Knowing some of the young people these days, it might be a good idea to keep most of thaem as far away as possible from our National Parks. As a former mountain biker, I can tell you that most riders off-trail are completely oblivious to the hikers who also share the same space. This new rule is a grab by the bicycle manufacturers (most of whom aren't even American anymore) to facilitate what they hope are higher sales. Our government and our National Parks as your marketing agent. Classy.

How about if they put a tax on mountain bikes to pay for upkeep?

It all depends on motorized access.  If the bikers can drive in, bike awhile and then drive out, they'll do a bunch of damage.

If not, not...

This is just a ruse and we've taken the bait.  

It's not about the mountain bikes, it's about the four-wheel drives, ATV's and snowmobiles . . . motorized access.  They've invited the mountain bikers to the party in hopes that we'll draw some of the fire.  

Personally, I am fine with keeping the National Parks off limits.  Why ride in Yosemite when the Sierra National Forest is open and right next door?  

This is crazy, we cyclists should say "no thanks" and back away from the impact/access canard to emphasize the point that motorized access is wrong.  

Preserve and protect our pristine National Parks, ride elsewhere.  

I love spending time in our national parks..one of the most rewarding things we have in this country ...I'd like to see our parks used as a place to LIVE...not solely as a museum..

Personally I don't mountain bike much at all..and I certainly think users would need boundaries and guidance...but I would propose that the parks do allow mountain bikes.

One thing I do find when I visit the parks is that there is always a high level of attention by the park rangers to keep things in line with the policies that make the parks enjoyable and well preserved for all.

There are always going to be those that visit the parks that don't treat it as they should ...but let's face it that's not the mountain bikes fault.   It's as likely to happen with folks coming in with campers, or backpacks on foot etc etc.  

It would take perhaps a DIFFERENT TYPE of maintenace than the foregoing require, but all incoming traffic, even on foot requires maintenance.  

I have an optimistic hope that the more often people have the ability to act in harmony with our/their environments ..the more of the planet we will want to become 'park like'...ie  wouldn't it be nice if we treated our own cities and homes, in fact the entire planet with the same sanctity we bestow on the National Parks??... perhaps experiences that can be had in our parks will extend an opportunity for all, mountain bikers or not..to learn to stretch the boundaries of what we treat with an eye toward sustainability and preservation.

TT

not trails.  Bikes are just another industrial machine, are not at all natural, diminish the nature experience for those of us disturbed by them and, most important, disturb the animals who live there and cause erosion.

Biking instead of driving is great and everyone should at least be strongly encouraged to do so.  But if you want to spend time in nature, spend it naturally, not on a bike.  Learn to use your own feet!

Let's see...a bike tire is about an inch wide and about 3 inches (at most) long has contact with the ground.   The weight of the bike plus the person is Person + 50 lbs extra approximately.

The hiker wears two boots that are about a foot long and 4 inches wide, so 48 sq. in. of surface area.

The bike is continuous, so in 10 ft of trail, it would be 120 sq. in.  trod upon with Person+50 lbs of force for each 6 sq. in. (two tires).

The person would leave about 10 foot prints or 480 sq. in. of damage with Person lbs of force on each foot print.

A bike moves faster than a person, so the person's presence in nature is much less...less disturbance to wildlife.

You could make a case the bike would create less damage.

Great example of faulty reductionist thinking.  The facts and statistics you mention are all irrelevant.

The fact is that bikes cause erosion on trails with grades.  They also disturb wildlife and, when they ride off the trails for various reasons, such as avoiding hikers, they kill or harm plants.

You are, however, correct to imply that walking in boots is unnatural and possibly ecologically harmful, as opposed to walking barefoot.

My experience in UK national parks, in the Lake District, the Peaks and the North Yorkshire Park, is that bikes do damage paths. By creating a thin ditch in which water collects they lead to stream flows in heavy rain which then drain peat and earth from the path. Not only that, sdaly, bikers do not tend to have the same respect for nature that the walkers do. I hate to say this but that is my experience over many years.

Wolverine writes:

You are, however, correct to imply that walking in boots is unnatural and possibly ecologically harmful, as opposed to walking barefoot.

Right, and having super strong metal knives come out of your knuckles, that's natural...

Keep your eye on the ball, y'all.  Boot soles vs knobby tires isn't the real debate on trail damage, it's all about the power.  More power means more damage and a human engine does not have that much.  

If you know any cyclists that train with power meters, 250 watts is riding hard.  That's about 1/3 horsepower.  

To put that in perspective, a 700cc quad ATV will have over 40 hp on tap.  

I've seen a quad do more damage in a single ride than a decade of non-motorized access.  Of course it's possible to ride them responsibly too, but my point is that this hiker vs biker thing is a distraction.  The rule change also allows motors, right?  

Claiming mountain bikes are in the same league as motorized access is pure BS.  Motorized access does at least an order of magnitude more trail damage, never mind the noise made is "shared" with everyone within at least a 1/4 mile.  And when compared to horses, mountain bikes have significantly less trail impact.  I have over 30 years of hiking and backpacking experience in the Cascades and I just can't see where opening some more trails to mountain bikes would create a serious problem.  For example, it is my experience that the bikers with trail ettiquette problems don't have the fitness or stamina to ride very far into the mountains.  All riders I have met in the few remote areas open to mountain bikes have been without exception respectful and courteous.  They are not red state motorheads but instead young, fit, and motivated people who get involved in public lands protection issues.  It would be a mistake to discourage this group.