Pedal assist sensor or alternatives?

[bikerough]

So, I got the 48/1000 yescomusa kit, a monster 20 ah battery (lol, at least I hope I have it and it can make it safely here from China), and a crappy full suspension frame to build it on (still looking for a better frame though), and trying to figure out which technology would be the best in ensuring proper pedal assist. Sure, I will have enough power to take my roundtrip commute just on battery power - but that's not fun. I want to pedal when I want, as much as I want, and be able to shave the hills off with the motor.
I saw pedal sensors being sold that would keep the speed under 20 mph, and ensure some kind of pedal assist. What would be the best technology (sensor, electric) to get in addition to the kit to have that option? Is it worth getting it? In other words, I want to use pedal assist to have controlled workouts, and have an option to turn it off and go solely on the motor/human power.
Thank you for all your tremendous help so far.

 

[winkinatcha]

The only pedal assist I have used and abused is based on a hall sensor and plastic ring with magnets that fits on the bottom bracket and crank axle respectively... the sensor feeds into the same connections as my throttle on my controllers.

In my personal opinion, this system takes a bit of getting used to and the main thing I have learnt from it is how to "ghost pedal" to keep the motor powered without using a throttle.

I reckon, unless you have to have it, this kinda system doesnt really encourage pedalling for workout, just encourages one to move ones legs but not necessarily apply force.

if you are looking to have the option of a good workout, get yourself a big chain ring, say 53 tooth so that you can keep a reasonable pedal speed with the motor (assuming about 30 mph) and then you'll find you can pedal to assist the motor a lot easier at its higher end and will probably pedal more on hills etcetera to try to maintain the motors top speed.

hope that makes sense

joe

 

[Animalector]

If you get yourself a CycleAnalyst (CA), you can configure either a speed limit or a current limit. so.. basically forget the PAS / pedelec

Example 1
in my setup I have just the throttle which is connected to the CA, and then to the controller. I can configure the top speed for say 20km/h. Now, if I don't pedal at all, the CA will deliver full current and accelerate quickly to get me up to 20km/h but then reduce the current to keep me at 20k/h constant. If I want to ride faster, it will be 'ALL' pedal effort only (with no assistance from the motor at all)

Example 2
Same setup as above, but configure the CA to Current Limit of 12 Amps (@48V = 576W) . If I don't pedal at all, the CA will limit the current and I will accelerate slowly up to whatever speed 576W will accomplish (perhaps 30km/h). Any additional pedal effort will result in greater speed. However now, the motor will potentially be assisting the same 576W at whatever speed you want to pedal.

THe benefits of a Cycle Analyst are well worth the $150 or whatever it costs. On a side note... just pedal always. it is a bike after all and if you do get pulled over by police, even if you're doing 45km/h and just spinning the pedals with no actual assistance, at least you can 'claim' you were doing all the work

Enjoy
Andy