Likes Likes:  74
Dislikes Dislikes:  1
ELITE ELITE:  0
Page 9 of 11 FirstFirst ... 7891011 LastLast
Results 81 to 90 of 110

Thread: Fine for riding e-bikes on trails in DC?

  1. #81
    Join Date
    Feb 2010
    Location
    Leesburg, VA
    Posts
    1,435
    Post Thanks / Like

    Default

    Quote Originally Posted by mstone View Post
    I think that current production e-bikes are fine on most of our current infrastructure. I'm pretty sure that most of our trails can handle people puttering along at low speeds on ebikes, and nobody really cares/will press the issue. I'm also pretty sure that most of our trails can't deal with larger numbers of higher speed electric vehicles. Every time we go around on this it comes back to what we have now basically works (with some winks & nods) but that the limiting factor is basically technology: it's extremely likely that within the next 10 years, advancements in batteries will make it easy to have a crazy, overpowered electric vehicle on a trail. I haven't seen a workable proposal to deal with that reality which seems more effective than just officially banning motorized vehicles and hoping for good discretion in enforcement. I really hate that idea, but I also see no possibility that we're going to have cops on the W&OD with dynamometers, checking for legal horsepower. (Or somehow checking for speed governors.) The only real winning scenario I see is for on-street infrastructure to improve to the point that the people on electric bikes don't have a desire to use the MUPs and we can keep the no-motor rule without having to wink at all.
    This sums up my thoughts pretty succinctly. Things work fine now, because e-bikes are expensive and (in general) fairly limited in the power they provide. But its hard to look at the rate of progression in the tech and not think that they will continue to get both more powerful and cheaper. I mean, you can get some pretty ridiculous e-bikes today if you have the inclination (and a lot of money). See: http://www.stealthelectricbikesusa.c...tric-bike.html. Where will things be in 5 years? 10?

    I'm right there with e-bike advocates in seeing the advantages of the tech. I'd much, much, much rather people hop on an e-bike for the commute than get in the mercedes. More people on two wheels is good for cycling in general. I'm more mixed when it comes to allowing motorized vehicles on trails like the Mt Vernon, Custis or CCT. I get why people want it, I get that in most cases it probably won't be an issue, but I think its a huge can of wormy conflict waiting to happen.

    Its easy to say that we just set a limit (x watts, or x speed before assist cuts off, or whatever) but the fact is that such limits are basically so impossible to enforce that I'm not sure there is even a point in having them. Its not like you can look at a bike and see how large the motor is, or know where the assist cuts off. I feel like you either allow them on the MUP (which means allowing all of them) or you just say no motors at all. I hate the idea of leaving it up to police discretion (which is where we are now; its technically not allowed, but as long as you aren't being a dick you won't be hassled) but I'm not sure what the better solution is.

  2. #82
    Join Date
    Jun 2011
    Posts
    4,342
    Post Thanks / Like

    Default

    Quote Originally Posted by DismalScientist View Post
    Why are overpowered e-bikes bad on MUPs, yet appropriate on on-street, presumably bicycle, infrastructure?
    Because of the issue of shared pedestrian space. I'm significantly less worried about bicycle+electricbike conflicts because the speed differential will still be lower, and the behavioral patterns will be similar.

    And the enforcement problem goes the other way: I think it's just as unrealistic to try to enforce a ban on electric bikes in on-street infrastructure as it is to try to keep MUPs safe through speed & horsepower limits.

  3. #83
    Join Date
    Feb 2013
    Posts
    407
    Post Thanks / Like

    Default

    Quote Originally Posted by AFHokie View Post
    Btw, how much torque does a typical e-bike have? A buddy of mine (and not a big guy either) had an old motorcycle that was so anemic it topped out around 45mph on anything more than a gentle uphill grade. I could be wrong, but I don't expect to see e-bikes roaring up the Custis through Rossyln at 25+mph in the near future.
    I have a reasonably nice e-bike setup. It's a 500Watt continuous (peak 800Watts over a short hill) motor driven by a 36Volt battery. It offers a strong assist up to 20mph on flats (~22mph when fully charged and ~18mph when approaching empty). Fully charged it can haul me up Capitol Hill at ~17mph putting out just over 800Watts, which isn't nearly enough to show up on the first few pages of Strava's leaderboards. Also, a full charge lasts ~20miles of hard use and I've had a friend borrow it for a road ride and stretch a charge for over 40miles with judicious use of the throttle.

    You can also drive the same motor with a 48Volt battery that will provide a max speed of 25mph. This is the most powerful option that's readily commercially available. However the same ~10lb battery will only have a ~10mile range if used at those speeds.

    This is a big reason that I don't foresee overpowered e-bikes becoming a serious problem. The tradeoffs required to provide an incremental amount of top speed are pretty steep. I've seen the battery market focusing on providing increased range and lower weight over slight speed boosts, and I see that being the industry's continued focus even as technology improves. The 60Volt batteries needed to break the 30mph threshold currently weigh well over 30lbs and have terrible range.

  4. #84
    dasgeh's Avatar
    dasgeh is offline Queen of Family Biking & All Things Kidical
    Join Date
    Aug 2011
    Posts
    5,788
    Post Thanks / Like

    Default

    Quote Originally Posted by acl View Post
    Pedestrians. Toddlers on trikes and trianing wheels. Dogs being walked.
    But those are all endangered by any bike going fast. Ebikes (that meet the federal definition or something close to it -- weight should also probably be a factor too) aren't any more dangerous for them.

  5. #85
    Join Date
    Jun 2011
    Posts
    4,342
    Post Thanks / Like

    Default

    Bikes aren't the driver for battery technology, cars are. There's been as much technological development in the last 15 years as there was in the previous 50, and the pace seems to be accelerating. What you're pointing out is exactly what I'm talking about: there's no reason that a tricked out bike that today generates 500W won't be 1000W in a decade, at roughly the same size/weight, based on developments which were made in labs 5 years ago and will almost certainly be commercialized due to pressures in the auto industry in another 5. As far as the voltage, all lithium ion cells generate about 3-4V and are simply wired in series to increase that to the desired level. If the number of ebikes increases its very hard to imagine that there won't be a significant market for third party replacements to drive the technology. Don't look at what's available on the market from reputable vendors, look at what hobbyists are stringing together for crazy amounts of money--that's what people will be buying at walmart in a few years.

    Edit to add: put it a different way--10 years ago you'd have an electric bike with either a lead acid or NiMH battery; consider the weight and power from each of those, and extrapolate.
    Last edited by mstone; 10-28-2014 at 03:58 PM.

  6. #86
    dasgeh's Avatar
    dasgeh is offline Queen of Family Biking & All Things Kidical
    Join Date
    Aug 2011
    Posts
    5,788
    Post Thanks / Like

    Default

    Quote Originally Posted by jabberwocky View Post
    Its easy to say that we just set a limit (x watts, or x speed before assist cuts off, or whatever) but the fact is that such limits are basically so impossible to enforce that I'm not sure there is even a point in having them. Its not like you can look at a bike and see how large the motor is, or know where the assist cuts off. I feel like you either allow them on the MUP (which means allowing all of them) or you just say no motors at all. I hate the idea of leaving it up to police discretion (which is where we are now; its technically not allowed, but as long as you aren't being a dick you won't be hassled) but I'm not sure what the better solution is.
    This goes back to my proposal: just regulate the actual behavior you have a problem with on the trail, regardless of what kind of bike they are on.

    But even enforcement of a motor limit isn't actually that hard because all of that information is in the material that comes with the bike. Even if bikes with more power become commercially available, it's still going to be a tiny minority that is willing to put these things together on their own. So we just look at the materials from the manufacturer.

    As to that tiny minority, are you really saying that family bikes should be forced on the streets and onto our current insufficient on-street bike infrastructure now because a few people are able to construct bikes that can go really fast?

  7. #87
    dasgeh's Avatar
    dasgeh is offline Queen of Family Biking & All Things Kidical
    Join Date
    Aug 2011
    Posts
    5,788
    Post Thanks / Like

    Default

    Quote Originally Posted by mstone View Post
    Bikes aren't the driver for battery technology, cars are. There's been as much technological development in the last 15 years as there was in the previous 50, and the pace seems to be accelerating. What you're pointing out is exactly what I'm talking about: there's no reason that a tricked out bike that today generates 500W won't be 1000W in a decade, at roughly the same size/weight, based on developments which were made in labs 5 years ago and will almost certainly be commercialized due to pressures in the auto industry in another 5. As far as the voltage, all lithium ion cells generate about 3-4V and are simply wired in series to increase that to the desired level. If the number of ebikes increases its very hard to imagine that there won't be a significant market for third party replacements to drive the technology. Don't look at what's available on the market from reputable vendors, look at what hobbyists are stringing together for crazy amounts of money--that's what people will be buying at walmart in a few years.
    So you want to force family bikes and others who can't bike on regular bikes onto the street now because of your vision of the future? Why not have the law that applies now reflect the reality of today and ban tomorrow the scary things developed then? If you're worried about government inertia, make the current ban-lifting temporary.

  8. #88
    Join Date
    Feb 2010
    Location
    Leesburg, VA
    Posts
    1,435
    Post Thanks / Like

    Default

    Quote Originally Posted by 83(b) View Post
    This is a big reason that I don't foresee overpowered e-bikes becoming a serious problem. The tradeoffs required to provide an incremental amount of top speed are pretty steep. I've seen the battery market focusing on providing increased range and lower weight over slight speed boosts, and I see that being the industry's continued focus even as technology improves. The 60Volt batteries needed to break the 30mph threshold currently weigh well over 30lbs and have terrible range.
    I guess it comes down to how much you think the tech will progress in the near future. I lurk on electric-sphere a fair bit (I actually built an electric longboard earlier this year), and I see the crazy stuff people are building. As you noted, really the only thing holding things back are the batteries, but a tremendous amount of resources are going into battery development (mostly for the automotive industry, but it all trickles down). People are building some powerful bikes now, using off the shelf components. Some people even buy battery packs for hybrid cars to use (the nissan leaf packs are apparently popular for this). Its just a question of where things will go and how fast we will get there.

    My electric longboard was built for under a grand, and will go ~23mph for 10-15 miles. Thats a vehicle that weighs less than 20 pounds, that I built myself, using essentially off the shelf RC car parts.

    The thing with e-bike discussions is its hard to limit yourself to whats available now, because the tech is progressing so fast (electric propulsion in general, not e-bikes in particular). Its pretty awesome, actually.

  9. #89
    lordofthemark's Avatar
    lordofthemark is offline I really need to log off the internet and go for a ride.
    Join Date
    Jun 2012
    Location
    The forgotten corner of Alexandria, VA
    Posts
    3,411
    Post Thanks / Like

    Default

    Is the issue speed, or is HP important independent of speed, because of potential fast acceleration?

  10. #90
    Join Date
    Jun 2011
    Posts
    4,342
    Post Thanks / Like

    Default

    Quote Originally Posted by dasgeh View Post
    So you want to force family bikes and others who can't bike on regular bikes onto the street now because of your vision of the future? Why not have the law that applies now reflect the reality of today and ban tomorrow the scary things developed then? If you're worried about government inertia, make the current ban-lifting temporary.
    No, I want to keep the current situation where people just use reasonable ebikes on the trail in such a way that most people don't even notice, and nobody really cares.

    Quote Originally Posted by dasgeh View Post
    This goes back to my proposal: just regulate the actual behavior you have a problem with on the trail, regardless of what kind of bike they are on.
    We're never going to see that level of enforcement. We might get to a point where the police will look for a person with repeat complaints and tell him to get the motorized vehicle off the trail, but we're not going to have a permanent presence that penalizes bad behavior as it happens.

    But even enforcement of a motor limit isn't actually that hard because all of that information is in the material that comes with the bike.
    So a cop pulls someone over because he suspects they're running an overpowered bike, and the process is that they whip out the manual? And the cop just says "ok, you've got a manual"? For a scheme like that to work you'd end up with a vehicle registration scheme just like you have for cars to enforce all of the motor vehicle regulations (which would make the price advantage of ebikes vanish, and put things on a bad course for cycling generally).

    Even if bikes with more power become commercially available, it's still going to be a tiny minority that is willing to put these things together on their own. So we just look at the materials from the manufacturer.
    I do not believe there's any chance that will reflect the state of affairs in a decade, as improved batteries get cheaper and more widely available. That is really the only limitation at this point. I don't expect that this will be something that involves a soldering iron, but rather the purchase of a widget off amazon. You seem to think that the current limits are set in stone, but what you can buy today at a store would have been either a fantasy or a hell of an impressive DIY project a decade ago.

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •