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[motorrad36]

A comment in the below EMF thread got me thinking.

https://www.electricmotorcycleforum.com/boards/index.php?topic=6121.msg46702#msg46702

Would it be possible to charge a zero while being towed behind a vehicle using a front wheel chock towing attachment?

https://theusatrailerstore.com/the-original-slick-wheelie-motorcycle-hauler/

would it stress the belt too much, or create too much heat? my reason for thinking about this is like a poor mans charge tank. I would love to take much longer trips, but do not want to sacrifice the tank storage for a power tank. Would also love to get a 9.9kW diginow, but those are rare and a pretty penny. Im positive I could strap this down in some weird way on the back of the bike to make it both safe and stable. Only necessary to be used on long trips, when low on charge and a distance from a plug/safe place to charge. So, attach to a capable vehicle, drive for a while in the direction I'm already going, remove from truck, re-strap to bike, and i'm on my merry way. Yes, very unwieldy. And, it would be up to me to nicely ask the right person and get lucky when they agree to tow me. Buuuut in theory...it could work right?

[togo]

A comment in the below EMF thread got me thinking.

https://www.electricmotorcycleforum.com/boards/index.php?topic=6121.msg46702#msg46702

Would it be possible to charge a zero while being towed behind a vehicle using a front wheel chock towing attachment?

https://theusatrailerstore.com/the-original-slick-wheelie-motorcycle-hauler/

would it stress the belt too much, or create too much heat? my reason for thinking about this is like a poor mans charge tank. I would love to take much longer trips, but do not want to sacrifice the tank storage for a power tank. Would also love to get a 9.9kW diginow, but those are rare and a pretty penny. Im positive I could strap this down in some weird way on the back of the bike to make it both safe and stable. Only necessary to be used on long trips, when low on charge and a distance from a plug/safe place to charge. So, attach to a capable vehicle, drive for a while in the direction I'm already going, remove from truck, re-strap to bike, and i'm on my merry way. Yes, very unwieldy. And, it would be up to me to nicely ask the right person and get lucky when they agree to tow me. Buuuut in theory...it could work right?

I've done it.  I towed my 14 SR Zero, held by front wheel, from California to Arizona, and with key-on and throttle-off regen set to max, it did charge.

I will say I can't advise it, and I will not do it the same way again.  The device that holds front the wheel up is kind of sketch, and the motorcycle will tilt very alarmingly when you make turns, put a lot of stress on it.  And if you worry about clearance, and get a riser to lift the motorcycle up more, it will actually tilt all the way to where it drags when you turn.  That's the geometry of using the motorcycle's own pivot for the tow.

I kept the rear-view camera on the entire trip, and I'm glad I did.

Now, if I could find a version of the tow gadget that was less sketch, one that had its own pivot and kept the motorcycle upright through turns, maybe I'd do it again.

[TheRan]

I don't see why it wouldn't work, the bike's only going to regen at the same rate as if you were coasting down hill. I don't know what that rate is or how it compares to charging regularly though, whether it's enough to actually bother with. As for the belt, whatever the rate of regen is it's going to be a lot less than what the motor can put through the belt when driving the bike forward (30-50kW depending on the model, the theoretical max on regen is the same as the battery capacity i.e. 7.2/14.4kW).

If it turns out that regen is much higher than the stock charger one of those tyre spinners that they use to start ICE bikes without a starter motor (race bikes) would make a great fast charger, although not exactly environmentally friendly.

[motorrad36]

A comment in the below EMF thread got me thinking.

https://www.electricmotorcycleforum.com/boards/index.php?topic=6121.msg46702#msg46702

Would it be possible to charge a zero while being towed behind a vehicle using a front wheel chock towing attachment?

https://theusatrailerstore.com/the-original-slick-wheelie-motorcycle-hauler/

would it stress the belt too much, or create too much heat? my reason for thinking about this is like a poor mans charge tank. I would love to take much longer trips, but do not want to sacrifice the tank storage for a power tank. Would also love to get a 9.9kW diginow, but those are rare and a pretty penny. Im positive I could strap this down in some weird way on the back of the bike to make it both safe and stable. Only necessary to be used on long trips, when low on charge and a distance from a plug/safe place to charge. So, attach to a capable vehicle, drive for a while in the direction I'm already going, remove from truck, re-strap to bike, and i'm on my merry way. Yes, very unwieldy. And, it would be up to me to nicely ask the right person and get lucky when they agree to tow me. Buuuut in theory...it could work right?

I've done it.  I towed my 14 SR Zero, held by front wheel, from California to Arizona, and with key-on and throttle-off regen set to max, it did charge.

I will say I can't advise it, and I will not do it the same way again.  The device that holds front the wheel up is kind of sketch, and the motorcycle will tilt very alarmingly when you make turns, put a lot of stress on it.  And if you worry about clearance, and get a riser to lift the motorcycle up more, it will actually tilt all the way to where it drags when you turn.  That's the geometry of using the motorcycle's own pivot for the tow.

I kept the rear-view camera on the entire trip, and I'm glad I did.

Now, if I could find a version of the tow gadget that was less sketch, one that had its own pivot and kept the motorcycle upright through turns, maybe I'd do it again.

I've read a few posts about that exact issue. I think that is endemic to certain constructions of front-wheel tow rigs. I am currently trying to find one that doesn't allow the tilt.

I don't see why it wouldn't work, the bike's only going to regen at the same rate as if you were coasting down hill. I don't know what that rate is or how it compares to charging regularly though, whether it's enough to actually bother with.

my anecdotal evidence tells me that I get about .1% back every time i coast to a stop from about 25 mph. so at a sustained 65-ish mph I would imagine it could actually be pretty quick...

quick mafs: .1% regen for every 150ft at 25mph(peak) means at 25mph youd need 150,00-160,000 feet get to 100%? lets say the regen maxes out at whatever the rate is at 30mph (I do not know if this is what happens), you'd need to go around 30-35 miles being towed. That doesn't even sound unreasonable actually.

[TheRan]

Your mention of speed reminded me that there's a speed limit for regen and when trying to find out what that was (75mph) I found this thread: https://electricmotorcycleforum.com/boards/index.php?topic=4357 Apparently the max regen is 40A or about 4kW so quite a bit more than the stock charger, and can potentially be increased.

[togo]

My understanding is that the sevcon controller can be programmed for about 10X what zero calls 100% and that they chose the level they did so you wouldn't be freaked out lose rear wheel traction when activating it.

[motorrad36]

Your mention of speed reminded me that there's a speed limit for regen and when trying to find out what that was (75mph) I found this thread: https://electricmotorcycleforum.com/boards/index.php?topic=4357 Apparently the max regen is 40A or about 4kW so quite a bit more than the stock charger, and can potentially be increased.

What an interesting thread!!

[ieism]

My first thought is the charger could overheat because it's not meant to charge that fast without breaks to cool down. But I'm interested if this works.

I actually bought a carrier for my bike to take it on roadtrips. It holds the front wheel preety solid so I could probably modify it to tow the bike if it needs charging and I'm nowhere near an outlet when camping.

[TheRan]

My first thought is the charger could overheat because it's not meant to charge that fast without breaks to cool down. But I'm interested if this works.

It wouldn't be using the charger at all. The charger provides a connection from mains electricity to the battery (and connects to the MBB for communication), charging by towing would use the motor to provide the electricity which would go to the motor controller and then to the battery. In theory you could use it to charge the battery if you had a busted charger.

[motorrad36]

If the motor is 76 nM, or somewhere near there, does that mean it needs 76nM to turn the wheel once?

[TheRan]

If the motor is 76 nM, or somewhere near there, does that mean it needs 76nM to turn the wheel once?

The torque number listed in the specs is the maximum that the motor can produce, the torque at the wheel is higher due to the gearing change. However, that's when you're pumping many tens of kilowatts through the motor, regen is going to be producing roughly a tenth of the power so it'll take significantly less torque to turn the wheel.

[motorrad36]

Right that makes sense. Now I’m thinking how cool it would be to charge a bike via human power. Like rig up something like a dynamo on a bike or a stair master. Use that to turn the rear wheel.

[domingo3]

Right that makes sense. Now I’m thinking how cool it would be to charge a bike via human power. Like rig up something like a dynamo on a bike or a stair master. Use that to turn the rear wheel.

I think it would be more of a novelty than reality.   Back-of-thr-envelope calculation says it would take a week of 12 hour days on a treadmill to charge the bike from empty.. 

[ESokoloff]

Right that makes sense. Now I’m thinking how cool it would be to charge a bike via human power. Like rig up something like a dynamo on a bike or a stair master. Use that to turn the rear wheel.

I think it would be more of a novelty than reality.   Back-of-thr-envelope calculation says it would take a week of 12 hour days on a treadmill to charge the bike from empty..

I think it would take Much more then that ....... https://en.wikipedia.org/wiki/Human_power

[motorrad36]

Right that makes sense. Now I’m thinking how cool it would be to charge a bike via human power. Like rig up something like a dynamo on a bike or a stair master. Use that to turn the rear wheel.

I think it would be more of a novelty than reality.   Back-of-thr-envelope calculation says it would take a week of 12 hour days on a treadmill to charge the bike from empty..

Ahh haha yes I think it would take quite a bit longer. I really just meant for like a quick workout. Might as well get something extra from it if possible!  But I do realize it would be an unreasonable amount if time.