Wide tire / narrow rim combination

Will using a 700c x 32 (& same size tube) on a 13mm (interior width) rim
cause regular flats? I tried doing a 30 mile ride Saturday and had flats
from 3 new tubes. All tubes had holes in the same general area, but not
exactly. All were rim facing holes (torwards the inner part of the wheel,
not the outside). All flats occurred on the rear tire; I've never had on on
the front. A couple of weeks ago I had a similar string of failures on the
same tire, but fine since then. When I was riding 700c x 23's, I rode for
several months without ever having a failure before switching to a larger
tire/tube.

I checked the tire inside & out, and the rim for burrs, glass, etc. The rim
tape is new. I know it's not rocket science, but what am I missing?

Cheers!

On Mon, 08 Aug 2005 11:25:40 -0500, Dukester wrote:

I know it's not rocket science, but what am I missing?

Were the tires properly inflated? That's the only basic thing you didn't
mention. They sound like pinch flats. Also, was the tube properly
installed? Sometimes a bit of it can get pinched between the tire bead and
rim--this happens more easily with wide tubes. Other than that, I'm not
sure if it's a rim/tire issue.

If you wanna try something narrower, Nashbar still has those Hutchinson
Flash tires for 4.95 a pop. :P (700x28)

"maxo" wrote in message
news
On Mon, 08 Aug 2005 11:25:40 -0500, Dukester wrote:

Were the tires properly inflated? That's the only basic thing you didn't
mention. They sound like pinch flats. Also, was the tube properly
installed? Sometimes a bit of it can get pinched between the tire bead and
rim--this happens more easily with wide tubes. Other than that, I'm not
sure if it's a rim/tire issue.

They were inflated to the recommended pressure. Asking whether the tube was
properly installed is kind of a loaded question; that is, if I say "No",
well duh, there you are. If I answer "yes" then the reply is "Are you
sure!?" All I can say is I never had a flat where the puncture (from
whatever cause) was facing inward torwards the rim as these were.

Dukester wrote:
Will using a 700c x 32 (& same size tube) on a 13mm (interior width) rim
cause regular flats?

According to Sheldon Brown's chart at
http://www.sheldonbrown.com/tire_sizing.html,
that's not a good combination.

He doesn't suggest pich-flats as a likely result, but if it's a tire
with a soft sidewall I bet it would.

I use the same size tire on Mavic touring rims, which I believe are
something like 4mm wider than a typical racing rim.

RichC

Dukester wrote:
Will using a 700c x 32 (& same size tube) on a 13mm (interior width) rim
cause regular flats? I tried doing a 30 mile ride Saturday and had flats
from 3 new tubes. All tubes had holes in the same general area, but not
exactly. All were rim facing holes (torwards the inner part of the wheel,
not the outside). All flats occurred on the rear tire; I've never had on on
the front. A couple of weeks ago I had a similar string of failures on the
same tire, but fine since then. When I was riding 700c x 23's, I rode for
several months without ever having a failure before switching to a larger
tire/tube.

I checked the tire inside & out, and the rim for burrs, glass, etc. The rim
tape is new. I know it's not rocket science, but what am I missing?

What kind of rim tape? Thick cloth or nylon that protects the tube from
burrs on the spoke holes, or thin rubber might-as-well-not-bother rim
strip?

Do the holes in the tube line up with spoke holes?

--
Warren Block * Rapid City, South Dakota * USA

"Warren Block" wrote in message
...
Dukester wrote:

What kind of rim tape? Thick cloth or nylon that protects the tube from
burrs on the spoke holes, or thin rubber might-as-well-not-bother rim
strip?

It's rubber but I can't feel the spoke ends through it, and I'm pressing
pretty hard to feel for it.

Do the holes in the tube line up with spoke holes?

It looks more like the holes in the tubes line up with the rim sides.

"Dukester" wrote: (clip) It looks more like the holes in the tubes line up
with the rim sides.
^^^^^^^^^^^^^
And, as a "clincher," does is the shape of the hole a little slit, parallel
to the edge of the rim. rather than a round hole?

Dukester wrote:
What kind of rim tape?
It's rubber but I can't feel the spoke ends through it, and I'm pressing
pretty hard to feel for it.

Is it rubber tape or a rubber band with out glue? I had a problem
with the cloth rim tape coming lose and sliding causing the spoke hole
to be exposed and causing me flats. The LBS put on a what look like a
large thick rubber band right over the old tape and that fixed it
except now it's a little harder to get the tire on and off because the
rubber takes up room. Also, I wonder if the original rim tape glue came
lose because I oiled the spoke nipples?

John

Dukester wrote:
Will using a 700c x 32 (& same size tube) on a 13mm (interior width) rim
cause regular flats?

I've run tires as wide as 2.6" on rims that narrow without any unusual
problems with punctures. (I had other sorts of problems, but not
excessive puctures.)

It is normal to mount 40+mm road tires and 50+mm MTB tires on rims of
16-20mm interior width. That's a larger mismatch of widths than what
you describe.

I tried doing a 30 mile ride Saturday and had flats
from 3 new tubes. All tubes had holes in the same general area, but not
exactly. All were rim facing holes (torwards the inner part of the wheel,
not the outside). All flats occurred on the rear tire; I've never had on on
the front.

It sounds to me like you have a problem with your rim strip.

You mention that your rim strips are rubber, but you have also said
that your rime is 13mm in interior width. To my knowledge, no
single-walled rims are that narrow, and rubber rim strips are
categorically unsuitable for double-walled rims.

If you are using a rubber rim strip with a double-walled rim, it's
probably sinking into the holes when the tire is inflated and allowing
the holes' edges to cut into the tube.

Chalo Colina

"Dukester" wrote:

Will using a 700c x 32 (& same size tube) on a 13mm (interior width) rim
cause regular flats? I tried doing a 30 mile ride Saturday and had flats
from 3 new tubes. All tubes had holes in the same general area, but not
exactly. All were rim facing holes (torwards the inner part of the wheel,
not the outside). All flats occurred on the rear tire; I've never had on on
the front. A couple of weeks ago I had a similar string of failures on the
same tire, but fine since then. When I was riding 700c x 23's, I rode for
several months without ever having a failure before switching to a larger
tire/tube.

I checked the tire inside & out, and the rim for burrs, glass, etc. The rim
tape is new. I know it's not rocket science, but what am I missing?

I'm going to go out on a limb and guess that your tubes are for 23mm
tires. That can cause spontaneous flats for very little reason,
including a rough edge on a section of rim tape.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame