Bike ergonomics-different for ebikes?

[WoodlandHills]

I am trying to get my wife comfortable on her ebike and so far, her biggest complaint is that the seat is too tall. I have been setting it so that she will not quite be able to fully straighten her leg when seated and at the bottom of the pedal stroke. Since a push bike is set up to maximize the output from a pretty weak motor and her ebike has a pretty decent amount of power, does she really need to be up so high? There was never an issue of standover height at the top-tube, just that it was difficult for her to transition for standing over the bike to standing on the pedals and moving forwards. If she could put a toe down while remaining seated it would be a lot easier for her. And the lower seat will make it easier to swing her leg over too.

I guess, I am asking is if there are any ebike specific guidelines for cockpit fitting? I am thinking of progressively lowering my seat below what would be considered ideal for a non-ebike since I don't ride for exercise and prefer to be on the motor at all times. All I do is twirl my feet at the minimum speed to activate the PAS so I doubt I will have any knee problems!

I also find that I have a much more upright seating position which then requires a softer seat since my back is closer to 90 degrees when not standing. When standing, I have a pair of gigantic platform pedals on 150mm crank arms so my feet are not so far apart front-to-rear, I actually am swapping back and forth between 150mm and 127mm crank arms to see which I prefer. $15 unicycle crank arms rock!!! Once I find what I like best, I will replace the steel test arms with alloy.

 

[Drunkskunk]

Normal bicycle ergonomics are based on a most efficient riding position. the more efficiently you can ride, the less tired you become and the more comfortable you will be.

Ebike ergonomics can be based on comfort first. Since you can get the job done without as much human input, you don't need to be as efficient, and you can ride in the most comfortable seating position.

 

[Leebolectric]

On an E-bike I change my saddle and bars position.
I move the saddle forward on its rails to move my center of gravity forward, which counteracts the wheelie effect.
I also tip the nose of the saddle down a notch, so that under hard acceleration I don't slip off the back as easily.
I find those make my back hurt a lot less, as I don't have to pinch the saddle with my legs and ass.
The forward position is more comfortable for control, and the KOPS isn't as necessary because I pedal with less force with a motor.

I also rotate my handle bars forward slightly on an E-bike...gives me a bit more leverage to pull on and more weight on the front end without a longer stem.
When pedaling without a motor, I keep them rotated to the back for a more relaxed grip and shorter reach to better lift the front end.

I ride 165 cranks on my DH bikes...so 150-160 is dandy with a motor, and more clearance for obstacles.
KneeOverPedalSpindle..is the general rule for fitting bikes...but when you don't have to pedal with force, you can make some exceptions.

Lower seat equals lower center of gravity.
Lower center of gravity equals better handling.
Seat only needs to be high for leg extension while heavily pedaling.
With a motor...saddle as low as comfortable...it's a couch with a destination...whatever feels comfy.

 

[WoodlandHills]

How about the lowered seat as far as handling when trail riding? Lots of ICE dirt bikes have a very close seat to footpeg distance compared to a bicycle and I am thinking an ebike ought to be closer to a powered bike than a non-power one.

I find I have to keep sliding back on the seat all the time despite it being as far forwards as it gets. I should say now that I have an NCX suspension seatpost and a Selle Lookn Moderate seat. I chucked the low rise 60mm stem for one with an adjustable rise that is rotated to the 90degree position with stock flat bars. I am changing to Answer 720 am bars to get more width and a better angle for my wrists and forearms.

 

[Drunkskunk]

How about the lowered seat as far as handling when trail riding? Lots of ICE dirt bikes have a very close seat to footpeg distance compared to a bicycle and I am thinking an ebike ought to be closer to a powered bike than a non-power one.

That depends. A dirt bike has a very high seat compared to other motorbikes, it also has very high pegs. The butt-to-boot distance might be low, but the butt-to-rut distance is very high.

A high center of gravity is more stable and easier to balance. a low center of gravity is more nimble and precise. At pedal bike speeds, it really comes down to personal taste. What makes your wife happy?

 

[WoodlandHills]

She would like to be able to touch the ground when seated which argues for a relatively low seat and she wants stability and security when riding. Really, I ought to sell the fat ebike and put the motor on to a fat tire cruiser for her.

 

[Noamsal]

How about the lowered seat as far as handling when trail riding? Lots of ICE dirt bikes have a very close seat to footpeg distance compared to a bicycle and I am thinking an ebike ought to be closer to a powered bike than a non-power one.

I find I have to keep sliding back on the seat all the time despite it being as far forwards as it gets. I should say now that I have an NCX suspension seatpost and a Selle Lookn Moderate seat. I chucked the low rise 60mm stem for one with an adjustable rise that is rotated to the 90degree position with stock flat bars. I am changing to Answer 720 am bars to get more width and a better angle for my wrists and forearms.

my DH e-bike with 6kw (almost like a motocross bike) is also verry high, the big loss of this is the bad aerodynamic, i can feel strong winds hitting me from the sides when im going at 90kmh on the road, but for offroading its perfect
im building my commuter right now and its alot lower, 20" wheels, lots of torque so the rear wheel goes way back and the seating position (and all the battery weight) is at the front
when setting an e-bike you need to consider mostly comfort, but if this bike needs to do more then take you from A to B like off road\high speeds and stuff you do need to make it suitable for those tasks...

 

[dogman dan]

Set your e bike for comfort first. In a way, same for pedal. If you aren't comfy there as well, you'd simply ride less, tapering to none if it really sucks.

But for sure with the e bike, you don't need to set the leg so straight, unless that is how you are comfy. But yes, if you really plan to pedal hard, then you need a frame where she gets the leg extension, and have the other things like a toe on the ground when stopped and in the saddle. Most are happy to pedal moderately hard, and can do that with a more bent leg. You can do 50-75w with a bent leg ok. For actual faux pedaling, just spinning, any seat position you like is fine.

This is what makes the townie so popular, a lower seat with the pedal forward bikes. For now lower the seat, but if you see a nice pedal forward bike for a good price used, jump on it. My wife loves her electra townie, ladies model step through. She just pedals, but I agree, it's a damn comfy bike!

 

[WoodlandHills]

She would like to be be able to go on the fire roads nearby, so perhaps I could put more aggressive tires onto a cruiser? Does a BBSHD work with a coaster brake? Actually, given the speed she is comfortable with, a BBS02 would probably be sufficient and save some pounds and £s.....!

I am going to have a re-think of SWMBOs bike and concentrate on fitting mine first over the wet winter putting hers off until Spring. I have been getting some arm pump/elbow pain after an hour or so and I want to see if some alt bars make a difference. I think that I need more sweepback to rotate my wrists back and elbows in towards my body, if the Answer 720 does not work I'll try some Jones or Salsa Bend 2s.

 

[motomech]

Since Ebikes are faster, maybe she is afraid of going over the bars, but doesn't realize, or won't admit it.
Work on biking skills, especially braking(frt. modulation).
As her skills get better, she will relax and be more comfortable overall.

 

[Jonathan in Hiram]

There's really two main problems with pedaling with the knees significantly bent, most of can't put out near the power versus a straighter leg pedaling and pedaling hard with knees bent can cause knee damage or exacerbate existing damage.

If someone isn't going to pedal much then there's no real point in being up high enough to do it powerfully and efficiently.

 

[Deafcat]

I've been studying a lot of bike geometry and ergonomics lately as they apply to both conventional and electric bikes, here are a few things to take note of:

1- Shorter cranks are often more efficient, and especially make immediate sense on an ebike, where your pedals don't need to deliver all the power. further reading:
http://www.cobbcycling.com/crank-length-coming-full-circle/

2- wider tires and lower pressures, and the resulting increase in rolling resistance, is much less a concern thanks to the extra power... allowing one to take greater advantage of the traction and soft ride provided.

3- cockpit position and saddle height can be relaxed, this change in ergonomics is due to the fact that less of your weight is focused on the pedals, instead moving to the saddle (becoming a seat)

4- these effects are different between various styles of ebikes, depending on their application... some riders will be wanting a more conventional, pedal-assist road bike setup, others are riding heavy weight trail and downhill electrics, etc.


edit: speaking of which, the build I'm doing right now has 140mm cranks.

 

[WoodlandHills]

I did about 30 miles with the 150mm crank arms and so far I have about 10 or 12 miles on the 127s. I actually like the shortys once I got used to the smaller circle of rotation. It feels easier on my legs and knees standing on long descents to not have one foot so far in front of the other and, as I said before, I am just along for the ride on the hills.

 

[Chalo]

I deal with customers all the time who want to set their seat height so they can get their feet on the ground comfortably without stepping off the saddle.

I tell them, "if your bike is for standing around, set the seat low enough that it works well for that. If it's for pedaling around, set the seat high enough that it works well for that."

If the wife doesn't pedal, then it doesn't matter what her seat height is, does it? But if she does pedal, put it at the right height for pedaling and tell her to deal.

 

[Drunkskunk]

I've been studying a lot of bike geometry and ergonomics lately as they apply to both conventional and electric bikes, here are a few things to take note of:

1- Shorter cranks are often more efficient, and especially make immediate sense on an ebike, where your pedals don't need to deliver all the power. further reading:
http://www.cobbcycling.com/crank-length-coming-full-circle/

Good read, thanks for the link.

 

[WoodlandHills]

I deal with customers all the time who want to set their seat height so they can get their feet on the ground comfortably without stepping off the saddle.

I tell them, "if your bike is for standing around, set the seat low enough that it works well for that. If it's for pedaling around, set the seat high enough that it works well for that."

If the wife doesn't pedal, then it doesn't matter what her seat height is, does it? But if she does pedal, put it at the right height for pedaling and tell her to deal.

I didn't just celebrate my 30th wedding anniversary by telling my wife to "deal"..... ........ But, point taken: I cut a couple of inches off her seatpost (it was bottomed out) today.

 

[dogman dan]

Yeah, let Chalo tell your wife to deal, I wouldn't do it. 35 years for me.

But he is correct, if the goal is to maximize the riders input on the ride, she needs to set that seat to the correct, straighter leg height. You'll need to do that, if the rides need maximum range. But for casual riding, lowering the seat does no harm. You can still pedal, even if less efficiently. Eventually, hunt down that pedal forward bike that makes both possible, if the roads are not so rough she needs an mtb frame.

Since you just cut down her seat post, it's possible the seat was too high for her leg before. Too high is not the goal, get her seat just right for her leg.

Re the bars, straight bars will cramp my wrists bad, unless I ride 100% of the time in the trail riding, gorilla posture. Lots of elbow bend. For street riding, or dirt at the non competitive level I ride, I much prefer a bar with some rise, and some sweep back. For street, even more rise and sweep, with cruiser or bmx bars. I'm a tall guy, so most bikes don't really fit me so great. I get that long seat post, and then a flat bar will kill me. I need some rise too.

 

[spinningmagnets]

I am a fan of the "crank forward" / "feet forward" style of frame for a street commuter. I would say that the KHS Manhattan Smoothie has the lowest seat position.

 

[USAEBIKECO]

Always make sure your feet are able to touch the ground quickly in case of an emergency where you need to stop fast.

 

[Chalo]

What is the problem with just stepping off the seat, like cyclists have been doing since ever? Are y'all nailed down or something?

 

[WoodlandHills]

What is the problem with just stepping off the seat, like cyclists have been doing since ever? Are y'all nailed down or something?

The problem is low skills which make her feel insecure riding which make her reluctant to ride much which causes her to continue to have low skills. I wonder if she was made to feel more comfortable in a security sense by being able to put her foot down while seated, she might be more likely to ride more often thus breaking the cycle.

 

[Leebolectric]

Dropper post...she can be wherever she wants :wink:

http://www.jensonusa.com/Dropper-Posts?s=l

 

[Chalo]

The problem is low skills which make her feel insecure riding which make her reluctant to ride much which causes her to continue to have low skills. I wonder if she was made to feel more comfortable in a security sense by being able to put her foot down while seated, she might be more likely to ride more often thus breaking the cycle.

.

That's the rationale behind the Electra Townie and its spiritual descendants, and such bikes are almost universally beloved by those who've owned them. If they came in more sizes, I might have owned one myself by now.

I think that given electric propulsion, the choice of seat height is almost arbitrary-- with the understanding that nearly full leg extension makes pedaling more comfortable and efficient. If your wife can get around as effectively as she likes with the seat "too low", then it's not really a problem.

 

[Chalo]

Dropper post...she can be wherever she wants :wink:

http://www.jensonusa.com/Dropper-Posts?s=l

The Hite Rite was a thing in the 1980s. I guess there's no such thing as a bike gimmick that never returns.

 

[Leebolectric]

ya, they existed....but i could do the adjustment with a QR and a leg pinch as easily...
...the remote lever is MUCH easier, without the contortionist positions on a moving bike....
...much better for the described newb. :wink:
The future is awesome.