Putting rear gear hub motor to front?

[butters149]

Hi,

I am learning more and more by the day. I recently bought a leafbike 2000 watt direct drive brushless motor for my super 73 and plan to pair it with a 52 volt 14.8ah battery using LG HG2 cells. I originally thought that the direct drive 2000 watt with battery would be faster than the 500 watt geared motor using a 48v battery in my bike. What I want was fun because I live in the city so there are lots of stop and go's, and some inclines (although not many, but they are steep). Another mistake I did was when the manufacturer ask for the motor speed, I said 40 mph, which I thought would give me wiggle room if I ever needed it, this was a mistake because most of the time I am going 23-25 mph, way out of the "efficiency" zone of the DD. So is it possible to move my rear hub motor to the front if the drop outs are the same? I would probably have modify the front fork for the bigger axle. Thanks,

 

[RunForTheHills]

I wouldn't do it. You didn't really describe the bike you have. If the bike is a road bike less than 20 years old and not a fat bike, the O.L.D. of your front forks is likely 100mm and the rear is 135mm. 35mm is a lot to spread the fork (cold set) even if it doesn't have a suspension and is made out of steel.

https://www.sheldonbrown.com/frame-spacing.html

I am new to e bikes, but if the motor is not spec'd correctly for the type of riding you do, why do you want to keep it on the bike? It still won't be in it's efficiency zone if you move it to the front.

 

[amberwolf]

As long as your headtube is compatible with the steerer of one of them, you cna find a fatbike fork to hold a typical rear hubmotor.

That's the plan to put one on my SB Cruiser trike, to get 3WD plus regen braking up front.


I'd personally use the DD motor up front, so I could get the braking from it...but either one should have two good tight-fitting securely-mounted torque arms on it, so it can't destroy the dropouts of the fork and help your dentist with his savings account. (more likely to happen from alternating regen and acceleration than just acceleration, but can happen from either).

 

[Chalo]

Another mistake I did was when the manufacturer ask for the motor speed, I said 40 mph, which I thought would give me wiggle room if I ever needed it, this was a mistake because most of the time I am going 23-25 mph,

Yep, that was a critical mistake. If you want to cruise at 23 to 25mph, the free speed of the motor should be 30mph or so. The more powerful the motor system, the closer the free speed should be to the desired cruise speed.

 

[butters149]

I wouldn't do it. You didn't really describe the bike you have. If the bike is a road bike less than 20 years old and not a fat bike, the O.L.D. of your front forks is likely 100mm and the rear is 135mm. 35mm is a lot to spread the fork (cold set) even if it doesn't have a suspension and is made out of steel.

https://www.sheldonbrown.com/frame-spacing.html

I am new to e bikes, but if the motor is not spec'd correctly for the type of riding you do, why do you want to keep it on the bike? It still won't be in it's efficiency zone if you move it to the front.

super 73

 

[DAND214]

Hi,

I am learning more and more by the day. I recently bought a leafbike 2000 watt direct drive brushless motor for my super 73 and plan to pair it with a 52 volt 14.8ah battery using LG HG2 cells. I originally thought that the direct drive 2000 watt with battery would be faster than the 500 watt geared motor using a 48v battery in my bike. What I want was fun because I live in the city so there are lots of stop and go's, and some inclines (although not many, but they are steep). Another mistake I did was when the manufacturer ask for the motor speed, I said 40 mph, which I thought would give me wiggle room if I ever needed it, this was a mistake because most of the time I am going 23-25 mph, way out of the "efficiency" zone of the DD. So is it possible to move my rear hub motor to the front if the drop outs are the same? I would probably have modify the front fork for the bigger axle. Thanks,

Confused? Are you saying that you want to put a GEARED hub on the front or the DD in the front with the Geared in the rear? Or just put the 2000w motor in front with no rear motor? First, I would never put that kind of power up front, even with the best Torque arms made. If the bike is a fat bike the hub should fit the front but I still wouldn't try it.

So what that it's out of it's best efficiency, pedal it hard from stops. Have you tried it yet or just thinking that you bought the wrong motor?

Dan

 

[butters149]

Hi,

I am learning more and more by the day. I recently bought a leafbike 2000 watt direct drive brushless motor for my super 73 and plan to pair it with a 52 volt 14.8ah battery using LG HG2 cells. I originally thought that the direct drive 2000 watt with battery would be faster than the 500 watt geared motor using a 48v battery in my bike. What I want was fun because I live in the city so there are lots of stop and go's, and some inclines (although not many, but they are steep). Another mistake I did was when the manufacturer ask for the motor speed, I said 40 mph, which I thought would give me wiggle room if I ever needed it, this was a mistake because most of the time I am going 23-25 mph, way out of the "efficiency" zone of the DD. So is it possible to move my rear hub motor to the front if the drop outs are the same? I would probably have modify the front fork for the bigger axle. Thanks,

Confused? Are you saying that you want to put a GEARED hub on the front or the DD in the front with the Geared in the rear? Or just put the 2000w motor in front with no rear motor? First, I would never put that kind of power up front, even with the best Torque arms made. If the bike is a fat bike the hub should fit the front but I still wouldn't try it.

So what that it's out of it's best efficiency, pedal it hard from stops. Have you tried it yet or just thinking that you bought the wrong motor?

Dan

I want to put the DD 2000 watt in the rear since I already bought it spec'd for the rear fork. My front fork is only about 138mm dropout, I would need to find a geared hub motor for that, ideally I would use that with a seperate controller and throttle hooked to the same battery, it would be used for takeoff acceleration ONLY.

 

[dogman dan]

Its not impossible to put that geared motor up front, it should be able to fit once you get the freewheel off it. It will not be centered right though, so you might have to do some fiddling around with spacer washers to get close, the change the dish of the wheel.

IMO, more pain in the ass than worth it.

You are not getting poor efficiency at 23 mph, with a 40 mph motor, unless you are overloaded and going up hills. You do get less efficient starts with the DD motor, especially if you romp the throttle at the starts.

Stop worrying about your efficiency if your desire is for the ride to be fun. Fun accelerations are never efficient. Concentrate instead on a battery that can handle your 2000w setup. Then you can have yer fun, without caring about efficiency so much. If your 2000w setup is not faster than your 500w, the reason why is your battery is squealing like a pig, as you kill it.

 

[butters149]

Its not impossible to put that geared motor up front, it should be able to fit once you get the freewheel off it. It will not be centered right though, so you might have to do some fiddling around with spacer washers to get close, the change the dish of the wheel.

IMO, more pain in the ass than worth it.

You are not getting poor efficiency at 23 mph, with a 40 mph motor, unless you are overloaded and going up hills. You do get less efficient starts with the DD motor, especially if you romp the throttle at the starts.

Stop worrying about your efficiency if your desire is for the ride to be fun. Fun accelerations are never efficient. Concentrate instead on a battery that can handle your 2000w setup. Then you can have yer fun, without caring about efficiency so much. If your 2000w setup is not faster than your 500w, the reason why is your battery is squealing like a pig, as you kill it.

my battery is a 52 volt, 14.8 ah with LG HG2 cells. good enough? And I would be comfy at 30 mph actually.

 

[2old]

Initially you wanted more torque than the 500w stock motor provided. The Leaf should suffice. Since your rear dropouts are 170 mm, doubt you'll be able to fit that motor in the 138 mm front and have it dished adequately. Since you're in socal as well as Super 73, did you ask them about converting your bike into one of their more powerful models or trade up?