Please help me understand Zero motorcycle gearing

[kYLEMtnCRUZr]

Zero motorcycles are capable of 0-60 in 4 seconds partly due to the huge pizza sized rear sprocket I assume. But what if I didn't care about that level of acceleration? Could I reduce the size of the rear sprocket to say 0-60 in 6 seconds and gain more range? Would this be bad or put a strain on the motor? My limited knowledge of electric motors has me wondering. Sure 0-60 in 4 seconds sounds like a blast, but for .01% of my commute, is it worth the sacrifice in range if any? The motor would be running at a lower rpm at any given speed with a more efficient (smaller) rear sprocket correct?

This is all theoretical so parts, warranty etc aside, though I am also curious if they make parts for this and if this would void any warranty.

Thanks!

[Daox]

Without knowing more info its hard to say for sure. But, based on what you've shared, I'd say you are not going to gain any range by regearing it. Electric motors usually prefer higher rpms. Higher rpms pull less amps. Electronics like pulling less amps as do batteries.

[jkv357]

I don't know that you will be able to alter the gearing, and as Daox noted, making the motor pull taller gearing may not give you any benefit. It may ever reduce the range.

You could talk to Zero and see what they say.

[2000mc]

Zero S Electric Motorcycle - Specs || ZERO MOTORCYCLES

For the '15 models at least, the zero sr is geared higher (top speed 102mph, 85 sustained) than the zero s (top speed 95mph, 80 sustained). When equipped with the same battery capacity, they claim the same range for either model for city, 55mph or 70mph

Also, with their belt drive, there may not be a third option avalible anywhere for higher gearing

[kYLEMtnCRUZr]

Well whatever they do I'm sure it's been through the wringer. But man their FX dirt model will not fair well in rock gardens with the belt/sprocket 4" from level ground! Would be a great place to advertise though. If I get one, I will fab up sprocket cover that reads "YOUR AD HERE!" Spins the correct direction to read from left to right too. 5 mph traffic in the passenger seat on my left hand side will get a kick. Oh wait passenger seats are always empty!

[kYLEMtnCRUZr]

Performance : Zero Motorcycles, Electric Motorcycle Company

/thread

Lolz

[ctrlburn]

Zero Sells alternative drive sprockets - for more torque and less range, so going the other way would help. They also sell chain drives for the FX (off road) so you needn't worry about rocks.

I can't vouch for aftermarket voiding warrantee but the speedometer is user programmable to modify the ratios so the speedo stays reasonably accurate.

Torque is torque - be it off the line or after 30 mph - so the smaller belt is not being preserved by less power off the line. The smaller belt is because no abuse from clutch dumping. The less power off the line is for control (or so I'm told).

They have bluetooth programmable "economy" settings which allows reducing overall torque, top speed and regeneration. Setting the torque down to 10% and it lumbers off the line like a moped. I programmed mine for less regenerative braking for use in the rain.

[veloman]

"Zero motorcycles are capable of 0-60 in 4 seconds partly due to the huge pizza sized rear sprocket I assume."
This statement makes a lot of assumptions. How do you know what the front sprocket size is? Vehicle top speed? Zero bikes are fast due to their battery and motor drive output. Gearing is how that power is translated. They would be faster 0-60mph if they were geared for 70mph instead of 80 or 100mph.


You have it backwards. If you gear it for a higher top speed, your efficiency is going to drop, and you will be stressing the motor more during getting up to speed.

If you are looking for best efficiency at top speed, then taller gearing may help a few %. But that is not real world usage. (90-100mph?) Terry Hershner changed to a slighter higher gear ratio, but that is because his goal is range at 70-80mph, AND he has a much lower load on his motor with the full streamlining.

Bottom line is that you want to gear your bike for the highest speed you will want to go, and NO HIGHER. Any gearing higher than what you will use is pure waste and loss in performance.

Electric motors do not work like ICE, where low rpm save fuel. Most electric motors are most efficiency around 80% of their top speed. So plan for that in your gear ratio.

On my converted motorcycle, I have it gearing limited to 66mph so if I ever need to use the freeway, I can. I actually rarely go over 50mph and avoid fast roads, so I would get better range and less motor heat if I geared it for 55mph. I spend a lot of time at 30-40mph.