Search found 683 matches

by donn
Oct 27 2020 10:37am
Forum: EBike General Discussion
Topic: Slowest wind direct drive hub motor(s) available?
Replies: 63
Views: 1691

Re: Slowest wind direct drive hub motor(s) available?

People manage pretty well on a range of bicycle wheel sizes. If you want to get into the weeds on efficiency, there's also the wind resistance. Rolling and wind resistance are nowhere near as significant as the issue that comes up with a hub motor's RPM range, but even there, it isn't important enou...
by donn
Oct 27 2020 9:12am
Forum: EBike General Discussion
Topic: How practical is 72v (or 60v) for a street legal direct drive set-up meant for climbing and sub 28 mph speed?
Replies: 124
Views: 3197

Re: How practical is 72v (or 60v) for a street legal direct drive set-up meant for climbing and sub 28 mph speed?

Yeah, I sure don't mean to claim that we all need exercise cycling, per se, and certainly not at the performance-oriented levels that the lycra crowd gets into. It may be more about that basal metabolism, vs. the truly sedentary lifestyle. I'd like to say it's just walking when you can, bicycling if...
by donn
Oct 26 2020 9:38pm
Forum: EBike General Discussion
Topic: How practical is 72v (or 60v) for a street legal direct drive set-up meant for climbing and sub 28 mph speed?
Replies: 124
Views: 3197

Re: How practical is 72v (or 60v) for a street legal direct drive set-up meant for climbing and sub 28 mph speed?

A fallacy that defies the laws of physics unless the energy expended for transportation also replaces exercise that would be done if not cycling. I tried to look it up, but all I could find was energy expenditure for cycling clearly written for someone who want to maximize it - and in the better so...
by donn
Oct 26 2020 8:00pm
Forum: EBike General Discussion
Topic: How practical is 72v (or 60v) for a street legal direct drive set-up meant for climbing and sub 28 mph speed?
Replies: 124
Views: 3197

Re: How practical is 72v (or 60v) for a street legal direct drive set-up meant for climbing and sub 28 mph speed?

Using the same reasoning as yours we can state that a man commuting 20 miles on a bicycle, does consume more resources than another one doing the same ride on an ebike, simply because the transformation of food into energy is the least efficient energy production means. If we would still use horses...
by donn
Oct 26 2020 4:47pm
Forum: EBike General Discussion
Topic: How practical is 72v (or 60v) for a street legal direct drive set-up meant for climbing and sub 28 mph speed?
Replies: 124
Views: 3197

Re: How practical is 72v (or 60v) for a street legal direct drive set-up meant for climbing and sub 28 mph speed?

OK, well, new page, original topic has gotten very old ... It seems to me that one can dismiss the moral superiority of the bicycle only if one sees no problem with inefficient use of resources in transportation. To get there without some loss of moral standing, one would have to believe that there ...
by donn
Oct 26 2020 10:10am
Forum: EBike General Discussion
Topic: How practical is 72v (or 60v) for a street legal direct drive set-up meant for climbing and sub 28 mph speed?
Replies: 124
Views: 3197

Re: How practical is 72v (or 60v) for a street legal direct drive set-up meant for climbing and sub 28 mph speed?

I think you will occasionally see "moral equivalent" used in a rather broad sense, where it's simply about a fundamental distinction that may matter to people. I don't care to take on the motorcycle vs. bicycle question here myself, but indeed it may matter to people.
by donn
Oct 25 2020 11:46pm
Forum: EBike Technical
Topic: rear wheel hub vs geared motor question
Replies: 10
Views: 412

Re: rear wheel hub vs geared motor question

So here's a technical question of principle, relating to two objectives that came up here: cruise control, and electric freewheeling. Is it possible that the same controller won't do a good job on both? I have cruise control on my Infineon clone (and really like it, use it all the time.) With this c...
by donn
Oct 25 2020 10:30am
Forum: EBike General Discussion
Topic: New to this
Replies: 17
Views: 713

Re: New to this

dogman dan wrote:
Oct 24 2020 7:35am
Hard searching could turn up a left hand throttle, but they are rare.
$20 at electricscooterparts.com, if you have 7/8" bars.
by donn
Oct 25 2020 2:17am
Forum: EBike General Discussion
Topic: How practical is 72v (or 60v) for a street legal direct drive set-up meant for climbing and sub 28 mph speed?
Replies: 124
Views: 3197

Re: How practical is 72v (or 60v) for a street legal direct drive set-up meant for climbing and sub 28 mph speed?

Yes! It certainly doesn't make sense to use the existing real life controllers that are modeled in the motor simulator, because what would that prove!?
by donn
Oct 20 2020 11:49pm
Forum: EBike Technical
Topic: raising voltage to maximize regen. braking?
Replies: 55
Views: 2064

Re: raising voltage to maximize regen. braking?

I'm not saying the per cell charge current decreases, just saying the total pack charge current decreases. 4P at 10A is 2.5A/cell, so a 2P pack would only be able to do 5A total. Sure - but 5A at 72V, vs 10A at 36V, isn't it? = 360W. The actual voltage from the hub is something else, transformed by...
by donn
Oct 20 2020 2:37pm
Forum: EBike Build Threads
Topic: ++Giant Glory DH build + GMAC + PhaseRunner
Replies: 20
Views: 996

Re: ++Giant Glory DH build + GMAC + PhaseRunner

Would any experts please tell me whether I can get 65kmh max on the 8T GMAC and 53kmh max on the 10T GMAC according to Grin's simulation above ? Which one should I go for: 8T for speed or 10T for better stability ? I'm trying to finish this new Giant Glory build for my son's birthday within this No...
by donn
Oct 20 2020 10:12am
Forum: EBike Technical
Topic: raising voltage to maximize regen. braking?
Replies: 55
Views: 2064

Re: raising voltage to maximize regen. braking?

Re : cells' chemistry ... As long as we do it properly and use it within limit, li-ion can be very dependable. Countless of Li-Ion packs have been in usages for decades and there have been very minor issues (per lithium batteries capita) in the scale of ppm or ppb. ... Though LiFePO4 might be safer...
by donn
Oct 20 2020 1:12am
Forum: EBike General Discussion
Topic: New to this
Replies: 17
Views: 713

Re: New to this

Yeah, "crank forward" is one term for that. I wouldn't much care for it as a bicycle, but for a scooter it could do OK. A real recumbent will have lower wind resistance - and if it has the same kind of handlebar stem, the fork would lean even farther back, but the majority of designs are l...
by donn
Oct 19 2020 11:50pm
Forum: EBike Technical
Topic: raising voltage to maximize regen. braking?
Replies: 55
Views: 2064

Re: raising voltage to maximize regen. braking?

Goatman , following on donn's post, said, if it is the A123 at 4p for 10ah, it can handle 40amps. the bms is the issue. My reply: this is very interesting! Perhaps for my braking needs I should stick with LiFePo chemistry! Not really ... I use LiFePO4 myself, but it's essentially the same as LiCo h...
by donn
Oct 19 2020 9:49am
Forum: EBike General Discussion
Topic: How practical is 72v (or 60v) for a street legal direct drive set-up meant for climbing and sub 28 mph speed?
Replies: 124
Views: 3197

Re: How practical is 72v (or 60v) for a street legal direct drive set-up meant for climbing and sub 28 mph speed?

I dont think 72v can be street legal on a bicycle. Over 60v it is considered dangerous high voltage and need to meet harder safety regulations. That's interesting! naturally, questions of legality can be answered accurately only in terms of a particular jurisdiction, but it's interesting that even ...
by donn
Oct 12 2020 10:41am
Forum: EBike Technical
Topic: raising voltage to maximize regen. braking?
Replies: 55
Views: 2064

Re: raising voltage to maximize regen. braking?

Correct - thanks for pointing it out. I had 13s in my mind, which is 54.6V max volt Just nitpicking here, but note that he has a LiFePO4 battery. I don't know details, but A123 26650 cells are rated for 10A charge, so I've been assuming a 1P configuration like mine. Of course it doesn't matter what...
by donn
Oct 10 2020 3:47pm
Forum: EBike Technical
Topic: raising voltage to maximize regen. braking?
Replies: 55
Views: 2064

Re: raising voltage to maximize regen. braking?

Do you have experimental data to support this ? In my experience adding more P cells works better than a longer serie Sure, but I think you're talking about something else. The original was, I think, about available regenerative braking force given a 10A charge limit. If you can put in only 10A at ...
by donn
Oct 10 2020 11:17am
Forum: EBike General Discussion
Topic: Can an unlocked controller be a bad thing?
Replies: 11
Views: 382

Re: Can an unlocked controller be a bad thing?

If a controller can be SET at a maximum limit, does that mean it can safely handle that setting as well? As a matter of principle, this question seems to boil down to "can a safe limit be determined"? If I've designed a controller, will I be able to know exactly how much current it can ta...
by donn
Oct 08 2020 5:04pm
Forum: EBike Technical
Topic: Analysis of regen on an ebike
Replies: 151
Views: 55072

Re: Analysis of regen on an ebike

In this case it doesn't seem to matter that it starts high - I don't see any braking in the story, so no regen, right?
by donn
Oct 06 2020 2:58pm
Forum: EBike Technical
Topic: raising voltage to maximize regen. braking?
Replies: 55
Views: 2064

Re: raising voltage to maximize regen. braking?

you can increase regen amps to 40amps. Can he? Just casually looking around for guidance on this, all I see is, a lot of avoiding the question. My battery's official maximum charge current is 10A. I'm confident that I could exceed that by a few amps in brief regen braking, and it wouldn't burst int...
by donn
Oct 06 2020 9:57am
Forum: EBike Technical
Topic: raising voltage to maximize regen. braking?
Replies: 55
Views: 2064

Re: raising voltage to maximize regen. braking?

No. Torque is a function of intensity, not voltage. For a given motor, and at the same power level, higher voltage = higher top speed but lower torque. Not sure about regen, but I guess it's similar. I'd be interested to know, about regen. Is the following reasonable as far as it goes? He sets the ...
by donn
Oct 05 2020 8:23pm
Forum: EBike Technical
Topic: raising voltage to maximize regen. braking?
Replies: 55
Views: 2064

Re: raising voltage to maximize regen. braking?

It sounds reasonable to me in principle, that a higher voltage battery could tolerate more regen current, but I'm no expert. I'm just wondering if when you get everything working right with your present setup, it will provide plenty of regen braking.
by donn
Oct 03 2020 8:58pm
Forum: EBike General Discussion
Topic: E-Trike
Replies: 15
Views: 342

Re: E-Trike

Right, mid drive - viewtopic.php?t=95363
by donn
Oct 02 2020 6:36pm
Forum: EBike General Discussion
Topic: US National Parks Electric Bicycle Policy Memorandum
Replies: 11
Views: 630

US National Parks Electric Bicycle Policy Memorandum

https://www.nps.gov/subjects/biking/ebike-regulations.htm A couple selected items. First, in the unintended humor category: The definition in the Memorandum refers to the definition of “electric bicycle” in the Consumer Product Safety Act (15 U.S.C. 2085), which limits the power of the motor to les...
by donn
Oct 02 2020 11:40am
Forum: EBike Technical
Topic: Kelly Controllers Configuration Program - a Definitive Translation
Replies: 28
Views: 11555

Re: Kelly Controllers Configuration Program - a Definitive Translation

[x] Cruise: No info available, presumably cruise control. Actually the Cruise function is not activated by the switch outside. If you hold the throttle at a certain position for more than 4-5s, the controller will get into Cruise control. When you turn on the brake switch or turn the throttle and r...