CycloCross: Dismount/Run vs Jump?

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."

In article
,
" wrote:

On Feb 1, 8:23*am, " wrote:
On Feb 1, 12:35*am, Bret wrote:

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

the
fastest people almost always ride CX bikes. *(The one
exception I knew in Norcal was "Mountain Larry"
Hibbard.)

I did a Central Coast with Larry and was very impressed. CO's answer
to Larry is Travis Brown.

http://tinyurl.com/ddthdf

Bret

Is that picture typical of cross races where you live? *The whole idea
of a cross race interests me, except for the mud part. *I hear guys
all the time talking about slipping, sliding, muddy circles in
describing cross tracks. *I'd rather not feel the need to rebuild my
bike after ever race, and the only bike I have that I wouldn't rebuild
after such a race is my cheap-o rigid SS 29er. *Problem is, I can't
even hop on that bike.

The course you in that picture looks like it would be real fast on my
26"MTB, or maybe even a tall geared BMX. *Do they allow BMX bikes in
amature races? *Are there any with few enough fast sections (20MPH+
maybe? *been a while since I clocked myself on a BMX) that a BMX might
be competitive? *I can't hop anything with drop bars more than a
couple inches, but I can ride my BMX over/up most things, even if it
involves casing a rear wheel.

I just realized that was a set of pictures and scrolled through them
all. Definitely too fast for a BMX, but it looks like it'd be pretty
quick on a MTB, especially if that enabled you to jump more of the
barriers. Is there some sort of penalty (besides the chance of a
pinch flat) if you hit one of these? http://tinyurl.com/d24lxs

Do they get knocked over, or are they solid? Are you DQd? Penalized
a lap?

http://www.cyclingnews.com/photos.ph.../XilinxCX/21xl
nx_cross_102603_21

Those barriers are limited to a max height of 40cm by CX course design
standards. Those vertical supports you can see are pieces of rebar which
then sink a foot or more into the ground, whatever is necessary to keep
them upright despite occasional (or frequent) impacts from clumsy
riders. They're intended to be perfectly rigid. There would be no
penalty for knocking them over in the normal course of the race.

You can ride them if you are able, but organizers often try to make that
harder by putting the barriers closer together or putting three in a
row. These ones are about the widest-spaced set of doubles I've seen.

These barriers are a mainstay of amateur CX racing because they're easy
to set up and easy to move. In the pro level, barriers are much rarer,
partly because they're not that hard for pros to ride. Stairs and steep,
loose-traction run-ups are most common Euro-pro obstacles that are
intended to force dismounts.

I always pictured cross races to look like the top picture here
http://tinyurl.com/bk3tkh

I just don't want to do that to a decent bike with gears and whatnot,
and wouldn't want to race on a beater SS.

That picture is from a road race (Paris-Roubaix). Conditions in CX races
can be much worse.

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

" writes:

I just realized that was a set of pictures and scrolled through them
all. Definitely too fast for a BMX, but it looks like it'd be
pretty quick on a MTB, especially if that enabled you to jump more
of the barriers. Is there some sort of penalty (besides the chance
of a pinch flat) if you hit one of these? http://tinyurl.com/d24lxs

Do they get knocked over, or are they solid? Are you DQd?
Penalized a lap?

You usually crash. Hard. The barricades are usually solidly
anchored.

A point that should be made is that, as in all sports, there is an
aesthetic and an etiquette. In cyclo-cross it is the use of a
road-ish bike to do this stuff.

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.

On Feb 1, 12:57*pm, Tim McNamara wrote:

A point that should be made is that, as in all sports, there is an
aesthetic and an etiquette. *In cyclo-cross it is the use of a
road-ish bike to do this stuff.

dumbass,

in cross this happens to have been made the case - i.e. that the sport
is defined by the equipment that is allowed to be used, but it makes
more sense to pick the bike to suit the event and define the event by
the type of course.

in the past cross courses (in n.america) tended to be like mtn. bike
courses (singletrack, rocky sections), but the UCI course guidelines
require the course to be at least 3m wide and a wide paved/smooth
start finish. technical descents are also discouraged. so on a well
designed cross course, a 'cross bike would be the fastest bike.

On Feb 1, 12:23*am, Bret wrote:

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.

dumbass,

a lot of crossers used to use flat bars (look at old videos of
pontoni), but the UCI rules forced the use of drop bars.

Amit Ghosh writes:

On Feb 1, 12:57*pm, Tim McNamara wrote:

A point that should be made is that, as in all sports, there is an
aesthetic and an etiquette. *In cyclo-cross it is the use of a
road-ish bike to do this stuff.

dumbass,

And I am sure that you're a charming fellow yourself. For what reason
did you feel I merited this sobriquet? Or are you just one of the
regular r.b.r. morons who randomly spew useless trash talk at others?
I am always sorry to see threads crossposted to the sad excuse for a
newsgroup that r.b.r. has become.

in cross this happens to have been made the case - i.e. that the sport
is defined by the equipment that is allowed to be used, but it makes
more sense to pick the bike to suit the event and define the event by
the type of course.

Ye-es, that is in agreement with my posts.

in the past cross courses (in n.america) tended to be like mtn. bike
courses (singletrack, rocky sections), but the UCI course guidelines
require the course to be at least 3m wide and a wide paved/smooth
start finish. technical descents are also discouraged. so on a well
designed cross course, a 'cross bike would be the fastest bike.

I have already made those points. Thank you for agreeing.

On Sun, 01 Feb 2009 15:34:10 -0600, Tim McNamara
wrote:

Amit Ghosh writes:

On Feb 1, 12:57*pm, Tim McNamara wrote:

A point that should be made is that, as in all sports, there is an
aesthetic and an etiquette. *In cyclo-cross it is the use of a
road-ish bike to do this stuff.

dumbass,

And I am sure that you're a charming fellow yourself. For what reason
did you feel I merited this sobriquet?

You cross-posted in rec.bicycles.racing. "Dumbass" means "Hello" in
rbr.

JT

On Feb 1, 12:28 pm, Tim McNamara wrote:
In article
,



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.

Cyclo-cross started in a Parisien park and road bikes were all they had.
They dismounted periodically to run and warm up their feet and to get
past unridable obstacles. At least that's the urban legend.

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.

It's not the wrong tool, Chalo, for riding like a cyclo-crosser. Riding
it like a mountain bike would be a misuse of the tool, the fault of the
operator and not the tool.

Of course, I just ride off road on my road bikes and don't even own
anything with fat knobby tires.

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).

I see 2" tires on 26" wheels often at cyclo-cross races, since the UCI
rules are not in effect here in the US at the vast majority of events.

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.

That's because it's not mountain biking. Different activity, different
tool.

MTBs are used frequently in 'cross races. They are at a disadvantage on
a properly designed 'cross course which is very different from a
mountain bike course. They're just too slow on pavement.

plenty of people doing very fast TT's on "road" bikes