Article: How Far is Too Far to Bike to Work

[Tim Kelley]

https://mobilitylab.org/2017/02/27/how-far-bike-work/

What’s the consensus?

Topic

[lordofthemark]

@SolarBikeCar 156526 wrote:

I commute 15 miles. electric assist made that distance possible for me. Without electric assist my limit would be about 9 miles. I have a commute budget of 45 minutes which at 9 miles can be done at an average speed of 13mph. To get 15 miles in 45 minutes requires average speed of 20mph , which is not possible without motor assist. At 20mph biking is just as fast as car commuting and more predictable as it is not subject to traffic problems.

I think its great that the ELF makes it possible for more people to go faster, in more conditions. I do not expect to ever be able to keep up an average speed of 20MPH, and while I am fine with my 50 minute to an hour commute these days, I could see going E assist or even ELF someday when I get older.

I would however, at that point, map out a suitable commute road on the roads. With the ability to go 20 MPH, even uphills (?) I should be able to find that without too much difficulty, I think. I guess I could no longer use the 14th Street Bridge to get into DC though – I would have to use the Memorial Bridge instead.

[Crickey7]

Meh. Just sell the house and move closer.

[Steve O]

@ian74 156485 wrote:

There is no distance too far! There’s just never enough time, and sometimes you get tired.

I have a friend who lives in Berkeley, CA. He used to commute to Stanford every day. He took BART to Union City (1 hour) and then rode his bike 20 miles across the Dumbarton Bridge to Stanford Research Park. He would then reverse in the evenings.
At least it was pretty flat

[Steve O]

@Harry Meatmotor 156538 wrote:

That is not true.

In theory.
In reality, averaging 20 mph on a 15-mile commute is only possible if virtually all of it is on a grade-separated trail. If even 3-4 miles of the commute is on streets or any kind of urban infrastructure, there is no way. Look at dcv’s commutes. He is a truly badass, very fast rider and he averages, over 19 miles, 17ish on his fastest days.
Exactly once I averaged 20mph+ on my 8-mile commute from near 7 corners to 13th & L NW DC, which I rode hundreds of times. There was a truly miraculous, once-every-thousand-years confluence of green lights the entire ride (AND I exhibited utter disregard for other trail users, behavior of which I am now ashamed). Averaging 20 mph day in and day out is just not possible except in the rarest of circumstances.

[SolarBikeCar]

@Harry Meatmotor 156538 wrote:

That is not true.

I don’t see you proving it false in real life.

I suppose one could build a device that reduced the drag at 25mph down to a few hundred watts but it would be uncomfortable to ride and not have room for luggage. If one’s commute had hills (say 2% over 15 miles) then the physics changes to also needing power to increase the potential energy of the device (about 160 additional watts for a 200# device).

Bottom line: if you have a device that can travel for 15 miles at an average speed of 20mph (i.e. a cruise speed of 25mph) over a 2% grade with a human input of less than 250 watts… I’ll buy it.

[drevil]

@SolarBikeCar 156568 wrote:

I don’t see you proving it false in real life.

I suppose one could build a device that reduced the drag at 25mph down to a few hundred watts but it would be uncomfortable to ride and not have room for luggage. If one’s commute had hills (say 2% over 15 miles) then the physics changes to also needing power to increase the potential energy of the device (about 160 additional watts for a 200# device).

Bottom line: if you have a device that can travel for 15 miles at an average speed of 20mph (i.e. a cruise speed of 25mph) over a 2% grade with a human input of less than 250 watts… I’ll buy it.

[ATTACH=CONFIG]14184[/ATTACH]

[lordofthemark]

@Steve O 156567 wrote:

In theory.
In reality, averaging 20 mph on a 15-mile commute is only possible if virtually all of it is on a grade-separated trail. If even 3-4 miles of the commute is on streets or any kind of urban infrastructure, there is no way. Look at dcv’s commutes. He is a truly badass, very fast rider and he averages, over 19 miles, 17ish on his fastest days.
Exactly once I averaged 20mph+ on my 8-mile commute from near 7 corners to 13th & L NW DC, which I rode hundreds of times. There was a truly miraculous, once-every-thousand-years confluence of green lights the entire ride (AND I exhibited utter disregard for other trail users, behavior of which I am now ashamed). Averaging 20 mph day in and day out is just not possible except in the rarest of circumstances.

1. ELF’s are not, AFAIK, exempt from red lights (though at least it should be easier accelerating from a standing start on them?). 2. ELF’s are fully legal on the street, and their use there is not controversial.

So I am pretty sure this particular sub discussion about ELFs (not the whole discussion of commute distance) is about trails. I think mostly about the W&OD.

[SolarBikeCar]

A trained cyclist can produce about 400 watts of mechanical power for an hour or more, but adults of good average fitness average between 50 and 150 watts for an hour of vigorous exercise. A healthy well-fed laborer over the course of an 8-hour work shift can sustain an average output of about 75 watts.
(from Wikipedia)

[Harry Meatmotor]

@SolarBikeCar 156568 wrote:

I don’t see you proving it false in real life.

I’m not going to link to my Strava activities, but I prove it false quite often.

@SolarBikeCar 156573 wrote:

A trained cyclist can produce about 400 watts of mechanical power for an hour or more, but adults of good average fitness average between 50 and 150 watts for an hour of vigorous exercise. A healthy well-fed laborer over the course of an 8-hour work shift can sustain an average output of about 75 watts.
(from Wikipedia)

Sweet! This’ll turn into a “What’s your FTP???” thread!!!!

FWIW averaging 20mph, while weighing roughly 200lbs (bike, backpack, and rider) requires ~260w-280w on varied but relatively flat terrain (for me). I’d guess that equates to about 2.9-3.1w/Kg.

Far less than “A trained cyclist” producing “400 watts”. If that Wikipedia stuff is pointing to FTP with that 400w number, I’d say that’s looking at PRO-level wattage numbers. Not comparable to the situation you brought up.

Regardless, throwing crap out there like “THE ONLY WAY TO AVERAGE 20MPH IS RIDE IN CAR-SHAPED BICYCLE WITH MOTORS” is pure bull shit. Ride more. Lose weight. Then, ride some more. You’ll go faster.

@SolarBikeCar 156573 wrote:

Bottom line: if you have a device that can travel for 15 miles at an average speed of 20mph (i.e. a cruise speed of 25mph) over a 2% grade with a human input of less than 250 watts… I’ll buy it.

I’ll sell you my commuter bike! It’s got gears! and purple things! But no motors

But, I second the notion to buy a house closer to your place of employment. And stop riding a car-shaped bike with motors on the MUPs.

[cvcalhoun]

@SolarBikeCar 156568 wrote:

Bottom line: if you have a device that can travel for 15 miles at an average speed of 20mph (i.e. a cruise speed of 25mph) over a 2% grade with a human input of less than 250 watts… I’ll buy it.

Yep, I have one. It’s called a car.

Given the last part of your forum name, you recognize that what you have is at the very least a bike/car hybrid. You’ve admitted that you have altered the basic ELF so that its top speed without human assistance is over 20 mph without human assistance, so it is no longer a bicycle under federal law.

You could have come here and said, “I have this wonderful vehicle. It’s a car that operates partly on human power, so I can get my exercise while using it. It uses far less fuel than a regular car. But it provides protection against the weather. It can maintain an average speed greater than a bicycle (indeed, high enough to keep up with traffic on most local roads), making it practical for longer commutes.” And people would have lauded you as using an environmentally superior alternative to a regular car.

But instead, you keep trying to tell us it is a bicycle, even though it clearly isn’t. And to use it on bike trails, which are not set up for a vehicle that wide, and that impossible to see through. And then you are surprised and offended when people respond in a negative manner.

[SolarBikeCar]

@Harry Meatmotor 156578 wrote:

I’m not going to link to my Strava activities, but I prove it false quite often.
I’ll sell you my commuter bike! It’s got gears! and purple things! But no motors

…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.

[SolarBikeCar]

@cvcalhoun 156580 wrote:

Yep, I have one. It’s called a car.

TL;DR. A car that goes 20mph on 250watts. Really? Show me!

[cvcalhoun]

@SolarBikeCar 156590 wrote:

TL;DR. A car that goes 20mph on 250watts. Really? Show me!

You said “human input” of less than 250 watts. My car requires human input of less than 250 watts.

[lordofthemark]

@SolarBikeCar 156589 wrote:

…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.

Okay I am not the person putting out the most wattage around here, ride a commuter bike, and I am liking my 10 miles (though I skip days – but fewer each year) but then its my exercise, and often the high point of my day.

I am pretty sure e assist would help me with a longer commute – 15 for sure. OTOH since I would be avoiding riding it on trails, that might offset that for me – though it would probably open up a lot more roads to me (but still not limited access highways, and perhaps not 45MPH arterials for more than very short sections). I would explore routing options further, but since that is neither a personal need (see above) nor a pressing policy/advocacy need, I will refrain.

[SolarBikeCar]

@cvcalhoun 156592 wrote:

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.

[Author]

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