Frequently Asked Questions about Mountain Biking
Michael Vandeman, Ph.D.
March 5, 2004
1. Why do people mountain bike?
a. They say that using a bike allows them to get much farther, in the same
amount of time, than they can by walking. They also maintain constant pressure
on land managers, to open more and more trails to bikes. Of course, all of these
trails are already open to them, if they choose to walk. They also frequently
claim that closing trails to bikes "excludes" them from the parks. This could
only be true if they were unable to walk. Of course, they are able to walk.
There's nothing inherently wrong with bicycling instead of walking; we all like
to save energy, when it's appropriate. Use of a bicycle to replace automobile
use is obviously beneficial. However, by the same token, replacing hiking with
mountain biking is obviously not beneficial.
b. They are interested in the quantity of nature they can see, rather than the
quality of their experience. While riding a bike, especially over terrain as
rough as a trail, one has to be constantly paying attention to not crashing.
That make it almost impossible to notice much else. By contrast, a hiker feels
the ground, hears all the sounds and smells all the odors of nature and can stop
instantly, if he/she finds something interesting. The brain thrives on
stimulation. A biker has to travel several times as far as a hiker, to get the
same stimulation as a hiker. (And, by the same token, motorcyclists have to
travel several times as far as a bicyclist, and an auto user several times as
far as a motorcyclist, since they are enclosed in a metal box.)
c. They are interested in thrills. Riding a bike on a trail, especially a trail
containing many obstacles, or a trail one is not familiar with, is very
challenging. (But if mountain biking is the high point of your week, as it seems
to be for many mountain bikers, you must be leading a pretty dull life, off of
the bike!)
d. They are interested in building mountain biking skills and competing with
other mountain bikers. The thrill of racing drives people to spend more money on
their bike, and ride it harder and more often. Racing, up to and including the
Olympics, drives a lot of mountain biking. Of course, it is also extremely
harmful to the parks and natural areas that are used for practice! It is hard to
think of any other (legal) use of public lands, other than hunting, that is as
harmful as mountain biking.
2. What is driving the sport of mountain biking? Besides the attraction for
participants, manufacturers and retailers of mountain bikes and mountain biking
accessories, as well as "adventure" travel guides, make a lot of money from
promoting mountain biking. Even some auto manufacturers (e.g. Subaru) promote
and sponsor mountain biking, and try to use its popularity to sell more cars.
The tourism industry also promotes mountain biking, among other attractions.
3. What harm does mountain biking do?
a. Most obvious is the acceleration of erosion. Knobby tires rip into the soil,
loosening it and allowing rain to wash it away. They also create V-shaped
grooves that make walking difficult or even dangerous. The mechanical advantage
given by the gears and ball bearings allow a mountain biker to travel several
times as fast as a hiker. Given their increased weight (rider plus bike), this
results in vastly increased momentum, and hence much greater horizontal
(shearing) forces on the soil. (Witness the skid marks from stops, starts, and
turns.) According to Newton, every action has an equal and opposite reaction.
Mountain bikes were built much stronger than other bikes, so that they could
withstand the greater forces they were subject to on rough trails. These same
forces, therefore, are being applied to the trails! To give a definite number,
the winner of a 20-mile race here in Briones Regional Park averaged 13 MPH (the
speed limit is 15 MPH -- where were the park rangers?).
b. A hiker must be very careful not to accidentally step on small animals and
plants on the trail. For a mountain biker, it is almost impossible to avoid
killing countless animals and plants on and under the trail. They have to pay
attention to controlling the bike, and can't afford to look carefully at what is
on the trail, especially when travelling fast. And even if they happen to see,
for example, a snake, it is hard for them to stop in time to avoid killing it. A
hiker, when crossing a creek, will try to avoid getting wet, by crossing on
stepping stones or logs. Mountain bikers, on the other hand, simply ride right
through the creek bed, crushing any animals or plants that happen to be there.
Mountain biking magazines are full of photos of mountain bikers throwing up
spray, as they barrel through creeks. Not only do bikes destroy animals and
plants as they ride across streams, they ride through streams stirring up
sediment. The sediment in the water interferes with the oxygen uptake by aquatic
life, for example, killing fish- and frog eggs. Young fish, insects, amphibians,
and aquatic microorganisms are extremely sensitive to sediment in water.
c. Bikes also allow people to travel several times as far as a hiker. This
translates into several times the impacts, both on the trail and on the wildlife
(to say nothing of the other trail users). Existing parklands are already
inadequate to protect the wildlife that live there. When they are crisscrossed
by mountain bikers and legal or illegal trails, their habitat becomes even more
inadequate. Mountain bikers frequently advertise rides of 20-50 miles or more.
Have you ever tried to walk that far in a day? In other words, allowing bikes in
a park greatly increases human presence in that park and drives wildlife further
from the resources that they need to survive, including water, food, and mates.
d. Due to their width and speed, bikes can't safely pass each other on narrow
trails. Therefore, policies that permit mountain biking also result in more
habitat destruction, as trails are widened by bikers (or by hikers and
equestrians jumping out of their way).
e. Knobby mountain bike tires are ideal for carrying mud, and consequently
exotic plants, fungi, and other organisms from place to place, resulting in the
spread of exotic invasive species, such as weeds and Sudden Oak Death.
f. Mountain biking is driving the very young and old off of the trails and hence
out of the parks. Even able-bodied hikers and equestrians fear for their safety,
and don't enjoy sharing the trails with bikes. (The mountain bikers claim that
they are simply being selfish and "unwilling to share", but actually they have
no problem sharing trails with mountain bikers; it is only their bikes that are
a problem!)
g. Mountain bikes, which are obviously built to go anywhere, teach children and
anyone else who sees them that the rough treatment of nature is acceptable. This
undoubtedly has a negative effect on people's treatment of nature.
h. In order to mitigate bike-caused erosion, park managers have been resorting
to extreme measures -- even in some cases putting a plastic matrix or other
exotic material under the trail (e.g. in Pleasanton Ridge Regional Preserve,
near Pleasanton, California)! It's hard to imagine that this will have a
beneficial effect on the park and its wildlife….
i. Allowing mountain bikes in a park greatly increases the damage to the trails,
damage from "bootleg" (illegally created) trails, and the problems of conflicts
between trail users, and hence the cost of maintaining the park. Considering how
tight park budgets are, we can't afford the extra costs of policing, and
repairing the damage from, mountain biking.
4. Mountain bikers claim that their sport has no greater environmental impact
than hiking. Is that true? If you read the "studies" that make that claim, you
find that they don't really compare the impacts of hiking and mountain biking,
but only the impacts per foot. If, for a moment, we assume that the studies are
correct in their having equivalent impacts per foot, it would still follow that
mountain biking has far greater impact per person, since mountain bikers
typically travel so much farther than hikers. Besides overlooking distances
travelled, those "studies" almost all ignore impacts on wildlife. And they don't
study mountain biking under normal conditions -- only at a very slow speed.
Actually, the comparison with hiking is irrelevant. It would only be relevant if
we planned to allow only one of the two, and were considering which of the two
is more harmful. In fact, no one is considering banning hiking. We are only
considering adding mountain biking. Therefore, the only relevant question is,
"Is mountain biking harmful"? (Of course, it is!) There is only one truly
scientific study that I know of that compares the impacts of hiking and
mountain biking. It found that mountain biking has a greater impact on elk than
hiking (Wisdom, M. J., H. K. Preisler, N. J. Cimon, B. K. Johnson. 2004. Effects
of Off-Road Recreation on Mule Deer and Elk. Transactions of the North American
Wildlife and Natural Resource Conference 69: in press. Wisdom et al. 2).
5. Where should mountain biking allowed? A couple of role models for wildlife
protection are Yosemite National Park and East Bay Municipal Utility District
(in Alameda and Contra Costa counties, California). They both restrict bicycles
to paved roads, where they can't do much harm. Somehow bicyclists have managed
to enjoy their sport for over a hundred years, without riding off-road.
6. What should the policy be on trails? Closed to bikes, unless marked open.
Signs that say "No Bikes" are quickly and repeatedly ripped out of the ground by
mountain bikers.
7. Isn't it discriminatory to allow hikers and equestrians on trails, but not
mountain bikers? Mountain bikers love to say this, apparently because they think
it will gain them some sympathy. The truth is that mountain bikers have exactly
the same access to trails that everyone else has! It is only their bikes that
are banned. If mountain bikers were really being discriminated against, they
could easily go to court to gain access. However … they already have access to
every trail in the world!
8. Don't I have a right to mountain bike on all public lands? I am a taxpayer!
The public has the right, through its elected representatives, to restrict how
land is used. A federal court has already ruled that there is no right to
mountain bike. It is a privilege, and any land manager who gives a good reason
(such as safety or protecting the environment) can keep bikes off of trails (see
http://home.pacbell.net/mjvande/mtb10.htm).
9. Don't mountain bikers do some good things, like trail construction and trail
maintenance? Trail construction destroys wildlife habitat both directly (by
killing plants and animals) and indirectly (by reducing the size of the
intervening "islands" of habitat). Moreover, mountain bikers favor trails that
are "twisty" (sinuous), bumpy, and full of obstacles that provide thrills for
mountain bikers. Such designs increase habitat destruction (by lengthening the
trail) and make the trails less useful for hikers and equestrians. Trail
maintenance sounds good, until you realize that it would hardly be necessary, if
bikes weren't allowed there. The mountain bikers are the main reason why trail
maintenance is necessary! Trails used only by hikers require hardly any
maintenance. Therefore, admitting bicycles to a park greatly increases its cost
of maintenance. Nothing is really "free", including trail construction and
maintenance. (How does the saying go? "Beware of Trojans bearing gifts"?)
10. But don't mountain bikers provide added safety, by being able to quickly
summon help in the event of an emergency? I would rather trust in a cell phone,
than a speeding mountain biker. Besides, natural areas are already one of the
safest places you can be. In over 50 years of hiking and backpacking, I have
never witnessed any situation requiring emergency aid. Most people go to natural
areas partly for solitude. If we wanted to be around large, fast-moving pieces
of machinery, we would stay in the city!
===
I am working on creating wildlife habitat that is off-limits to
humans ("pure habitat"😉. Want to help? (I spent the previous 8
years fighting auto dependence and road construction.)