Why don't you pedal your ebike?

[hillslayer@]

I don’t pedal because chainring is too small and programming wrong on the current Bbs02 I’m using. The programming is too aggressive to keep up with pedalling and also the natural spin speed of the motor isn’t so conducive to actually pedalling. I absolutely prefer to pedal (a lot) but torque sensing makes it much more enjoyable and having the right gear reduction ratio is very important imo

Program cable is 10 bucks

 

[ebike4healthandfitness]

I find that going from 175mm cranks to 165mm made pedaling goes from painless to painful. I had to raise my seat by 10mm to counter that. The seat height gain is proportional to the crank length drop.

This would work much better on a bike designed for it.

Looking back I found a post where you did better with 145mm compared to 175mm:

Crank length?

Our LBS in Daphne, AL has the ability to order various crank lengths in a few days. One guy who works there has has experience with short cranks and reduced knee problems. They can be educated and some actually know stuff. Not all though. These guys build bikes for some of the older Senior Class...

endless-sphere.com

I am a 30 year old and i have always had one problematic knee. But i also have rather long legs. I thought a 175mm crank was appropriate for my height, but it just lead to discomfort and more pain. The 145mm sinz cranks i had on another bike made it very easy to pedal. I feel like i lost some of my ability to really crank on the pedals, however when i do really push on the 145mm cranks, i never get knee pain as a result.

( 20" wheel with a rather tall tire out back, 26" up front )

Here is my pike's peak race bike with the sinz 145mm cranks installed. The 165mm cranks previously on it would drag on the ground if i took a turn too sharp.. lol..

 

[neptronix]

Oh yeah. That bike barely got pedaled because it was a torque monster designed only for scaling mountains. Leg power output wasn't good, but didn't need to be good at ~4kW. I immediately went back to 175mm cranks for all future bikes, only using shorter ones when some kit required it ( example: lightest bike kit ). I threw those cranks away because they only served a function on that bike ( make the cranks not hit the ground ).

 

[ebike4healthandfitness]

Oh yeah. That bike barely got pedaled because it was a torque monster designed only for scaling mountains. Leg power output wasn't good, but didn't need to be good at ~4kW. I immediately went back to 175mm cranks for all future bikes, only using shorter ones when some kit required it ( example: lightest bike kit ). I threw those cranks away because they only served a function on that bike ( make the cranks not hit the ground ).

But back then you said 175mm led to more discomfort and pain. And when you really push on the 145mm you never get knee pain as a result.

 

[neptronix]

I've also had a tibia bone cut and realigned since then, and i was 100lbs heavier. This was ~13 years ago.
I might have been using 170mm cranks back then. My legs like 175mm these days. My right leg is no longer freakishly duckfooted.

 

[hillslayer@]

I will say if you're trying to pedal a bafang mid-drive at full power and want to keep up , short cranks help those motors like to spin.

 

[fill]

Ha ridding a UK/EU regs compliant conversion I have no option but to pedal unless rolling downhill. Though the motors speed capacity and any legal limits set on it probably has more to do with pedal input than anything, since if pedal input has little or no impact why bother with it unless the law requires a ghost pedalling situation..

Not every cyclist is a fitness freak, and while i do appreciate i am in a small subset, to me exercise is something incidental to life a side effect of daily business, and at age 16 when i could legally let an engine do the work of transport i was happy to retire the cycle to summer treks down the towpath to remote pubs and similar jaunts.

 

[wturber]

Take notice also on the costs of a 40 mile bike ride at medium human speed ( ~13mph )
- For most people this will expend 2000 calories, which almost doubles food intake for the day.. will cost something like $4-$15 worth of food.. more expensive than gasoline for a car.. and we traveled at a fraction of the speed!
- Running an electric bike at human bike speed won't even use a kilowatt hour of electricity, but a kilowatt hour costs $0.10-$0.3 depending on where you live.

Many good points, but I get my extra calories on regular bike rides mostly from relatively inexpensive carbohydrate foods. I don't spend anywhere near $4 for my extra 1000-2000 calories - mostly generic fig bars and sugar added to tea.

I also consider that a certain degree of physical exercise is required for good normal health. So comparing bike riding to other modes of transportation that don't provide that benefit is not really a like-for-like comparison. That said, you are 100% correct that electricity is way cheaper even than low cost carbs. This is one reason why my car replacement, in-town cargo bike is an ebike. It is more efficient and more effective. It is a very practical mode of transportation for trip of less than 10 miles. Since our cars are very impractical 2006 350zs, the ebike with trailer is sometimes even better at hauling stuff around. But I still pedal and put in real effort. My typical human watt output while ebiking is 125-150 watts if my torque sensing BB and Cycle Analyst are to be believed.

 

[ebike4healthandfitness]

Take notice also on the costs of a 40 mile bike ride at medium human speed ( ~13mph )
- For most people this will expend 2000 calories, which almost doubles food intake for the day.. will cost something like $4-$15 worth of food.. more expensive than gasoline for a car.. and we traveled at a fraction of the speed!

Either that or the person lost up to .571 lbs of fat. (Reason: one pound of body fat contains 3500 calories and 2000/3500 = .571 lbs)

Actually it is even possible for the person to lose even more than .571 lbs of fat if the cycling trip actually caused the person to reduce their caloric intake.

 

[wturber]

Either that or the person lost up to .571 lbs of fat. (Reason: one pound of body fat contains 3500 calories and 2000/3500 = .571 lbs)

Actually it is even possible for the person to lose even more than .571 lbs of fat if the cycling trip actually caused the person to reduce their caloric intake.

True. But that means the person had to previously consume the food and calories in order to have the fat on hand (or belly) to burn. So the points @neptronix made about calorie consumption, energy efficiency and cost of calories remain.

 

[ebike4healthandfitness]

True. But that means the person had to previously consume the food and calories in order to have the fat on hand (or belly) to burn. So the points @neptronix made about calorie consumption, energy efficiency and cost of calories remain.

People who are overweight or obese don't plan it that way though. In fact, most gain weight and never ever lose it. So for these people their body fat calories are a free opportunity.

 

[wturber]

People who are overweight or obese don't plan it that way though. In fact, most gain weight and never ever lose it. So their body fat calories are essentially "free".

Not free. Just previously paid for. Also, that person doesn't have to be overweight. Even people with "normal" BMIs can have a lot of fat on board ready to be burned. For instance one calculator give a person at my height of 5'10" a range of 130-170 lbs as being normal. And as it is, I personally have put on 5-8 lbs in the past 3-4 weeks. So I've "banked" some fat. And it wasn't free. I really did enjoy that ice cream and those thin mint cookies. And that brings up another side benefit of burning calories while cycling. You get to eat more enjoyable food. The cost, calorie and efficiency issues still remain. But it is worth mentioning not only health benefits, but subjective quality of life benefits as well. Yummm.

 

[ebike4healthandfitness]

Not free. Just previously paid for.

Previously paid for sure but certainly not for the purposes of adding 50lbs or more of body fat so they could do a lot of exercise.

Even 15 lbs....what used to be called "the freshman 15" in college doesn't happen because these kids are planning on doing a whole lot of cycling (or exercise) on their summer break.

 

[Hummina Shadeeba]

How does the position of mass effect handling?

Motorcycle Center of Gravity Motorhead Myths

Does a low center of gravity improve handling? Kevin Cameron says it depends on what kind of handling you are after and it isn’t the answer to quick-handling sportbikes.

www.cycleworld.com

What is a bike pivoting around when turning if not it’s center of mass?

 

[bengxe]

How does the position of mass effect handling?

Motorcycle Center of Gravity Motorhead Myths

Does a low center of gravity improve handling? Kevin Cameron says it depends on what kind of handling you are after and it isn’t the answer to quick-handling sportbikes.

www.cycleworld.com

What is a bike pivoting around when turning if not it’s center of mass?

Bikes pivot around the rear contact patch in normal turning. If you mean leaning, it would have to pivot around the center of mass of the rider/ bike combined. For most people on e-bikes, that point is significantly higher than the bike frame. So to maximize ease of leaning into a turn I'd say you want the bike's COM as high as possible, but for overall ease of handling I think you want it centered between the control surfaces (grips, pedals, seat).

 

[ebike4healthandfitness]

Bikes pivot around the rear contact patch in normal turning. If you mean leaning, it would have to pivot around the center of mass of the rider/ bike combined.

Normal turning? All bikes have to lean when turning.

 

[bengxe]

Normal turning? All bikes have to lean when turning.

Thanks for that stunning observation, but lean angle is a function of speed so I think it is worth differentiating from the yaw motion of the bike frame.

 

[ebike4healthandfitness]

Thanks for that stunning observation, but lean angle is a function of speed so I think it is worth differentiating from the yaw motion of the bike frame.

In post #65 (quoted below) you differentiate normal turning from leaning.

Bikes pivot around the rear contact patch in normal turning. If you mean leaning, it would have to pivot around the center of mass of the rider/ bike combined.

All normal turning involves leaning no matter how slow the person is going. They are not separate from each with separate pivot points. A bike does not pivot around the rear contact patch.

 

[Hummina Shadeeba]

I’ve got a couple theories of my own or I picked up somewhere:

Am I wrong in believing a bike would be quickest to do a serpentine course if its mass were condensed to the smallest point and that this point would also be the turning pivot point?


If this were true a bike could turn equally as quickly if the mass were high or low and what determines its quickness is if that mass is more densely centered as it has less distance to move. I’m assuming the moving of the mass to initiate and make the turn is the obstacle and the further that mass is from the pivot point the further it has to move and more force required and the longer it will take

 

[bengxe]

In post #65 (quoted below) you differentiate normal turning from leaning.



All normal turning involves leaning no matter how slow the person is going. They are not separate from each with separate pivot points. A bike does not pivot around the rear contact patch.

Yaw and lean are quite literally different things with different pivot points.

 

[bengxe]

I’ve got a couple theories of my own or I picked up somewhere:

Am I wrong in believing a bike would be quickest to do a serpentine course if its mass were condensed to the smallest point and that this point would also be the turning pivot point?


If this were true a bike could turn equally as quickly if the mass were high or low and what determines its quickness is if that mass is more densely centered as it has less distance to move. I’m assuming the moving of the mass to initiate and make the turn is the obstacle and the further that mass is from the pivot point the further it has to move and more force required and the longer it will take

More centralized mass is better, but you need to look at the mass of the rider and bike together. That's why the bike's ideal COM will be higher than you can use a kickstand with.

 

[Hummina Shadeeba]

More centralized mass is better, but you need to look at the mass of the rider and bike together. That's why the bike's ideal COM will be higher than you can use a kickstand with.

I’m assuming rider and bike mass together.

when you say centralized mass is quicker turning.. centralized in what regard? wouldn’t the pivot point be wherever the center of mass was? If that’s the case I don’t see how it’s location matters and more important would be how much of the mass is compacted as close to the pivot point

 

[bengxe]

Most riders are significantly heavier than their e-bike, making the COM of the combined unit well above the bike frame. So centralizing the bikes mass usually means raising it as high as possible. For most of us, the height of the COM will make a much larger difference than how longitudinally centralized the mass is.

 

[hillslayer@]

I built a dual motor mid-drive with 20 lbs of battery mounted low as possible on the downtube and a 16 lb DD hub. On a 29er mountain bike frame my total weight is probably something over 85 lbs and it handles almost as good as before adding an extra 30 lbs . I think keeping added weight low as possible really makes for a super stable ride

 

[ebike4healthandfitness]

Yaw and lean are quite literally different things with different pivot points.

The center of mass will be the pivot point for the yaw. The bicycle is not going to pivot on the rear contact patch as you wrote.