Does More Power Sometimes Decrease Rider Satisfaction?

General Discussion about electric bicycles.

Does More Power Sometimes Decrease Rider Satisfaction?

Postby Ken Taylor » Mon Dec 17, 2012 1:40 am

With power assist it seems at first, that more is always better but I suspect that as with our reaction to artificial humans, the level of satisfaction from power suffers an uncanny valley. With 200 W I might win the Tour de France but with 500 W I've got a gutless motorbike. The analysis which led to this suspicion is at http://blog.urremote.com/2012/12/what-w ... -when.html . If true, the ideal ebike power is pretty low.

On endless sphere I found some opinions that seemed similar, but nothing direct. Do experienced ebike riders always get more satisfaction from more power?
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby amberwolf » Mon Dec 17, 2012 1:45 am

It entirely depends on the rider and their needs, as well as their purpose for the bike.
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby chvidgov.bc.ca » Mon Dec 17, 2012 1:54 am

I've experienced this when I recently put a "Cute" motor on a nice light aluminum framed roadbike,a much smaller motor than my other 9C, BPM, Crystalyte etc, on my other bikes. I've been very happy with the very bikelike experience, enough power to keep my speed up on local hills, light weight and great freewheeling, and quiet. I like it! I can still cruise in the mid 20mph range, and being a strong pedaller, I don't really need the extra power of the larger motors on a lightweight bike. I imagine I get under 10watt hr per mile efficiencies too. Definitely worth a try, for a more bikelike experience. And you can use a smaller pack too - I've gone to just a 10amphr Headway pack at 48volts, which is quite adequate for the small motor so as not to be stressed. It's great for what it is, but I wouldn't do a big tour with a lot of gear on it. With a bit of chronic tendonitis, the lighter weights are easier on my body too. And the motors are dead simple to install, and hardly need torque arms, although I used them anyway, and cheap to replace. So yes, I would agree with your premise in some cases. On the other hand...the 9C on the trike with 40Ahr of dual Pings also rocks hard....it all depends on the situation. I think its worth having different bike aimed for each purpose, whether zippy urban commuting, or long-range gear hauling
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby miuan » Mon Dec 17, 2012 2:07 am

I agree the sensation of a gutless motorbike makes e-bike a crappy experience at 500W. That's why most folks here have much more power :)

If you intend to travel at 30 to 35 mph at times due to traffic, there's no way 250W is gonna cut it. If getting to work with no sweat, just light pedaling is your goal, forget the 250W machine getting you up serious hills. I've tried that when my big motor had broken halls. There's barely satisfaction in riding like that.

There are sections of my commute where I do use no more than 250W, so the combined power of 400W gives me a cruising speed of about 20mph. However that's only when I can avoid traffic altogether.
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby Jeremy Harris » Mon Dec 17, 2012 3:11 am

I started out with a fair bit of power, but find that the ebike I like best, and ride most, is the light one with the low power motor. The reasons aren't that straightforward, I think.

The light bike is much nicer to ride than the heavier bikes, which is certainly one plus point. The power assist and throttle control is also less aggressive and needs far less conscious effort to manage. If I'm just riding around the city in traffic, then I don't want to have to worry about accidentally popping a wheelie or getting wheel spin off the lights, I want to concentrate on the nutters around me in their steel boxes that are trying to kill me much of the time.

On the other hand, if I'm going for a blast around some of the nearby almost traffic free lanes, then the low powered bike isn't that much fun, so I tend to take the bigger bike.

I guess is all depends where you ride and why you're doing it. Cycling around the city doing errands seems easier to me if I use the light, low powered bike. Riding for fun on empty roads seems nicer with a bit more power.
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby biohazardman » Mon Dec 17, 2012 3:21 am

Ideal for who is the question? I am 60 years old have several disabilities as well Hepatitis-C so I would not ride much at all if it were not for the help. I started out with a 500W DD motor but it would not take the hills as well as I would like and it was heavy. It also would not let me ride much past 12 MPH because of the induced drag of the motor. So thought a 600W geared motor was the answer. Then as you said I turned into a junkie and wanted more power so 48 to 52 to 60 then 66 and finally 72V. I can go up any of the hills around here with minimal effort at 60V but higher voltages mean a few more batteries so a bit better range without all the weight of more AH in parallel. Geared motors are only slightly louder than the DD and after some hundred miles mine is about the same as my old DD motor. This is ideal to me and I only added about 16LBs to my XC bike. Six pounds of that is batteries to get me 15 miles or so down the road at 20MPH with very mild peddling. The experience of riding a 55LB cushy supension bike might not be so ideal to someone else. It's a very personal thing to each of us no way to group us all together.
You on the other hand sound like you want just a bit of assist and a lightweight bike. If you want to pedal you will likely want a small geared unit that freewheels. A rear drive will cut your available gears down to 5-7 depending on the motor. A front unit will not but it can be a serious safety hazard if things get loose or fail. You should be able to put something on your bike and only gain 10 to 12 LBS if you go light. Lightweight lipo or a123s batts are a good thing to keep the weight down and AH up. Another option is a small friction drive setup that you only engage when you want that little extra. Probly the lightest and stealthiest way to go but I doubt it's the longest lasting. Then again it all depends on how you take care of these things as they all have their limitations. Several have built the types of bikes your style of riding might compliment one has already posted. Think about it before you jump in cuz once the addiction starts it hard to resist. :twisted:
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby NeilP » Mon Dec 17, 2012 4:14 am

Ken Taylor wrote:Do experienced ebike riders always get more satisfaction from more power?

:P YES YES YES YES YES!!! :D
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby biohazardman » Mon Dec 17, 2012 4:19 am

I do like NeilP's approach ;^) and did forget to mention that I have a mid-drive build with a 3220 going so will have two or thee times the power I now have on tap. Oh, the addiction is acting up again I need more what?
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby NeilP » Mon Dec 17, 2012 4:37 am

biohazardman wrote: Oh, the addiction is acting up again I need more what?



I think you mean I need more WATTS
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby dogman dan » Mon Dec 17, 2012 7:22 am

A great deal depends on the goals of your ride. As goals change, the mental attitude changes.

I'd love more power on my dirt bike. But since one of the goals is to keep it fairly light, I've limited it's power to medium. 3000w that is :twisted: Funny how that's only medium power these days. :mrgreen: That bike gets pedaled 1/4 mile or less out of a typical 6 mile ride.

But on bikes where the goal is to get long distances, I'm very happy with bikes in the low end of medium. 1000w-2000w. Which I actually run on 500w or less if I really have a long ride in progress.

I still haven't done the superlight bike, but I bet I'd like pedaling one a lot. This would not have a hubmotor, but rather some type of chain or friction drive, and idealy the entire system would weigh less than 5 pounds. Likely less than 200w. The goal would be to preserve a weight of the entire bike less than 30 pounds.

Much depends on your past history. You come from motorcycles, you want more power always. But if you have pedaled 10,000 miles or more, you still like pedaling, even if it's just faux pedaling.

You also have to be able to adjust your mental attitude to different kinds of rides. No such thing as a wrong attitude, but it might be wrong for the bike you are on. If you only have one attitude, then change the bike.
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby MadRhino » Mon Dec 17, 2012 10:16 am

Ken Taylor wrote:...If true, the ideal ebike power is pretty low.

Yep, I think 40HP must be well enough most of the time... That is if the rig is under 80 pounds :mrgreen:
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby liveforphysics » Mon Dec 17, 2012 12:32 pm

Ive always attained the greatest pleasure/fear combo (my favorite emotional cocktail) from adding power, never taking it away.

However, for just creepin around town riding bicycle trails and things, just a few kW assist can make for a really enjoyable fun riding experience.
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby melodious » Mon Dec 17, 2012 4:42 pm

A 500W rated motor and 3 speed switch & pedal assist should satiate most riders' style. If you feel like you want to give more effort (city mode), switch to low/med. On the other hand, a switch to med/high (open road mode) should give you enough power to give your inner speed demon some attention.

That article does have merit. A bike w/motor takes the physicality of the experience away. I'm really hesitant to taint my last true bike into a motorized vehicle. :|
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby dogman dan » Mon Dec 17, 2012 5:05 pm

Yeah, don't do that. Then you'll start thinking like us, that a bike that needs no pedaling is FUN.
I'm just such an old school pedaler, I still enjoy pedaling a lot. But I rode motorcycles a lot too, and DO appreciate my 60 pound one. Sure it's underpowered by motorcycle standards, but it's so wonderfully light for a dirt ride.
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby Samd » Mon Dec 17, 2012 6:46 pm

Does More Power Sometimes Decrease Rider Satisfaction? Sometimes.

I recently downgraded my single speed from 1200W ezee to a 450w q100 front. Nearly took it off altogether. Noodling around the neighbourhood is relaxing at 15kph if you aren't going anywhere. It's the "man's day-spa" of biking. Six pack of beer in the basket up front. You're in the moment all the time.

But sometimes you want to commute for A to B. So you need a fast commuter.

And sometimes you want to go offroad, so a higher powered and agile dual suspension is what you need. Life flashing by on the periphery of your vision.

Just as you shouldn't have one tool in the shed, you can't have one bike for everything. At least that's what I tell my wife. She seems to accept it, but probably wouldn't if I extended the rant to include having a number of women to satisfy different needs also. :mrgreen:

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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby Hyena » Mon Dec 17, 2012 7:24 pm

less-powerful-ebike.jpg
less-powerful-ebike.jpg (93.85 KiB) Viewed 2051 times


:mrgreen:

I agree with what the others have said though - several kw is a blast for zooming around moto-style.
But for bicycle style riding you can certainly get by with much less. 500w might be OK or for a casual ride on the flat but if there's hills and I need to get somewhere (eg commuting to work) 1500w is the minimum for me. If weight isn't the end of the world for you it's alway better to have more power available and just turn it down. Lately I've been trying to get more exercise so have been conciously using less and less throttle and pedalling more. I've shaved 30% off the AH I use getting to work and my trip only takes a few minutes longer and isn't really any more of a chore. At first I did this by limiting the current to 20a in the CA but have since turned it back up to 100a and learned self control. Even if you're happily trundling along it's nice to have a big motor with bulk power on tap if you need to quickly close up a gap or power out of a dicey situation.
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby full-throttle » Mon Dec 17, 2012 8:20 pm

Ken Taylor wrote:Do experienced ebike riders always get more satisfaction from more power?

Not all

< 250W is pathetic. I'd rather have no electric assist than 200W.
> 5kW is motorbike territory. Pedaling not required, so what's the point of having pedals? Either heavy or short ranged.
Somewhere in between still feels like a bicycle. How many? Depends on a person. For me 1~1.5kW is about right.

Same with speed: < 30kph too slow, > 50kph too fast. 35~40 is just right (for a bicycle)

Weight: 20~25kg. Less is even better, but becomes expensive and needs more maintenance.

Range: 30~70km. Modular packs perhaps.
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby aroundqube » Mon Dec 17, 2012 10:18 pm

" Do experienced ebike riders always get more satisfaction from more power?" No, experienced ebike riders always get disatisfaction from not having enough power when the riding situation requires more power. Otherwise, "always" does not apply.
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby Stevil_Knevil » Mon Dec 17, 2012 11:45 pm

When asked about my ~4500W Greyborg, I usually reply, "It weighs 90 pounds. Heavy for an ebike ..light for a motorcycle.."

Total Rider Satisfaction :lol:
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby veloman » Tue Dec 18, 2012 1:43 am

I run 1300watts peak on my Mac hub. Rarely do I feel like I need more power. Mainly because I stick to low volume roads out of pleasure of not wanting to breath exhaust and be around autos. There are some times when I am in traffic and going uphill and yes, it can feel gutless, but the reality is that I am on a bicycle, pedaling. So slowly accelerating through the upper 20s(mph) range on a slight hill is still hauling ass.

1300w on the Mac is plenty of power for going way too fast on bike trails and many side streets. I very rarely use WOT other than during accelerations.

There was a period of time about a year ago where I started out at 600watts peak on my high speed Mac. THAT was a dog. Though if I aero tucked on a fast road, I could hold near 30mph in good conditions. Every month or so I upped the power another 150watts. Each time it was amazing. Then I seemed to settle on 1300watts peak for the mac. For my 9c, I have it at 1800watts peak. I could go higher on my a123 battery, but I feel I have hit the sweet spot. I'm still faster than all mopeds and many scooters.

You just have to remember that you are on a bike. You're not out there to race people. Most of us are out there to supplement pedaling, and/or transport ourselves economicaly, environmentally, avoiding congestion, and just making the bike an amazing tool.

Enough power to me is when i can hold my own in local traffic on all the routes I take.

Though... I do have an interest in a high power build for pure fun / putting my gf on the back (cargo bike).

As for low power - it can be good too. If you have no desire to go more than 15 or 20mph and want to ride like a bicycle at bicycle speeds, then 300watts is enough. That's still a nice supplement to a rider who can't put out more than 200watts on a hill. It's lighter, cheaper, and more efficient.
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby dogman dan » Tue Dec 18, 2012 7:01 am

Yeah, 1500w is a pretty decent compromise power level. It can still be fairly fast, just not so fast to get going. One of my controllers is 72v 20amps. Definitely weak from the stop sign for 72v, but eventually most of my hubmotors will wind up to a 35mph cruise with this controller. So with this setup, you might pedal to 20 mph, then stop.

But a bit nicer generally, is a similar wattage with 48v 30amps. Still right about that butter zone of 1500w. Nicer pickup, so more fun to leave the stop sign, but less speed. 48v 20 amps, is ok too, but not as perky, and less power on a big hill.

Legal issues do rear the head. In most of the USA, over 1000w is not a bike anymore. Lots of us ride illegal homemade motorcyles then. Lucky me, due to a quirk in the NM law, I just barely stay in the moped class with my dirtbike or longtail.
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby John in CR » Tue Dec 18, 2012 8:16 am

How you ride is a matter of personal taste. If we had complete control over power and torque along with swappable battery packs to suit the situation, then only a high power ebike could do it all. As long as your high power needs don't go to the extreme, with ideal placement the extra few kg of motor and controller required isn't enough weight difference to truly matter. It's really only rider input control over our controllers that's missing to be able to have our cake and eat it too, and it's disappointing that so little progress has been made in that regard, since you have to spend big bucks on a controller or build your own for a better solution that still falls short.

The one universal truth we can all probably agree on is that all else equal lighter is better. Otherwise many of us would be on e-motorcycles.

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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby rocwandrer » Tue Dec 18, 2012 1:54 pm

An interesting article you wrote there, Ken. I've enjoyed reading all the replies here as well. I probably don't have much to add to the discussion, having never ridden an e-bike at this point. That wont stop me from providing some input from an alternate perspective :D

I don't really know how much I've ridden pedal only, but I estimate I've worn out more than 50 bicycle chains in my life (many of them in severe service.) I say that to say that I have more than a passing interest in riding bicycles. The vast majority of my riding time is purely recreational, with the destination being the departure point.

My homebuilt recumbent tandem is on the original chain at around 6,000 miles. I have been the captain for almost 100% of those miles. When I ride with a not very fit stoker, or on the rare occasions that I've ridden with a stoker who is FAR more fit than I am, I've observed a relevant phenomenon. Bear with me here... The very fit rider tends to put in about 55-60% of the power. This is regardless of whether the disparity in fitness is tiny or huge. I've tried varying the crank length for cadence preference changes (yes the cadence is the same, but crank length still adjusts for the preference, by feel). When the fit rider puts in the same effort as they would on a single bike, the feeling for the more fit rider is that the bike is slow and sluggish, and the feeling for the less fit rider is that the bike is fast and sluggish.

Why do both the fit and less fit rider think it is hard to accelerate? I think it is because when only one person puts in 50% more effort, it is the same effort as putting in 50% more effort, but the same return as putting in 25% more effort.

Why does the more fit rider feel the bike is slow? The cyclocomputer proves out that two riders of equal fitness are substantially faster together on the recumbent tandem on downhills and flats, and slightly slower uphill, compared to separately on upright bikes. My guess is it is that lack of responsiveness again.

A totally different example: For my snow bike, I have taken individual sprockets from 4 different cassettes, and built a 6 speed cassette with even spacing, 14-36t. Sometimes I want to go just a bit faster, but the shift to the next taller gear puts me enough out of my ideal rpm range that I end up going only a tiny fraction faster for what feels like a lot more effort. Inevitably, I'll pick the lower gear. If the slope rises a bit, I might not even downshift, just put in more effort, because it pays a nominally higher return than cranking the next higher gear on flat does.

I propose that these same issues apply to electric assisted pedal bikes (but NOT necessarily to human assisted or human power backup electric bikes). If the benefit from adding pedal power does not FEEL proportionate to the effort, it is much harder to put in that effort. In the tandem example, I at one point gathered some heart rate data. It was vexing to me that I could easily get to 80% max heart rate and hold there for miles on my road bike, but not on the tandem. I thought there was something about the biomechanics of the recumbent position that was preventing my legs from using the heart and lung capacity. No. It turned out that it was just REALLY hard to force myself to work that much harder for the small dividends it paid with a less fit rider on the back. Riding the tandem alone, I had only marginally more difficulty achieving the heart rate I could get to on the road bike. I think part of that was that the tandem is twice the weight of the road bike, and so there is an incentive to accelerate more slowly and so on.

That all matches with Ken's hypothesis that if there is enough power on tap with the electric assist to make the human contribution feel less critical, or to make the return for extra effort feel too small, it is will psychologically difficult to even acknowledge that there is more in reserve in the human power side's controller.

My tandem experiences also reinforce that too little power might be much less encouraging as well. When riding with a less fit stoker, I tend to only slightly exceed their power output 90% of the time, and only pour on the power pulling away from traffic lights or crossing the top of a steep hill.

This is part of how I decided that I don't really want to experience more than 200-250w of output power from an assist. Experimentally, I am also trying another twist. I decided to try to make it so the assist runs out of gearing well below the speed I can and regularly do achieve unassisted on flat, such that I am only able to use the assist for hill climbing, and for getting through deep snow. We shall see :D
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Build thread:http://endless-sphere.com/forums/viewtopic.php?f=3&t=46287
rocwandrer
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby rocwandrer » Tue Dec 18, 2012 1:58 pm

A voice of dissent from anything I've seen here so far is John Tetz. Back in the 90% he was espousing the virtues of having a 2 hp gas engine friction drives and a tiny fuel tank on extended touring, so as to be able to use the engine to fly up the steep side of mountain passes, but only be carrying a little extra dead weight with no extra drag the rest of the time. I see (http://recumbents.com/wisil/tetz/E-AssistMetric/default.htm) that his perspective has evolved into a philosophy of substantially less power. He talks about 50w of assist in a 5 lb package like it is an excellent long-term plan.
First ebike project - Juggernaut: 30x4.5-ish tires, Q100 rear hub in the front fork, KU63 shaved to ~8 amps, 4.4 Ah 12s LiFePo4
Build thread:http://endless-sphere.com/forums/viewtopic.php?f=3&t=46287
rocwandrer
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Re: Does More Power Sometimes Decrease Rider Satisfaction?

Postby hjns » Tue Dec 18, 2012 2:41 pm

Interesting topic.

For me, it really depends on my desires. For day to day commuting, a high power light motorcycle idea is great. Having a bike less than 35kg with 7-8kW available to me is great. More power is unnecessary for me. Less power would not do it any more.

For riding the trails, I would now prefer a more agile much lighter bike. This is where the balance between power and weight comes into play. I still have to learn to mountainbike properly, and I don't think I am going to learn it with a 35kg heavy weight commuter. For my next project / ebike, I have an old Kona Stinky frame, and I intend to put two small light motors on it. With a small lipo pack, it should allow for a very light bike, think 15kg, and that will help me get up the mountains. Of course, I will loose power. But that outbalances the weight loss gain for me.

And I will still have my high power cromotor to play around with.... :twisted:
Henk


All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find that it was vanity: but the dreamers of the day are dangerous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
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