" so I guess at
2.35, I'm just barely over max. Interesting they recommend
lower pressures at wider widths (like 45 psi). Suppose it
would blow the wheel or blow off?

--
Peder (Please reply to group only, email invalid)

Peder wrote:

Interesting they recommend lower pressures at wider
widths (like 45

Quoted message said:

psi). Suppose it would blow the wheel or blow off?

don't wider tires generally run at lower pressures?

dave

Bay Area Dave <[email hidden]> wrote in
:"]news:[email hidden]:

Quoted message said:

Peder wrote:

Interesting they recommend lower pressures at wider
widths (like 45

Quoted message said:

psi). Suppose it would blow the wheel or blow off?

don't wider tires generally run at lower pressures?

dave

I guess I didn't write that very well. What I meant was
would the max listed tire pressue of 65 psi break the wheel
or tend to blow off.

--
Peder (Please reply to group only, email invalid)

Peder said:

Bay Area Dave <[email hidden]> wrote in
:"]news:[email hidden]:

Quoted message said:

Peder wrote:

Interesting they recommend lower pressures at wider
widths (like 45

Quoted message said:

psi). Suppose it would blow the wheel or blow off?

don't wider tires generally run at lower pressures?

dave

I guess I didn't write that very well. What I meant was
would the max listed tire pressue of 65 psi break the
wheel or tend to blow off.

oh, are you wondering if one installs a tire LARGER than is
recommended for a particular wheel, will it tend to come off
easily due in part to running it a lower pressure than the
correct tire would be run at? If that's your question, I
don't have an answer. 🙂

dave

Quoted message said:

I guess I didn't write that very well. What I meant was
would the max listed tire pressue of 65 psi break the
wheel or tend to blow off.

No. I run a 2.4 on my Mavic X223 rim and they are just fine.

--
Phil, Squid-in-Training

Quoted message said:

At what point would I need to be concerned about increasing
rim width as I go to wider tires? I'm now using Maxxis High
Rollers 2.35 on Mavic X-139 rims. Thanks for reading.

There is a table listing recommended tire sizes for various
rim widths at tandem-fahren.deReifentipsOpen ↗
The text is in German, however. The table is meant for
tandem riders, but a lot of mtb riders seem to use much
wider tires than suggested by this table.

--
Ned Mantei Department of Cell Biology, Swiss Federal
Institute of Technology CH-8093 Zurich, Switzerland

back in my weight-weenie days i ran 26" aero road rims (sun
something-or-others) on my mtb. 26x2.0 tires stayed on just
fine, and the wheels were surprisingly durable. brake
adjustment was finicky though...skinny kool-stops were
required to prevent the pads from rubbing the bulging
sidewalls when the brakes were not being applied while
preserving reasonable lever travel.

fwiw,

dookie

Quoted message said:

At what point would I need to be concerned about
increasing rim width as I go to wider tires? I'm now using
Maxxis High Rollers 2.35 on Mavic X-139 rims. Thanks for
reading.

--
Peder (Please reply to group only, email invalid)

"dookie" <[email protected]> wrote in
:"]news:[email hidden]:

Quoted message said:

back in my weight-weenie days i ran 26" aero road rims
(sun something-or-others) on my mtb. 26x2.0 tires stayed
on just fine, and the wheels were surprisingly durable.
brake adjustment was finicky though...skinny kool-stops
were required to prevent the pads from rubbing the bulging
sidewalls when the brakes were not being applied while
preserving reasonable lever travel.

I've been wondering about this, ever since the topic came
up.

I'm riding a '92(?) Trek Multitrack 7600 hybrid, converted
to drop bars and STI. I use it as a townie/light trail
riding bike. I'm still on the original 700c rims, which are
Trek-brand "Journey", measuring about 14mm at the gap across
the top. The bike came with 38c tires from the factory on
these rims, and I've stayed in that 35-42c range ever since.

But I see from various sites online (including Sheldon's),
that the "recommended" range of tire widths for this width
of rim is smaller. And some of the aftermarket tires I've
bought over the years do bulge out more than the original
Trek-branded 38c tires... like the IRC Metro II 38c slicks
I'm running now. The bulge just barely clears the canti
brakes, but it works.

Is there actually some danger or drawback in using wider
tires on a narrower rim like this? I have flats now and
then, but nothing I'd consider unusual. I'm thinking "if it
ain't broke don't fix it"... but if there is some
catastrophic failure mode that could happen in the future,
I'd like to know about it.

--
Mike Barrs