6 ms·

The part about braking just isn't true. Sure, there is a stopping limit for any braked device - a bicycle cannot stop any faster than it's wheels can hold fric

by brc 14y ago

The part about braking just isn't true. Sure, there is a stopping limit for any braked device - a bicycle cannot stop any faster than it's wheels can hold friction. I've crashed bikes several times from emergency stops (bikes don't have abs). You can stop any type of board-device and stay on, as long as the friction between the board and the rider is greater than the wheels and the road. You don't automatically flip off the end of a board while braking any more than you flip over the handlebars on a bike - that's because you adjust your position when braking, and more so when braking hard.

tomflack 14y ago
"A bicycle cannot stop any faster than it's wheels can hold friction." Nothing can stop faster than "it's wheels can hold friction". But on a bicycle when you brake hard then momentum is transferred on to the front wheel, which is typically ahead of where the bulk of the weight (the rider) is situated. "You can stop any type of board-device and stay on, as long as the friction between the board and the rider is greater than the wheels and the road." On a skateboard, the front wheel is MUCH closer to the center and the centre of gravity is MUCH higher. You'll be flung off if you stop as fast as a bicycle with properly maintained brakes can safely.
- johnyzee 14y ago
  It's really not that difficult - you shift your weight all the way back, flex the rear knee into a very low stance with the front leg 'pushing back' against the deceleration. With proper technique you can brake almost as well as a bike.
  - tomflack 14y ago
    Simply incorrect that you can get bike like braking safely, even using the described technique. Edit: I really want to prove this, but the only way I can think of to do it is you buy one of these for $1200, I buy a bike for $1200 and we spend $1200 in airfares to meet somewhere and try it out. Perhaps someone with physics qualifications can weigh in?
    - johnyzee 14y ago
      I have been riding a board like this in urban traffic for a while, so I am speaking from experience.
      - 001sky 14y ago
        Motorcycle>bicycle>skateboard. There is simply more inertial mass on a Moto, which allows you do use the front brake to its full potentail without pitching a faceplant. That and the suspension absorbs some energy. Also, the rider position is usually COG to the rear. On a bike, your body position on drop bars puts you more COG forward, steeper head angle, more levered over the front friction patch (tire/road). The bike is light, suspension if any not as robust, its prette easy to stop a 20lb bike vs a 250-500lb moto, and for you to fly off. You are like a pole vaulter at 60 deg vs 45deg on the stick (not precise, just directional) Normal skate is same thing, its light, close to ground, The board has a low COG. The rider a much higher one. The board has no suspension. So, it can stop on a dime if it meets and object that makes one wheel "not round". You are like a pole vaulter at 90 degrees. It it possible to ride like a ninja, super low and crouched to the back and de-weight at precisely the right time to go over XYZ obstacle. Maybe. But the issue really is one of probabilities. At what stage do you not foresee the obstacle? And heaven forbid an hazard that is only slightly more complex, say, 10-20 meters of sand or grit on the tarmac, that you cant just skip over. That is a very normal type of defect to urban road surfaces. Ther is a reason they have "street sweepers" and alternate side parking and all of that.
        brc 14y ago
        I think the problem here is that people are conflating an enforced stop - hitting a rock - with a normal braking stop, and even then with an emergency stop. If the issue is - is an electric skateboard more dangerous than a bike? well, then of course it is. You're less visible, less stable, and have less braking ability and much smaller wheels. But that's not to say you can't safely brake a skateboard without throwing yourself off the front. Like any device - motorised or not - it's up to the operator to control their speed for the conditions.

by brc 14y ago

tomflack 14y ago

"A bicycle cannot stop any faster than it's wheels can hold friction." Nothing can stop faster than "it's wheels can hold friction". But on a bicycle when you brake hard then momentum is transferred on to the front wheel, which is typically ahead of where the bulk of the weight (the rider) is situated. "You can stop any type of board-device and stay on, as long as the friction between the board and the rider is greater than the wheels and the road." On a skateboard, the front wheel is MUCH closer to the center and the centre of gravity is MUCH higher. You'll be flung off if you stop as fast as a bicycle with properly maintained brakes can safely.

johnyzee 14y ago
It's really not that difficult - you shift your weight all the way back, flex the rear knee into a very low stance with the front leg 'pushing back' against the deceleration. With proper technique you can brake almost as well as a bike.
- tomflack 14y ago
  Simply incorrect that you can get bike like braking safely, even using the described technique. Edit: I really want to prove this, but the only way I can think of to do it is you buy one of these for $1200, I buy a bike for $1200 and we spend $1200 in airfares to meet somewhere and try it out. Perhaps someone with physics qualifications can weigh in?
  - johnyzee 14y ago
    I have been riding a board like this in urban traffic for a while, so I am speaking from experience.
    - 001sky 14y ago
      Motorcycle>bicycle>skateboard. There is simply more inertial mass on a Moto, which allows you do use the front brake to its full potentail without pitching a faceplant. That and the suspension absorbs some energy. Also, the rider position is usually COG to the rear. On a bike, your body position on drop bars puts you more COG forward, steeper head angle, more levered over the front friction patch (tire/road). The bike is light, suspension if any not as robust, its prette easy to stop a 20lb bike vs a 250-500lb moto, and for you to fly off. You are like a pole vaulter at 60 deg vs 45deg on the stick (not precise, just directional) Normal skate is same thing, its light, close to ground, The board has a low COG. The rider a much higher one. The board has no suspension. So, it can stop on a dime if it meets and object that makes one wheel "not round". You are like a pole vaulter at 90 degrees. It it possible to ride like a ninja, super low and crouched to the back and de-weight at precisely the right time to go over XYZ obstacle. Maybe. But the issue really is one of probabilities. At what stage do you not foresee the obstacle? And heaven forbid an hazard that is only slightly more complex, say, 10-20 meters of sand or grit on the tarmac, that you cant just skip over. That is a very normal type of defect to urban road surfaces. Ther is a reason they have "street sweepers" and alternate side parking and all of that.
      - brc 14y ago
        I think the problem here is that people are conflating an enforced stop - hitting a rock - with a normal braking stop, and even then with an emergency stop. If the issue is - is an electric skateboard more dangerous than a bike? well, then of course it is. You're less visible, less stable, and have less braking ability and much smaller wheels. But that's not to say you can't safely brake a skateboard without throwing yourself off the front. Like any device - motorised or not - it's up to the operator to control their speed for the conditions.