CycloCross: Dismount/Run vs Jump?

[Crossposted into rbr since it seemed appropriate]

On Jan 31, 1:28*pm, Chalo wrote:
Keiron wrote:

Tim McNamara wrote:

*Many 'cross
course designers (those who understand the difference between a 'cross
course and a MTB course) try to place barricades in such as way as to
minimize this advantage.

What are the principal differences in course design between
[cyclocross] and mtb??

Cyclocross has a long tradition of using the wrong tool for the job,
which for decades was uninterrupted because there were so few people
who thought it a good idea to ride any kind of bike in the freezing
mud during winter.

When MTBs arose, they turned out to be unbeatably better at riding
cross-country on unprepared surfaces than any sort of road bike with
knobbies. *Cyclocross being enamored of its long tradition of using
the wrong tool for the job, its organizers made two changes to ensure
the place of the road bike in this off-road sport.

First, they banned tires more than 35mm wide, because wide tires work
a _lot_ better on cruddy surfaces such as dirt, mud, and rocks.
Allowing appropriate tires for conditions would give an insurmountable
advantage to bikes that can fit appropriate tires (which traditional
'cross bikes cannot).

Second, CX courses began to focus on features like steep rough climbs
without reasonable approaches, short fences, sand pits, stairs, and
other such things that make it more practical to tote your bike as
luggage while you waddle through or over them rather than riding
through them. *This gave a small but significant advantage to bikes
that are better at being carried than being ridden in those
conditions.

I think that the evolution of cyclocross course
design that you are talking about may describe
what happened in the US rather than what happened
in Europe, and the driving force was not be trying
to weed out MTBs but trying to move towards
courses after the European style.

For an example of what I'm talking about, see this
archived discussion between Jeff Clark and Casey
Kerrigan on the history of Norcal CX course design:

http://web.archive.org/web/200503251.../surfhist..htm

The Euro-influence discussion is after the recollections
of Bob Leibold jungle-cross courses, skip down to
where Jeff says:
"The turning point for me was in '93 or '94 when I saw my
first world championship video. I don't remember the
location of the event, but it was an eye-opener. The start
was crit-style on pavement, and the group stayed together
for the first several laps. There were wide straightaways &
turns, with groups of riders negotiating 20' wide obstacles
at speed. ..."
"The SCCX transition to the "euro" style was a result of the
need to give the riders more room, and the pie-the-sky desire
to provide more adequate training for international competition. "

Now of course, maybe the Euros had changed their
courses to weed out pernicious MTBs. But I doubt it.
Riding MTBs in cross races has usually been okay
in non-UCI races in the US, but I don't think it was
ever a factor in Europe, where cross is a professional
sport rather than grass-roots and at-best-semi-pro
as it is here.

When we talk about the evolution to "Euro-style" courses,
it's not the introduction of dismounts. Dismounts were
part of cross long before MTBs. It's more the wider courses
and faster sections. This changes the race, and the
primary effect is not strictly an equipment issue of disfavoring
MTBs. In jungle-cross or MTB racing courses, opportunities
to pass slower riders are rare, and there's rarely a
benefit to drafting. In a wider, faster course, it's
easier to pass (this is one reason larger turnouts
forced wider courses), and drafting and tactics - will
riders work together or attack each other? - play a role.

The top-grade cyclocross racers are great bike handlers
and it is often surprising what they can ride on road bikes
with comparatively skinny tires. In a section where you
and I might see a benefit to MTBs, they don't need them.
In local races where people can choose their bike and
the course is often more jungley than Euro-style, the
fastest people almost always ride CX bikes. (The one
exception I knew in Norcal was "Mountain Larry"
Hibbard.)

Ben

P.S. One minor nitpick. Wider tires are often better
on loose surfaces and gravel, but not on mud. A lot
of expert racers will tell you that fat tires tend to slide
around on mud while moderate-width CX tires cut
through or compress it down enough to ride on.
In my inexpert experience, they have a point.

On Jan 31, 9:51*pm, "
wrote:

P.S. One minor nitpick. *Wider tires are often better
on loose surfaces and gravel, but not on mud. *A lot
of expert racers will tell you that fat tires tend to slide
around on mud while moderate-width CX tires cut
through or compress it down enough to ride on.
In my inexpert experience, they have a point.

This is true of deep sand too. We do cx races at Boulder Reservoir
that usually include a deep sandy beach descent. A friend of mine with
significant MTB racing experience switched from a cross bike to an MTB
mid-race due to a mechanical and mentioned afterward how badly the MTB
floundered in the deep sand.

More generally, lots of MTB folk enter the sport with a MTB or a cross
bike with flat bars and eventually move to a more appropriate drop bar
bike bike when they realize the disadvantage.

Bret

Bret wrote:

Ben wrote:

Wider tires are often better
on loose surfaces and gravel, but not on mud. *A lot
of expert racers will tell you that fat tires tend to slide
around on mud while moderate-width CX tires cut
through or compress it down enough to ride on.
In my inexpert experience, they have a point.

This is true of deep sand *too. We do cx races at Boulder
Reservoir that usually include a deep sandy beach descent. A
friend of mine with significant MTB racing experience
switched from a cross bike to an MTB mid-race due to a
mechanical and mentioned afterward how badly the MTB
floundered in the deep sand.

My own experience with deep dry sand and gravel (in local playgrounds
and Gulf Coast beaches) is that my MTB with 3" tires consumes
prodigious amounts of my muscle power digging its way through, but my
street bikes with 32-40mm tires are more likely to stop dead in their
tracks.

I avoid riding my bikes in mud like I avoid bashing them with things
that would leave dents, or like I avoid hacking rocks with my kitchen
knives. My limited experience with mud in the street suggests that
fat tires, skinny tires, and my shoes will all slide on it when I
would rather they didn't.

Chalo

In article
,
Chalo wrote:

Bret wrote:

Ben wrote:

Wider tires are often better
on loose surfaces and gravel, but not on mud. *A lot
of expert racers will tell you that fat tires tend to slide
around on mud while moderate-width CX tires cut
through or compress it down enough to ride on.
In my inexpert experience, they have a point.

This is true of deep sand *too. We do cx races at Boulder
Reservoir that usually include a deep sandy beach descent. A
friend of mine with significant MTB racing experience
switched from a cross bike to an MTB mid-race due to a
mechanical and mentioned afterward how badly the MTB
floundered in the deep sand.

My own experience with deep dry sand and gravel (in local playgrounds
and Gulf Coast beaches) is that my MTB with 3" tires consumes
prodigious amounts of my muscle power digging its way through, but my
street bikes with 32-40mm tires are more likely to stop dead in their
tracks.

Hard to say, but you might want to watch some Euro-pro CX videos.
There's a few sand-centric races every year that feature riders powering
through the sand with their 32mm tires.

I avoid riding my bikes in mud like I avoid bashing them with things
that would leave dents, or like I avoid hacking rocks with my kitchen
knives. My limited experience with mud in the street suggests that
fat tires, skinny tires, and my shoes will all slide on it when I
would rather they didn't.

Very open tread compounds are the key, but all mud is not created equal.
The mud here in the PNW tends to clear from reasonable tires fairly
easily. I have heard tales of clay-based muds that pack onto every
surface of the bike, never leave, and harden there.

That sort of thing might change my attitudes to riding in the mud.

--
Ryan Cousineau http://www.wiredcola.com/
"In other newsgroups, they killfile trolls."
"In rec.bicycles.racing, we coach them."

On Feb 1, 10:41 am, Ryan Cousineau wrote:

I have heard tales of clay-based muds that pack onto every
surface of the bike, never leave, and harden there.

Indeed. The bentonite clay of the Mancos formation that lies exposed
near Durango and large parts of Utah is a prime example. About five
seconds worth of riding through it can stop the bike cold.

"Ryan Cousineau" wrote in message
]...

Very open tread compounds are the key, but all mud is not created equal.
The mud here in the PNW tends to clear from reasonable tires fairly
easily. I have heard tales of clay-based muds that pack onto every
surface of the bike, never leave, and harden there.

That sort of thing might change my attitudes to riding in the mud.

There is a mix of earth types in the Bay Area. While most of the mud is
sticky but loose enough to clear, if you don't have enough clearance a lot
of it will seize your wheels solid. And in case of Garin & Dry Creek Pioneer
in Hayward, the mud is so sticky that two of us were stopped cold only 100
yards up the trail. We had to CARRY the mountain bikes with tons of
clearance back and throw both of them in the lake and let them sit there for
15 minutes and it STILL took scrubbing and pushing that mud off with sticks
to get them to the point where you could ride them again.

Needless to say I've never been back there off-road in the winter again.

Ryan Cousineau wrote:

*Chalo wrote:

I avoid riding my bikes in mud like I avoid bashing them with things
that would leave dents, or like I avoid hacking rocks with my kitchen
knives. *My limited experience with mud in the street suggests that
fat tires, skinny tires, and my shoes will all slide on it when I
would rather they didn't.

Very open tread compounds are the key, but all mud is not created equal.
The mud here in the PNW tends to clear from reasonable tires fairly
easily. I have heard tales of clay-based muds that pack onto every
surface of the bike, never leave, and harden there.

That sort of thing might change my attitudes to riding in the mud.

Austin gets about the same yearly precipitation as Seattle. Seattle
gets it thinly distributed over 200 days. Austin gets it in a small
number of Biblical deluges. Generally speaking, Seattle rain gets
everything in and around the street filthy, and Austin rain makes
things pretty clean, streets included. With a few small exceptions.

In my neighborhood, there are many folks who started their lives in
Mexico. One of the cultural habits some of them brought with them was
the tendency to sweep their yards daily, with or without watering, to
maintain a surface of smooth bare dirt as a kind of outdoor floor.
When the angry rain god of Central Texas goes on a bender, yards thus
surfaced dump a lot of fine silt directly into the gutter.

For a while after they arrive in the street, these silt accumulations
might as well be grease for all the traction they afford. Sometimes
the silt deposits can look like an insignificant film, when in reality
they are deep enough that no treaded tire or shoe will cut through
them to find the hard surface underneath. This is the basis of my
experience with mud for the last couple of years: Encounter some mud,
have a near- or actual fall.

When in the distant past I sometimes rode on trails, I found the mud
messy. abrasive, and sometimes smelly; I almost always attempted to
route around it. It was not nearly as lubricious as East Austin
street mud.

Chalo

On Feb 2, 1:23*pm, Chalo wrote:
Ryan Cousineau wrote:

*Chalo wrote:

I avoid riding my bikes in mud like I avoid bashing them with things
that would leave dents, or like I avoid hacking rocks with my kitchen
knives. *My limited experience with mud in the street suggests that
fat tires, skinny tires, and my shoes will all slide on it when I
would rather they didn't.

Very open tread compounds are the key, but all mud is not created equal..
The mud here in the PNW tends to clear from reasonable tires fairly
easily. I have heard tales of clay-based muds that pack onto every
surface of the bike, never leave, and harden there.

That sort of thing might change my attitudes to riding in the mud.

Austin gets about the same yearly precipitation as Seattle. *Seattle
gets it thinly distributed over 200 days. *Austin gets it in a small
number of Biblical deluges. *Generally speaking, Seattle rain gets
everything in and around the street filthy, and Austin rain makes
things pretty clean, streets included. *With a few small exceptions.

In my neighborhood, there are many folks who started their lives in
Mexico. *One of the cultural habits some of them brought with them was
the tendency to sweep their yards daily, with or without watering, to
maintain a surface of smooth bare dirt as a kind of outdoor floor.


No grass in the yards in Austin? Yards of bare dirt?





When the angry rain god of Central Texas goes on a bender, yards thus
surfaced dump a lot of fine silt directly into the gutter.

For a while after they arrive in the street, these silt accumulations
might as well be grease for all the traction they afford. *Sometimes
the silt deposits can look like an insignificant film, when in reality
they are deep enough that no treaded tire or shoe will cut through
them to find the hard surface underneath. *This is the basis of my
experience with mud for the last couple of years: *Encounter some mud,
have a near- or actual fall.

When in the distant past I sometimes rode on trails, I found the mud
messy. abrasive, and sometimes smelly; I almost always attempted to
route around it. *It was not nearly as lubricious as East Austin
street mud.

Chalo- Hide quoted text -

- Show quoted text -

"Chalo" wrote in message
...

For a while after they arrive in the street, these silt accumulations
might as well be grease for all the traction they afford. Sometimes
the silt deposits can look like an insignificant film, when in reality
they are deep enough that no treaded tire or shoe will cut through
them to find the hard surface underneath. This is the basis of my
experience with mud for the last couple of years: Encounter some mud,
have a near- or actual fall.

That's why you keep a spare pair of wheels with cyclocross tires on them.

Avocet used to make a "reverse" knobby that was a smooth tire with very deep
and wide tread. These things were sort of like the Dunlap Universal tires
that were so popular among motorcyclists in the 60's. They rolled well on
hard roads but also worked well on poorer traction surfaces. Unfortunately
they stopped making them.

On Feb 1, 1:31*am, Chalo wrote:

My own experience with deep dry sand and gravel (in local playgrounds
and Gulf Coast beaches) is that my MTB with 3" tires consumes
prodigious amounts of my muscle power digging its way through, but my
street bikes with 32-40mm tires are more likely to stop dead in their
tracks.

Here's a picture of Niels Albert not being stopped dead is his tracks
by deep sand today:
http://www.cyclingnews.com/cross.php...90204ispa-0274

Bret