Asymmetric Commute!

[OffGrid]

I didn't realize until I got going (reading this forum and considering my prime motivations for connecting here) that I DO have a possible bicycle commute option.

My commute is (only) 15 miles but is 2000 ft elevation change (up to work, down from work).   I will unlikely ever have the combination of time/energy/stamina to ride *to* work on a bicycle, but coming home is a literal *breeze*.   I sometimes drive (coast) my 86 honda CRX HE home with only one 1-mile startup and a 1-mile boost in the middle and sadly a 100yard finish! under power.   I get about 60mpg if I do this daily for several tanks.   I normally top out at 50mpg with this car driven carefully.   My sense of conservation of energy and system efficiencies suggests to me that most of my extra 10mpg is that I'm only driving 50 mph uphill (It will do 80, but redlined in 3rd/of5 gear) and a variable 30-70 most of the way down (actually braking part of the way!).

I could probably commute one-way via bicycle just by getting a ride daily uphill, but an electric assist might easily make the difference in convenience in time for the stretches where I would have to pedal hard for 30 + minutes to keep up speed/time.

If I link in my windmill system (especially to modular 18V cordless tool packs) I wonder how much power 15 (-2) miles of downhill riding could generate to augment?

A good rule of thumb might be charging the batteries at the max of the hub/regenerative-controller/charging for (most of) the time on the road...  If I simply exchange 2 miles of powering for 4miles of charging, I get 8 miles of pure charging...   at 16-24 mph (I'm not a thrill seeker and the regenerative braking might even slow me down that much on the steeps!) I'd gain net charge on the road for 20-30 minutes.

So... NOT MUCH unless I ganged a lot of batteries together in-parallel (another good reason for using the cordless)...
The extra weight would increase my potential energy from the top of the hill, at the expense of my carpool-buddy hauling the extra weight up the hill in the morning (probably not that much).

more on hybrid-power considerations in a separate post.


- OffGrid

[myelectricbike]

This will do it for me for awhile. (Don't have my voice recognition up and running right now...)

You are limited to 3 wheels to remain a legal ebike not in need of tags but you can add a trailer with any number of wheels and load it up with batteries to power your ride. Just be prepared to leave it somewhere if it breaks down, especially at the bottom of your hill. Good luck with all of your ideas. Hope at least one of them gets done.

[OffGrid]

> his will do it for me for awhile. (Don't have my voice recognition up and running right now...)
>
> ou are limited to 3 wheels to remain a legal ebike not in need of tags but you can add a trailer with any number of
> wheels and load it up with batteries to power your ride. Just be prepared to leave it somewhere if it breaks down,
> especially at the bottom of your hill. Good luck with all of your ideas. Hope at least one of them gets done.

Thanks for the engagement...

Yes, trailered battery units are appealing.  Since I *live* at the bottom of my hill, breaking down there isn't quite the problem it would be otherwise.

Yes, I know I'm a bit prolific here in my ideas... and don't expect any *one* person to wade through it all and engage meaningfully... but maybe it will be a good catalyst for a few conversations with a variety of people with their own related ideas (and more importantly, experiences).

I have not even rigged an electric bike yet, and even if I do, it is highly unlikely that I will ever actually try to ride the bugger home from work, even with regenerative braking... the traffic conditions are rarely suitable for a bicycle anyway.

I only implement 1/100th of my schemes which with the number of schemes I go through is still a sizeable number...  just not very many of the ones I consider/contemplate/discuss.

-OffTopic

[Dave]

Although I live in the flatlands, I'm in kinda the same boat as you; my commute to work isn't terribly far, but I generally don't bike it because there are no shower facilities at work, and I don't care to subject the people I work with to my sweaty self after the ride there. I bought a hub motor to make the ride to work less strenuous, and will do the return trip with leg power for the exercise I'm needing.

In your situation, it'd be a matter of first figuring out how much battery power you'd need to make it up the hill. I bumped into a calculator a while back on another forum that may help in that (link).

Here's a story about a guy who did the Cycling To The Sun race in Hawaii on an ebike; that race covers about 35 miles and ends at the top of a 10k mountain. It didn't seem to require an enormous amount of battery power to get him to the top, but he didn't use a hub motor for the job; he's of the opinion that hub motors aren't up to the task. Perhaps not for that kind of climb, but shouldn't be a problem for the rest of us.

[Dalecv]

You could put together a bike that would make the commute up the hill with little or no pedaling. You would be spending a fair amount on batteries for the amp hour capacity needed and your commute time would be in the one hour range on the way to work.

[OffGrid]

Thanks dale and dave for the calculator link and the rule-of-thumb.

My inputs/calculation with Dave's calculator corroborates Dales estimate of 1 hour.

The result suggests that a 750W system (20 A @ 36 V) with a 20 AH capacity should do the trick (if I can stand a 1 hour ride to work, which I generally can't, especially in the winter.

I am surprised that this would even be in the range of possibility... it sounds like I could strap a 90 AH battery from my truck to my bicycle (ignoring 12V vs 36V) and race up the hill at an average of 16 mph.

My Ryobi 18V batteries are rated at 2000mAH so I guess I'd need 10 to get to work.... but sadly I suspect I'd have to ride at about 5 mph regeneratively for 3 hours to recharge them, they just don't take charge as fast as they give it up!

This all sounds a little optimistic for me, but maybe I just don't appreciate the power/weight ratio of electric bikes.

In any case, I'd opt for the ride up the hill and bicycle down... putting 20-30 minutes of charge into whatever batteries I was carrying....

Hmmm...