[disclaimer: first post, no e-bike yet, researching and reading up] [English not my first language]
Interesting discussion, with both sides bringing up valid points well argued. It's definitely a hot topic and a fine line to walk. There is no right or wrong in my opinion, it really depends on where you stand on a lot of issues. Public area civil behaviour, personal responsibility, understanding that holding back technological advances is pointless, regulation versus common sense.
So either you trust in the common sense of the trail riders out there, which makes regulation unnecessary. Or you want to regulate "the dumb" away. I personally have little hope for individual restraint, and courtesy or sympathy towards other users in the public space . Maybe I'm too pessimistic, but the general attitude of the current Go-Pro generation is individualistic and entitled. Only the personal thrill is important and all else has to give way for the enjoyment of the individual.
Also, people tend not to be cautious or properly evaluate risk and hazard in the moment, until someone gets hurt. It's a shame to always have to learn after the facts, after it's too late.
In Europe there's really almost no electric powered MTBs around. So the issue is fairly non existent. But I'm sure they will be regulated once they start becoming a common sight.
My thoughts on a few things discussed here.
- damaging trails. I don't believe eMTBs are any more harmful or damaging to trails than regular MTBs are. I don't know about the trails in the US, but usually they are either hard packed dirt, or rocky, without any vegetation or plants to begin with. I don't think you can do much damage there, and if you do, you'd be doing the same kind of damage on non-eMTBs. I certainly hope people stay ON the trails and don't go ripping up plants and wildlife by going off the trails. But I would like to think that MTBers have some respect for the environment.
- bruised little ego's of the human powered cyclers: honestly who gives a ****. That's not even worth discussing. If riders are that thin skinned and whiney they'd better find another hobby. Why would you even care? I usually ride alone (non-eMTB), so it's me against the ride, on my tempo, with my skills. How does someone cycling up the hill with less effort leaving you in the dust, ruin or alter YOUR OWN experience? I just don't get it. You're there, with your equipment that you chose, knowing full well your and your bikes limitations. (difference of speed as a safety issue is something else)
- SPEED: Downhill it will make no difference. Gravity >> electric assistance. Specially on heavier bikes. So that's more or less a wash between non-eMTB and eMTB, no discernible difference there. This leaves uphill and level riding where a difference will be notable. Then it comes down to common sense again. Will you use the electric engine to extend your rides? Save some energy for other parts of the ride you might enjoy more? (downhill for example) Will you be going at similar speeds of a well trained pro-MTB'er? (1-1,25 x speed, just using some e-powered watts to help you out), then I see no issue. If you're basically taking a home built electric motocross bike into typical MTB playing grounds, riding 3x the average normal speed, then obviously somethings gotta give.
Again, if you're responsible enough to slow down when approaching kids/hikers/people walking their dogs/horses, then I see absolutely no problem. But I'm sure a few won't because they have a video rolling, and all it takes is a few bad apples to ruin things for everyone. That's how it always goes. Let's hope it doesn't come to that.
As long as the overall speed and riding profile of an eMTB is not that much different from a human powered MTB, no one will care. You'd be hard pressed to see the difference at a glance to be honest, especially with the modern well integrated designs of today (except for the noise perhaps).
- Another very good argument you read often is this: eMTBs will allow people who for whatever reason could not MTB anymore (age, distance on the trails, lowered physical shape, injuries) to pick up a bike and enjoy MTB'ing again, or allow them to keep riding with their buddies. Who can possibly be against that? That's perhaps the single most important argument to allow eMTBs on trails, ever, defeating all others. It's just a matter of community feel and solidarity.
- Regulation: where would you draw the line? The spectrum of e-bikes is so wide and fluid and the technologies so diverse, it's impossible to define a cut-off point. Before it used to be easy: Human powered (with the speeds that go with that) and engine powered (motorcycles).
Also, there's no point in regulating something you can not enforce. How will you possibly check this? Put people at every entry point of a particular forrest? Chase mountain bikers around the tracks?
Is 500Watt too much? 750? 1000? 3000? Today you can build something more like a 200cc motocross bike in a MTB frame with pedals just for good measure, is that still a bicycle? I do however share some concern about the latter. Big power in frames and forks that can't handle that load is going to lead to accidents (loosing control/crashes) both for yourself and others.
As a closer, take look at this (not a MTB-trail, but precisely the sort of behaviour and bad apples that will ruin it for everyone).
Watch the first four minutes. Those are lanes for recreational usage. Kids, families with strollers, runners, commuters, ... NOT 75 kph machines. That machine for me is a motorcycle on skinny tires. The fact that he can make it past the gates at the beginning of those paths means nothing anymore and doesn't justify him being there. I can technically squeeze my motorcycle through there too, but no one would think that's an appropriate place to be with a motorcycle.
And if I would be on those paths, smelling the roses as it were, walking a dog, I would definitely not appreciate what this guy is doing. Imagine he startles a dog and runs into a leash or something. That thing is heavy and can do some serious damage when run into a runner at 75kph, like breaking a lot of bones kinda damage.