Newbie PAS questions

[Limeybastard]

Whats the terminology used to know if the PAS can be set to a speed limit on a particular brand or model for example? Also, what terminology name is used to know if an e-bike can just work in electric mode only without the need to pedal at all, similar to free coasting - if this option exists or not I dont know. Many thanks.

 

[Dave Rocks]

PAS Speed Settings.
Throttle Push-assistance.

This is what my eBike Display USER MANUAL calls it.

 

[Limeybastard]

PAS Speed Settings.
Throttle Push-assistance.

This is what my eBike Display USER MANUAL calls it.

Thanks. But I was asking in relation to researching on purchasing an e-bike, under specs what verbiage should I be looking for?

 

[Dave Rocks]

Speed​

Class 3 electric bike, with 28mph pedal assist and 20mph throttle

 

[m@Robertson]

"Riding without the need to pedal at all" means you need a throttle. Class 2 ebikes, strictly speaking, are the ones with throttles. You want to either look for a bike that says it has "a throttle" or designates itself as a "class 2 ebike" What @Dave Rocks is saying can also come into play: That is, a manufacturer will include a throttle on a Class 3 bike and that throttle is only functional up to the Class 2 limit. I won't get into the whys and wherefores of this as that is not what you asked for.

Setting PAS to a particular speed limit - and in fact your entire question - is a bit of a misnomer. NO ebikes do (or should) have a speed limit. What they have is an 'assist limit'. That means they assist up to a certain speed and then they do not assist any more, leaving further speed increase up to you and your legs/muscles/lungs. Thats particularly meaningful for PAS as when you are pedaling you are working the bike with your muscles to at least some degree. Most simply, you can use the Class 1, 2 and 3 ebike speeds to figure out what the assist limits for your chosen bike are.

But the top speed is up to you. This makes a little more sense if you consider my own example: I build my own bikes. As a part of that, while I may have a motor that peaks at about 28 mph, I geared my bike in such a way that if I can maintain 70-75 rpm cadence, I am traveling at up to 34 mph. Most factory bikes aren't geared like this, but its not uncommon for stronger riders to change out the chainrings or rear cluster so they can pedal hard at higher speeds than the manufacturer intended. It lets them/me ride fast but also get a strong workout.

 

[Limeybastard]

"Riding without the need to pedal at all" means you need a throttle. Class 2 ebikes, strictly speaking, are the ones with throttles. You want to either look for a bike that says it has "a throttle" or designates itself as a "class 2 ebike" What @Dave Rocks is saying can also come into play: That is, a manufacturer will include a throttle on a Class 3 bike and that throttle is only functional up to the Class 2 limit. I won't get into the whys and wherefores of this as that is not what you asked for.

Setting PAS to a particular speed limit - and in fact your entire question - is a bit of a misnomer. NO ebikes do (or should) have a speed limit. What they have is an 'assist limit'. That means they assist up to a certain speed and then they do not assist any more, leaving further speed increase up to you and your legs/muscles/lungs. Thats particularly meaningful for PAS as when you are pedaling you are working the bike with your muscles to at least some degree. Most simply, you can use the Class 1, 2 and 3 ebike speeds to figure out what the assist limits for your chosen bike are.

But the top speed is up to you. This makes a little more sense if you consider my own example: I build my own bikes. As a part of that, while I may have a motor that peaks at about 28 mph, I geared my bike in such a way that if I can maintain 70-75 rpm cadence, I am traveling at up to 34 mph. Most factory bikes aren't geared like this, but its not uncommon for stronger riders to change out the chainrings or rear cluster so they can pedal hard at higher speeds than the manufacturer intended. It lets them/me ride fast but also get a strong workout.

Yes your second paragraph makes sense to me. thanks.

 

[MrLibraryMan]

"Riding without the need to pedal at all" means you need a throttle. Class 2 ebikes, strictly speaking, are the ones with throttles. You want to either look for a bike that says it has "a throttle" or designates itself as a "class 2 ebike" What @Dave Rocks is saying can also come into play: That is, a manufacturer will include a throttle on a Class 3 bike and that throttle is only functional up to the Class 2 limit. I won't get into the whys and wherefores of this as that is not what you asked for.

Setting PAS to a particular speed limit - and in fact your entire question - is a bit of a misnomer. NO ebikes do (or should) have a speed limit. What they have is an 'assist limit'. That means they assist up to a certain speed and then they do not assist any more, leaving further speed increase up to you and your legs/muscles/lungs. Thats particularly meaningful for PAS as when you are pedaling you are working the bike with your muscles to at least some degree. Most simply, you can use the Class 1, 2 and 3 ebike speeds to figure out what the assist limits for your chosen bike are.

But the top speed is up to you. This makes a little more sense if you consider my own example: I build my own bikes. As a part of that, while I may have a motor that peaks at about 28 mph, I geared my bike in such a way that if I can maintain 70-75 rpm cadence, I am traveling at up to 34 mph. Most factory bikes aren't geared like this, but its not uncommon for stronger riders to change out the chainrings or rear cluster so they can pedal hard at higher speeds than the manufacturer intended. It lets them/me ride fast but also get a strong workout.

I have a question. Is there a governor of some type on a Trek Allant+ 7S (which is a Class 3 bike) that limits (or even prohibits) a rider from easily reaching 28mph?
Thanks!

 

[m@Robertson]

I have a question. Is there a governor of some type on a Trek Allant+ 7S (which is a Class 3 bike) that limits (or even prohibits) a rider from easily reaching 28mph?
Thanks!

Speaking generally as the real people to ask about this would be Trek customer service, with at least anecdotal experience from Trek riders:

That bike advertises "Assist up to 28 mph", which is not at all the same thing as "motor makes the bike easily reach 28 mph". All the advertised claim is saying is that the motor will not shut off until your speed reaches 28 mph. Stated differently, in literal terms its not claiming to be able to get you up to that speed. Its claiming it will not stop assisting you until it reaches that speed.

Now, maybe it physically can "easily reach 28 mph" but, the bike is a throttle-less pedelec with a relatively low-powered motor that uses a torque sensor, so what you get out of the motor is dependent on the muscle you put into your pedaling. You will need actual riding experience to know if Trek set up that motor to go fast without a lot of effort on your part to engage that torque sensor. The advertising overall on the web page certainly implies that its easy to hit 28 mph.

 

[PedalUma]

Speaking generally as the real people to ask about this would be Trek customer service, with at least anecdotal experience from Trek riders:

That bike advertises "Assist up to 28 mph", which is not at all the same thing as "motor makes the bike easily reach 28 mph". All the advertised claim is saying is that the motor will not shut off until your speed reaches 28 mph. Stated differently, in literal terms its not claiming to be able to get you up to that speed. Its claiming it will not stop assisting you until it reaches that speed.

Now, maybe it physically can "easily reach 28 mph" but, the bike is a throttle-less pedelec with a relatively low-powered motor that uses a torque sensor, so what you get out of the motor is dependent on the muscle you put into your pedaling. You will need actual riding experience to know if Trek set up that motor to go fast without a lot of effort on your part to engage that torque sensor. The advertising overall on the web page certainly implies that its easy to hit 28 mph.

Along with physical gearing changes there are programing changes that can be done on many bikes. One easy one is resetting wheel diameter. If I tell my bike that it has ten-inch wheels then they would need to spin a lot faster to hit the 28Mph limit then if I told it that it has 32" wheels.
The metric conversion trick is cool. Switch from Imperial to Metric on the display. Then tell it that its wheels are 40% smaller than actual. When you see your speed as 25 Kph on the display it will then actually be exactly 25 Mph. The physical limit in programing will then be 39 Mph, 40% faster. Not that your bike can do that.
One foolish person a zip tie on his throttle so it was always on full power. He called it cruise control. Do not do that.

 

[m@Robertson]

Along with physical gearing changes there are programing changes that can be done on many bikes. One easy one is resetting wheel diameter. If I tell my bike that it has ten-inch wheels then they would need to spin a lot faster to hit the 28Mph limit then if I told it that it has 32" wheels.
The metric conversion trick is cool. Switch from Imperial to Metric on the display. Then tell it that its wheels are 40% smaller than actual. When you see your speed as 25 Kph on the display it will then actually be exactly 25 Mph. The physical limit in programing will then be 39 Mph, 40% faster. Not that your bike can do that.
One foolish person a zip tie on his throttle so it was always on full power. He called it cruise control. Do not do that.

Huh I had never heard of that very clever metric trick but it makes perfect sense. When doing this myself back in the day before I started building my own, the easiest I had found was to halve wheel size, so whatever speed you saw on the display was reasonably easy to convert in your head.

 

[PedalUma]

This bike has a nominal power depletion rate of only 350W. It is a three-speed with a coaster brake and a handmade European lugged frame. I tossed the wheel magnet, speed pick up, throttle and brake levers and then told it that it has miniature 100cm circumference wheels because less is more. The battery weighs only three pounds. When a $7,000 Turbo Levo passed me yesterday on a gravel trail I raced it using this bike and won. I wish it was for pinks.