Same motor+battery, small diameter wheel+tire equals more force, not more torque.

[rcgldr]

For example, assuming 16X and 18XL have the same pack, motor, ..., the 16X won't have more torque than 18XL, but it will generate more accelerating and braking force for the same amount of torque due to the smaller radius: force = torque / radius.

I have  V85 = 35 lbs, 16 inch tire, and 18XLV2, 53 lbs, 18 inch tire. I weigh about 200 lbs with gear. The larger tire diameter and the greater weight of the 18XL means that 20% more torque is needed to achieve the same amount of acceleration or braking as the V8F. The V8F has limited power and limited acceleration, but it brakes well. If the EUC frame is not rotating (forwards or backwards), then the torque the rider exerts onto the EUC is the same as the torque the motor exerts onto the wheel+tire. So I have to exert 20% more torque onto my 18XL as I do on my V8F to get the same rate of acceleration (limited by power), or more noticeably, when braking. 

Edited May 2 by rcgldr

[alcatraz]

Torque is at the axle, but commonly used as a measure of the force created at the contact patch.

[Timwheel]

I feel the discussion around torque and acceleration is always a bit strange. I've heard Hsiang say that the higher voltage of the lynx makes you able to acceleratewithout leaning as much and I absolutely don't understand why. To me, the only thing that makes the wheel accelerate is the fact that you make it lose balance. It can't accelerate if you don't lean, even if you have 10 000 volts. What makes a wheel feel zippy is more its lack of inertia (since the mass of the rotating assembly itself counteracts its acceleration) and how easy it is to produce a counteracting torque with your body (Pad set up and pedal positionning relative to your body shape).

A wheel that lets the pedals dip a bit will also help you, as it will use your weight leaning more as a mean to increase the torque you produce around the axle that enables the wheel to produce a counteracting force to balance it. That is where algorithm have a place, but it has nothing to do with power, it's just a PID thing that is more or less well done on any brand of wheels.
I feel for example that the medium or soft mode on my master is horrible, as it doesn't feel like an elastic but leans very slowly when you accelerate, which doesn't really help you to pick up speed. Soft mode on old veterans had a bit of instantaneous "give"on the pedals that made it feel zippy, like what you would do on the firmware of the v12 (which unfortunately made you able to cut out the wheel easily as it helped you "too much").

I feel like anything else is irrelevant

[rcgldr]

7 hours ago, Timwheel said:

I've heard Hsiang say that the higher voltage of the lynx makes you able to accelerate without leaning as much

A rider has to exert the same amount of torque onto the EUC that the motor exerts onto the wheel+tire, other than brief moments in a soft mode where some of the rider's torque is used to tilt the EUC. The lean angle of the rider relative to the pedals is what is needed for acceleration or braking (inverse tangent of acceleration or braking divided by 1 g) plus the lean angle needed to exert a torque equal to the motor's torque.

If not using power pads, lower pedals help generate more torque: the rider's horizontal reaction force to acceleration or braking is applied at the pedals, and with lower pedals, there is more distance from the main axle, and since torque = force x distance, that horizontal reaction force generates more torque with lower pedals. 

Another way to view this is that the angle from the center of mass of rider and EUC to the tire's contact patch is equal to the inverse tangent of acceleration or braking divided by 1 g, internal torques between rider and EUC don't affect this. Lowering the center of mass (lower pedals, bending at hips or knees), decreases the amount of lean angle relative to the pedals to achieve the same overall lean angle relative to the tire's contact path. 

If using pedals only, the center of force that the rider exerts onto the pedals can't go beyond the front or back edge of the pedals. If using power pads, the EUC exerts an opposing torque equal in magnitude to the torque the rider exerts onto the EUC via power pads and pedals, supporting the rider to allow the rider to lean further and apply more torque onto the EUC. With the rider's feet centered on the pedals, the rider's ankles are behind the center of the pedals, and power pads are setup so that the lower parts of the pads are back to line up with the riders ankles, and the upper parts are centered. Power pads restrict shin angle, so a rider has to bend at the hips or knees to compensate. 

 

Edited May 2 by rcgldr