Dirt in the tire?

[Ryan Cousineau]

I raced a 'cross race in dry, dusty conditions a few weeks ago.

Then today, in prepping for a race, I changed my tires. Inside the rim
of the front tire, I found the most curios thing at one place: dirt, a
lot of it, very powdery and tightly packed (it looked like
espresso-grind coffee: very fine).

The dirt was in the rim in a little clod about an inch long. So how did
it get in?

The notable weirdness with cyclocross, of course, is that the received
wisdom is to run the tires with very low pressure. 50 pounds is quite
normal, and 30-40 is not unheard of. The fastest rider I know claims not
to use a pressure gauge: if he can't touch the rim when he presses down
on the tire with his thumb pushed by his other hand, he has enough tire
pressure. Like most serious CXers, he uses tubulars.

My phenomenon happened when I was using clinchers though, because I'm
cheap.

So, did the dirt just get an invitation past the bead during a
near-blowoff? Did I pick it up a little at a time, or in one big scoop?
Any other reports of such strange phenomena?

-RjC.

--
Ryan Cousineau rcou...@sfu.ca http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos

[marcu...@gmail.com]

Ryan Cousineau wrote:
> I raced a 'cross race in dry, dusty conditions a few weeks ago.
>
> Then today, in prepping for a race, I changed my tires. Inside the rim
> of the front tire, I found the most curios thing at one place: dirt, a
> lot of it, very powdery and tightly packed (it looked like
> espresso-grind coffee: very fine).
>
> The dirt was in the rim in a little clod about an inch long. So how did
> it get in?
>
> The notable weirdness with cyclocross, of course, is that the received
> wisdom is to run the tires with very low pressure. 50 pounds is quite
> normal, and 30-40 is not unheard of. The fastest rider I know claims not
> to use a pressure gauge: if he can't touch the rim when he presses down
> on the tire with his thumb pushed by his other hand, he has enough tire
> pressure. Like most serious CXers, he uses tubulars.
>
> My phenomenon happened when I was using clinchers though, because I'm
> cheap.
>
> So, did the dirt just get an invitation past the bead during a
> near-blowoff? Did I pick it up a little at a time, or in one big scoop?
> Any other reports of such strange phenomena?
>
> -RjC.
>

Possibly material wearing off the inside of the tire casing due to
squirming of the tube?

I would not advise brewing and drinking a cup of it.

Marcus

[carl...@comcast.net]

On Sat, 29 Sep 2007 05:23:04 GMT, Ryan Cousineau <rcou...@sfu.ca>
wrote:

>I raced a 'cross race in dry, dusty conditions a few weeks ago.
>
>Then today, in prepping for a race, I changed my tires. Inside the rim
>of the front tire, I found the most curios thing at one place: dirt, a
>lot of it, very powdery and tightly packed (it looked like
>espresso-grind coffee: very fine).
>
>The dirt was in the rim in a little clod about an inch long. So how did
>it get in?
>
>The notable weirdness with cyclocross, of course, is that the received
>wisdom is to run the tires with very low pressure. 50 pounds is quite
>normal, and 30-40 is not unheard of. The fastest rider I know claims not
>to use a pressure gauge: if he can't touch the rim when he presses down
>on the tire with his thumb pushed by his other hand, he has enough tire
>pressure. Like most serious CXers, he uses tubulars.
>
>My phenomenon happened when I was using clinchers though, because I'm
>cheap.
>
>So, did the dirt just get an invitation past the bead during a
>near-blowoff? Did I pick it up a little at a time, or in one big scoop?
>Any other reports of such strange phenomena?
>
>-RjC.

Dear Ryan,

When muddy water gets in through rim holes, settles to the bottom, and
evaporates . . .

Cheers,

Carl Fogel

[Ryan Cousineau]

In article <46fe8312$0$24084$c3e...@news.astraweb.com>,
marcu...@gmail.com wrote:

I doubt it. There was enough that had this much powder worn off the
casing, it would have probably been a hole in the tire! And the tires
are black, but the dirt was brown. Also, I'm pretty sure it was dirt,
not rubber crumb.

> I would not advise brewing and drinking a cup of it.

Good advice!

[Ryan Cousineau]

In article <nb6tf35sd7hsboek8...@4ax.com>,
carl...@comcast.net wrote:

Not impossible, especially since the race before last, which was also
dry and dusty, had, er, a water crossing.