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Thread: Article: How Far is Too Far to Bike to Work

  1. #61
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    Quote Originally Posted by cvcalhoun View Post
    You said "human input" of less than 250 watts. My car requires human input of less than 250 watts.
    Implicit in the conversation is that we are talking about human as the sole energy input since your objection was to e-assist. Methinks you knew that.

  2. #62
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    Quote Originally Posted by SolarBikeCar View Post
    ...and a person of average power output (say 100 watts) will not be able to move your commuter bike at an average speed of 20 mph. As you admit it takes more than 250watts on a road bike to achieve that speed.

    This topic is about commute lengths and the point I'm making is that math and physics predicts a sweet spot somewhere short of 10 miles and that it can be stretched with electric assist to about 15.
    You were asking how to get an average speed of 20mph for 45 minutes, no?

    That estimated 260-280 watts @ 20mph is on a 27lb commuter bike. That's also only about 10% more effort than your target of "human input of less than 250 watts".

    My proposal: Lose weight, ride more, get stronger. Cost = $0.

    Your proposal: Spend upwards of $7,000 on a car-shaped pseudo-bike with motors.

    One of these proposals might be physically healthier and provoke less spite from your fellow trail users.

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  4. #63
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    Quote Originally Posted by SolarBikeCar View Post
    Implicit in the conversation is that we are talking about human as the sole energy input since your objection was to e-assist. Methinks you knew that.
    On the contrary. It was you who said the advantage of the ELF was that it allowed you to get to work in less time than an ordinary bicycle, using less than 250 watts of human input. If you count the motor, your vehicle requires more than 250 watts. So implicit in your statement is that we are not talking about vehicles that have human as the sole energy input, and that in measuring the watts, we're counting only those provided by the human. By that measure, a car fulfills the requirements--the human provides less than 250 watts.

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  6. #64
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    here is a model of power requirements for the given scenarios. Focus on the black line and the right scale which has the power requirements at speed for a 2% grade.
    That's 500 watts to go 20mph with a 220 lb gross vehicle weight. To get average speed of 20 I need to go about 25 on the straight-aways which increases the power requirements to 800 watts.

    Click image for larger version. 

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    Last edited by SolarBikeCar; 03-08-2017 at 01:51 PM.

  7. #65
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    Quote Originally Posted by SolarBikeCar View Post
    here is a model of power requirements for the given scenarios. Focus on the black line and the right scale which has the power requirements at speed for a 2% grade.
    That's 500 watts to go 20mph with a 220 lb gross vehicle weight. To get average speed of 20 I need to go about 25 on the straight-aways which increases the power requirements to 800 watts.

    Click image for larger version. 

Name:	Power.jpg 
Views:	60 
Size:	70.9 KB 
ID:	14186
    Not modeled; real: Lose weight + get stronger = average speed of 20mph. Simple!

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  9. #66
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    Quote Originally Posted by Harry Meatmotor View Post
    Not modeled; real: Lose weight + get stronger = average speed of 20mph. Simple!
    this model (which matches my real world experiences) proves that you underestimated the power or overestimate the speed and thus are not giving a true picture of what is required to commute 15 miles in 45 minutes over a 2% grade. One has to pay to lift the weight over the grade and you have to fight wind drag and saying a magical incantation doesn't allow one to defy physics.

  10. #67
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    Quote Originally Posted by SolarBikeCar View Post
    this model (which matches my real world experiences) proves that you underestimated the power or overestimate the speed and thus are not giving a true picture of what is required to commute 15 miles in 45 minutes over a 2% grade. One has to pay to lift the weight over the grade and you have to fight wind drag and saying a magical incantation doesn't allow one to defy physics.
    Do you have a power meter on a bike, other than your car-shaped pseudo bike? How much do you weigh?

  11. #68
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    Quote Originally Posted by Harry Meatmotor View Post
    Do you have a power meter on a bike, other than your car-shaped pseudo bike? How much do you weigh?
    Dude, you're feeding the troll. Every post from this turkey turns into an argument. Just do what I've done; this is what I see when he posts:

    This message is hidden because SolarBikeCar is on your ignore list.

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  13. #69
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    Let him be a troll, and ignore him. He's picking arguments to fight, ignoring the ones that he can't. It's not advancing the thread, and serves no point other than to get people mad.

  14. #70
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    I guess the issue is why is one required to accept as predetermined a set of variables, namely 15 miles in 45 minutes over a 2% grade (which would apply in only one direction in any event). Why is it that none of those can vary? Some people drive part of the way. Some people take longer than 45 minutes. People often say things are not possible because they've claimed certain variables are not variable, that they are fixed. Only one of those is fixed, the 2% grade.

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