Pedal assist info. ?

[Lbrava]

New to ebikes & just have a general question on pedal assist. Are all pedal assists the same ? In other words does the amount of power you generate from pedaling transfer to the amount of power the motor puts out ? Hope the question makes sense. I guess what I'm trying to figure out is let's say you have a 2000 feet climb & if the e motor assist is matching your pedal power than climbing the 2000 feet would only take as much pedaling power to reach 1000 feet ? I heard some one say there bikes motor is a 2:1, so would that mean to top the 2000 foot climb it would be like pedaling 500 feet ?
I tried google search didn't see anything also bike web sites have a lot of power claims but don't explain how that power gets to the ground or at least I missing it somewhere.
Thanks

 

[fauconnier]

Pedal Assist Systems - Learn

Grin Technologies

ebikes.ca

 

[Djangodog]

There are different classes of pedal assist only bikes. Class 1 is assist up to 20 mph and Class 3 is assist up to 28 mph. Class 2 adds a throttle up to 20 mph.

Manufacturers have assorted drives with an assortment of power outputs. Hub drives directly drive the wheel where mid drives apply power to the cranks and make use of the bikes drivetrain. Even if the assist is rated to provide up to 3x your input in a high assist mode, (they typically have 3-5 assist modes), It will still only provide it’s maximum wattage. An example would be that my Yamaha Cross Core has a 250 watt, 500 watt peak motor that provides up to 70 Nm of torque, so if I am riding in the highest assist level and I am putting in 300 watts, the assist cannot provide 3x my input, so it is not really as simple it would initially appear.

Because I still enjoy riding non-electric bikes as well as my ebike and because I like to ride with my wife, I prefer the Class 1 and often ride at near or above the maximum assist speed on the flats. My wife can choose the assist level that allows us to stay together. She doesn’t really enjoy higher speeds, so a class 3 would be a waste for us and I like to earn anything above 20 mph. The assist is nice when accelerating because it gets you up to speed easily. It is really nice on the hills and rather than dropping down to 8-12 mph, I am riding up the steep sections at 12-18 mph. I generally ride in eco + or eco mode, (there is also a standard and high).

Your choice depend on your desires and needs. A Class 3 is certainly a lot of fun provided that you can handle the higher speed and want it. A throttle has benefits as well, but that is a whole other topic.

 

[rich c]

There are 2 distinctly different PAS systems, torque sensor and cadence sensor. Torque sensor is a system that measures the effort you put on the pedal and that tells the controller how much current to send to the motor. This variable system works in every level of assist. The cadence system is like an on/off system. It senses magnets moving past a sensor and that tells the controller that you are moving the pedals and it sends current to the motor based solely on what level of assist you have chosen. I don't know how to address your thought process on taking that to a length of pedaling factor. I think you are confusing effort and distance.

 

[JES2020]

New to ebikes & just have a general question on pedal assist. Are all pedal assists the same ? In other words does the amount of power you generate from pedaling transfer to the amount of power the motor puts out ? Hope the question makes sense. I guess what I'm trying to figure out is let's say you have a 2000 feet climb & if the e motor assist is matching your pedal power than climbing the 2000 feet would only take as much pedaling power to reach 1000 feet ? I heard some one say there bikes motor is a 2:1, so would that mean to top the 2000 foot climb it would be like pedaling 500 feet ?
I tried google search didn't see anything also bike web sites have a lot of power claims but don't explain how that power gets to the ground or at least I missing it somewhere.
Thanks

There are two types of pedal assist, cadence and torque.

Torque is the one you describe, converting the pressure you put into the pedal into motor assist.

Cadence, is dependent on turning of the pedal. The faster you pedal the more motor assist, limited by the PAS level set on the display.

 

[6zfshdb]

If you haven't already done so, I would try before you buy. There is no set standard for PAS systems and performance varies greatly from make to make.

 

[Lbrava]

Thanks for all info, & with a little more digging (that reading thing always gets me !) I think I now basically understand what these bikes do. For example the Trek Levo comp vs the Trek Levo SL is explained on there site. The SL is a 1:1 ratio assist with a smaller motor & battery which makes a lighter bike but will take more human power to get you where your going. VS, the Levo comp which is a 2:1 motor where you can choose your power levels to as much as a 410% increase in you pedal input. Getting that kind of energy out of a motor requires bigger motor & battery hence heavier bike but less human power to get you where your going.
It seems most emtb bikes fall under the Trek Levo comp. style where you can choose your power level way beyond your pedal input regardless of type of sensor.
I got to test ride a 2022 Giant Stance & a 2019 Trek Powerfly today & both were very smooth in all power levels, both seemed very similar on full power. The Giant seemed to accelarate faster than the Trek I'm guessing that's due to a larger motor. The Trek has 500W motor & Giant I think was 620W. But I liked the Trek better for some reason.
Anyway I'm going to buy a bike with a 600W motor or bigger.

 

[retiredNH]

Motor wattage is NOT what you should focus on, for a variety of reasons. First, you're confusing battery wattage (technically watt-hours, an energy storage measure) with motor power, measured in watts. For instance, IIRC, the Trek powerfly has a 250 watt motor and a 500 watt hour battery.
Second, the motor power interacts with other drive train components to give the overall feel when you ride. Things like chainring size, and rear gearing make a huge difference.
Third, and most important, there's no standards for stating motor wattage. Between brands, comparing is very difficult.

 

[Lbrava]

I'm not clear on what your saying. Are you saying the Giant motor I rode put out the same power as the Trek I rode ? Obviously gearing makes difference. In your opinion when shopping for emtb & comparing there motor advertised power claim what should you look for ?
Also interesting in the Trek & Giant I rode both have advertised 250w motors but the Giant seemed noticeably quicker off the line than the Trek regardless of gearing. I tried both bikes in several gears from a dead start. So defiantly a difference of power delivery from 2 different 250w motors.
It seems most of 2022 bikes have larger batterys & claim more torque than there 2020 or earlier models. I guess I'll do some more homework & see if I can find comparisons between motors/batteries from the 500W to 2022 625w advertised upgrades
For example I can get a 2021 Trek used (almost new less than 200miles on it) Rail 5 for 4K with 500w battery or a new 2022 rail 7 for 6.4K same motor but a 625w battery.

 

[retiredNH]

Lbrava, let's parse through the issues you raise.
- Giant vs Trek motor power? Hard to say. Bosch is well known for under-rating power output in order to meet European restrictions. Giant doesn't state the power output of its SyncDrive Sport. However, both Giant and Trek (for current Bosch powered bikes) mention torque, which is a big factor in climbing. Giant is 70NM. Trek is 85NM. Not a huge difference, but it could matter?
- "quicker off the line"? What assist levels were each set at? If the same, then this is no doubt due to the power delivery curves as set by the manufacturers (unless you had a Bafang drive where you could probably tune it...). If the controller is set to ramp up power more quickly, it will feel quicker off the line. I do know that Bosch's CX drives (the ones used in most of their MTBs) allow some level of tuning of power curves if you have certain displays. Most riders, unless they're commuting in a built up area don't spend much time starting and stopping, though, so I would not put much weight in this metric.
- 500W vs 625W (technically not W, but Wh!) is just the difference between battery capacity, which is just a measure of how far you can go on a battery charge (at a given motor assist level)
- final words: Of the major US brands I'm familiar with, Giant, Specialized and Trek (and probably major European brands like Gazelle, R&M etc.), they all play in a pretty competitive market, and all their offerings at a particular price point should perform similarly. I'd focus less on features like power or battery, and more on things like dealer, personal fit, features that matter to you like racks (or not?) etc.

 

[TrevorB]

Torque is how big engine is. Battery wh (WattHours) is fuel tank size.
Buy the one you like feel of the most.

 

[Lbrava]

Thanks for info. guys, for sure Giant, Specialized, Trek seem very similar & I am now focused on personal fit, also long term reliability since I'm looking at used market for low mile 2021 bikes. From what I've read I'm leaning towards a bike with a Bosch motor and from my test ride on the Giant & Trek I'm going to go with a Trek Powerfly or Rail . The Trek just seemed like a better fit/feel too me. And so many variables in "feel" the frame set up, suspension set up, tire pressure, road your on ect. a can of worms for sure but as stated "buy the one you like" is good advice. I know both are good bikes I just like the Trek a bit more. Still a bit hung up on battery size though as I know I'll be using full power mode a lot & l think a larger battery will give me more range.
Hopefully the right deal will come up soon, I was hoping to spend around 4K but now the budget is up to 5.5K.

 

[fooferdoggie]

Thanks for info. guys, for sure Giant, Specialized, Trek seem very similar & I am now focused on personal fit, also long term reliability since I'm looking at used market for low mile 2021 bikes. From what I've read I'm leaning towards a bike with a Bosch motor and from my test ride on the Giant & Trek I'm going to go with a Trek Powerfly or Rail . The Trek just seemed like a better fit/feel too me. And so many variables in "feel" the frame set up, suspension set up, tire pressure, road your on ect. a can of worms for sure but as stated "buy the one you like" is good advice. I know both are good bikes I just like the Trek a bit more. Still a bit hung up on battery size though as I know I'll be using full power mode a lot & l think a larger battery will give me more range.
Hopefully the right deal will come up soon, I was hoping to spend around 4K but now the budget is up to 5.5K.

feel is extremely important.

 

[Alaskan]

Trek offers a range extender on some of their models. this allows you to mount a second 500 watt hour battery in the down tube that is integrated into the system, such that your remaining battery percentage and estimated range reflect the energy in both batteries. You can leave the second battery behind if you are sure you are not going to use it or bring it along if their is any doubt. A good cure for "range anxiety. I am not sure if the Powerfly or Rail can accommodate the range extender. Here is my Trek Allant with the 625 internal battery and the range extender mount piggy back on the downtube. There is a frame bag hanging off the top tube.

 

[Lbrava]

Nice pic !
Wow, didn't know about the range extender. I've heard of guys carrying an extra battery. Defiantly would add some range. I did see where on the low end powerflys that have the 500w battery will accept a 625w battery. But at the price of those batteries I hope I won't be needing one. I'm pretty sure most of rides will be 15-40 mile range, but ya never know.

 

[JES2020]

Torque is how big engine is. Battery wh (WattHours) is fuel tank size.
Buy the one you like feel of the most.

Horsepower = Torque x RPM / 5,252 (where 5,252 is the conversion between lb-ft and horsepower)
Horsepower is the indication of power available (example piston displacement ), size.

Torque is how much energy is available to turn ( the wheels on a bike for example).
So you can have a very small engine/motor with very high torque, for example, a power hand drill.

 

[Alaskan]

Nice pic !
Wow, didn't know about the range extender. I've heard of guys carrying an extra battery. Defiantly would add some range. I did see where on the low end powerflys that have the 500w battery will accept a 625w battery. But at the price of those batteries I hope I won't be needing one. I'm pretty sure most of rides will be 15-40 mile range, but ya never know.

At 15-25 miles you will be golden with the 625 Bosch battery, heck you could likely do 20 miles all in Turbo, the highest assist level on a Bosch powered ebike. Please note, at the beginning of my ebike journey in 2018, I had a hard time imagining doing much more than 20 miles. Now that is a short ride for me.

The ride in that photo 2 years ago at age 69 was 48 miles with 5,000 feet of climbing to where that shot was taken. On a weekly basis, I am doing at least two rides of 35-50 miles. On my lighter weight (39 lbs.) Bosch speed motor powered carbon frame e-gravel bike, those distances are now doable on one battery with mid to higher assist (not Turbo though).
After a major, "widowmaker" heart attack back in 2017 and now learning to live with cancer, I am fitter and trimmer than I have been in decades (55 lbs. lighter than before the heart attack), riding 400-600 miles per month and hardly ever driving a car. To say ebikes have radically changed my life would be an understatement.

I've never had any regrets when going over budget and springing for a better bike. Every day I ride one of these fun machines, I have a smile on my face, the boy in me reemerges and I know I am doing good things for my health, our financial security and, in a small way, our planet.

 

[Sparky731]

At 15-25 miles you will be golden with the 625 Bosch battery, heck you could likely do 20 miles all in Turbo, the highest assist level on a Bosch powered ebike. Please note, at the beginning of my ebike journey in 2018, I had a hard time imagining doing much more than 20 miles. Now that is a short ride for me.

The ride in that photo 2 years ago at age 69 was 48 miles with 5,000 feet of climbing to where that shot was taken. On a weekly basis, I am doing at least two rides of 35-50 miles. On my lighter weight (39 lbs.) Bosch speed motor powered carbon frame e-gravel bike, those distances are now doable on one battery with mid to higher assist (not Turbo though).
After a major, "widowmaker" heart attack back in 2017 and now learning to live with cancer, I am fitter and trimmer than I have been in decades (55 lbs. lighter than before the heart attack), riding 400-600 miles per month and hardly ever driving a car. To say ebikes have radically changed my life would be an understatement.

I've never had any regrets when going over budget and springing for a better bike. Every day I ride one of these fun machines, I have a smile on my face, the boy in me reemerges and I know I am doing good things for my health, our financial security and, in a small way, our planet.

I echo Alaskan 100% (except for the medical issues - sorry to hear but happy to hear of current rides). I also have an Allant with a 625w + the 500w Range Extender And 4,300 miles on the odo. I also ride every day — in Turbo all the time— why not? On solo rides I can get about 55-60 miles. Hundreds of miles with group rides.

Get the bike you that matches your rides. If primarily off-road, definitely the Rail. If distance trail pleasure riding, get an Allant class 3. You will have the speed when you want it and never regret having it.

 

[Lbrava]

Well I just bought a 2022 Mondraker Crafty R medium with a 750w battery. Has almost identical geometry as the Trek Rail L. I rode a Trek Rail 7 L & it fit me well. Hopefully the Mondraker is as good of bike as the Trek. Unfortunately I won't get for another 2 weeks.
I searched & searched for a used bike but just couldn't find what I wanted for what seemed a reasonable price. So I busted the budget & went new.

 

[Stefan Mikes]

Hopefully the Mondraker is as good of bike as the Trek.

Your Mondraker has the new Bosch Smart System, surpassing most of current Trek e-bikes in this respect. (Only Trek Rail 9.9 and 9.8 get the Smart System, at an exorbitant price).
Congratulations!

May I ask what you paid for the e-bike?