Motorcycle class Hub Motor

[johnrobholmes]

The stator angle is still relative to the magnet width and winding scheme. If the magnet is wider than two teeth, then the skew is just fine. You could always get another made with 1/2 the skew and see how the cogging/ wattage/ and power figures came out too. What is the pole and slot count anyway?

 

[evmotorcycle.org]

I reckon an 18" rim would be about right for a Yamaha DT80LCII which is what I am thinking about converting. I have also checked other trail bikes such as YZ 250 and many of them are 18" rims.

 

[PaulM]

Generally speaking for fullsize bikes, trail/enduro bikes use 18 inch rims, motocross bikes use 19 inch.

Not really sure why there's a difference though . . . :?

 

[liveforphysics]

The stator angle is still relative to the magnet width and winding scheme. If the magnet is wider than two teeth, then the skew is just fine. You could always get another made with 1/2 the skew and see how the cogging/ wattage/ and power figures came out too. What is the pole and slot count anyway?

This motor retains identical magnet spacing and arc length with an X5 (If I read the thread correctly?). The magnets are just twice the width. Same arc length and spacing for the magnets with twice the angular displacement in radial skew of an X5.

The good thing is, it's a very simple matter to correct, and when you do, you will see less heat, more torque/power, and improved range! All very nice areas to make gains for such a simple manufactureing correction to make! It will be feeling even better than it all ready does, and it all ready seems to work well. Can't beat that!

Best Wishes,
-Luke

 

[markcycle]

Web page preview

http://www.doingitall.net/EnerTrac/index.php

Mark

 

[mrfechetto]

Hi Mark, I have a 1973 Yamaha TX500 for conversion and I would like to keep it as original as possible (minus engine/exhaust/etc). Would it be possible for you to mount this hub motor assembly to my current swingarm? Also, would that effect cost since you won't need to supply that part? I live nearby (~2.5hours) so I can drop it off and pick it up when you're done or I can do it myself if its simple enough.

 

[johnhead@frontiernet.net]

Mark,
I assume most of the "modern" bikes that you would be offering your hub-motor to would have cast rear wheels as stock? One concern that I would have would be rim/hub "offset". It may be assumed that the hub is always in the center of the wheel, BUT on many "older" motorcycles it was NOT the case. The Hub may be offset (IB to OB) by as much as .5-.75 inches? You may want to get some input from the perspective clients to see what thier bikes measure?
Just a HEADS up!
John Head

 

[markcycle]

Hi Mark, I have a 1973 Yamaha TX500 for conversion and I would like to keep it as original as possible (minus engine/exhaust/etc). Would it be possible for you to mount this hub motor assembly to my current swingarm? Also, would that effect cost since you won't need to supply that part? I live nearby (~2.5hours) so I can drop it off and pick it up when you're done or I can do it myself if its simple enough.

I think your a little confused I'm not selling a swingarm just a torque arm Swingarm not included and not offered.

Mark

 

[markcycle]

Mark,
I assume most of the "modern" bikes that you would be offering your hub-motor to would have cast rear wheels as stock? One concern that I would have would be rim/hub "offset". It may be assumed that the hub is always in the center of the wheel, BUT on many "older" motorcycles it was NOT the case. The Hub may be offset (IB to OB) by as much as .5-.75 inches? You may want to get some input from the perspective clients to see what thier bikes measure?
Just a HEADS up!
John Head

The motor I'm using is only 7.25 inches wide. Most swingarms are much wider than that, as such I will provide spacer as needed to center the tire/hub in the swing arm. Most motorcycles are 9 inches, some I measured are 9.5 inch spacing. The narrowest I measured is 7.5 inches, which is the Lifan I just converted as a demo bike. The key is to center the tire in the swingarm.

Mark

 

[Jay64]

Yeah, most modern sportbikes have different spacers on each side. You just have to have custom spacers made for your specific application.

 

[Lapwing]

The motor I'm using is only 7.25 inches wide. Most swingarms are much wider than that, as such I will provide spacer as needed to center the tire/hub in the swing arm. Most motorcycles are 9 inches, some I measured are 9.5 inch spacing. The narrowest I measured is 7.5 inches, which is the Lifan I just converted as a demo bike. The key is to center the tire in the swingarm.

That answers my primary concern.

Do you have any sense of the suspension dynamics of the hubmotor. Much different from before the upgrade to electric?

I would imagine the hub weight is noticable. I have recollections of my first old dirtbike with drum brakes in the rear and a pretty heavy hub/wheel. the dual shocks with minimal travel probably didn't help the handling. Suspension has come aong way.

 

[johnrobholmes]

I can imagine that removing the ICE and installing an electric kit would affect the CG, and thus the antisquat of the rig.

 

[Lapwing]

I can imagine that removing the ICE and installing an electric kit would affect the CG, and thus the antisquat of the rig.

No the CG will be similar, or perhaps lower, but the unsprung weight in the rear wheel will be somewhat more, hence my question regarding the bikes new dynamics on uneven pavement, compaired to the original.

 

[johnrobholmes]

The rear suspension will be more sluggish and it will track different, most certainly. Because the center of mass may be distributed along a wider area, maneuverability may go down. A lower CG would decrease the AS % of the rear suspension, as related to the old CG. So the rear suspension may be more prone to diving. The question is whether the ICE is heavier or lighter than the batteries and electronics that replace it on the frame, and how the weight distribution changes. Only the suspended weight is important with regards to antisquat.

 

[Jay64]

I really don't think it will be that big of a difference. The Buell motorcycles have the oil stored in the swingarm, so that is increasing the weight a bit. The Buell handles pretty good. They are winning races right now.

 

[johnhead@frontiernet.net]

Depending on the rear Brake "disc" mounting on the e-motor hub, you may also need to provide special spacings for the brake caliper once the rear tire has been spaced in the center of the swingarm. A minor issue I know, when looking at the grand scheme of this much anticipated grand wheel driving system...

 

[michaelplogue]

I could be wrong, but I think Mark mentioned integrating the brake mount on the torque arm - which I think is a great idea. This would preclude any additional frame mods needed to properly place the caliper - making it even more of a "one-size-fits-all" system.

 

[Jay64]

I know at the moment I'm showing more concept than product with this next drawing but I'm excited about it and wanted to share. I integrated the disc brake into the torque arm and made the motor and brake one unit. This will allow the motor to replace any wheel even on a bike that had drum brakes. The requirement is that the torque arm is properly connected to the rear swing arm.

Mark

 

[johnhead@frontiernet.net]

Ahh Thanks for the slap up side my "head" . I assume the price of the hub wheel will now also include the price of the caliper and brake disk.. ? If So I like it.....
Even less to engineer to apply to everyone's needs.
Hurrah for Mike!

 

[johnhead@frontiernet.net]

Er.. I meant Mark!

 

[JRP3]

I assume the price of the hub wheel will now also include the price of the caliper and brake disk.. ?

I doubt it, since many bikes will already have both.

 

[markcycle]

I assume the price of the hub wheel will now also include the price of the caliper and brake disk.. ?

I doubt it, since many bikes will already have both.

That's correct the wheel will not come with a caliper or rotor. I will provide a interface plate and mount the rotor for free (just give me the spacing needed and provide me with the rotor). The problem with the caliper is I can't assume the liability of a motorcycle brake system for every model of motorcycle one would want to convert. I'll provide as much technical support as I can to help one work out a drum brake to disc brake conversion, but in the end the owner of the bike needs to accept the responsibility for the braking system. I hope as time and experience with the hub motor builds I will be in a better position to recommend Rotor and caliper manufactures to use. What I did for the Lifan I built is, to use a salvage rotor and a dirt bike caliper to convert the bike. This works for a light bike maybe up to 350 pounds.

In the case of a motorcycle with rear disc brakes then this is not a problem. I looked into bikes like a Ninja 250 and the spread between the swing arm is 9 inches (motor is 7.25) so there is no problem keeping the original disc brake and mounting system. If your not comfortable doing a drum to disc conversion then choose a bike that has a rear disc brake.

Mark

 

[liveforphysics]

Nicely done mount Mark. I'm curious, do you find yourself using the rear brake much? With regen braking, does it often feel like you need more than the front braking effort and full regen when slowing down? Perhaps electricly braking the rear wheel could eliminate more complexity and lower costs and conversion efforts. I would assume just 2 large FETs setup to short the phases together under braking could provide more than enough braking to lock the wheel up, so a simple variable PWM signal to control the FETs that is dependent on the applied brake pressure could make a very clean, cheap and easy solution.

 

[markcycle]

Nicely done mount Mark. I'm curious, do you find yourself using the rear brake much? With regen braking, does it often feel like you need more than the front braking effort and full regen when slowing down? Perhaps electricly braking the rear wheel could eliminate more complexity and lower costs and conversion efforts. I would assume just 2 large FETs setup to short the phases together under braking could provide more than enough braking to lock the wheel up, so a simple variable PWM signal to control the FETs that is dependent on the applied brake pressure could make a very clean, cheap and easy solution.

Regen is really all you need except when your stopped on a steep hill or if regen fails. The way I have it setup is if you just touch the rear brake pedal it turn on regen at 10%, then on the left handle bar I have a thumb throttle wired to the variable regen input. and that allows one to add as much regen as needed. The rear disc brake is so I meet DOT standards and as a backup. The regen in the Kelly controller works well for the rear brake. If I want to lock up the rear brake I can use full regen plus the rear disc brake. I don't lock up the rear as I like to stay upright.

I wanted to add the front fork is crap and dives to much so I use more rear brake then I do on my Ninja 500R

Mark

 

[liveforphysics]

A good fork is very important for control. If you happen to get around to it, tear the fork down, and throw some spacer shims under the spring seats if the spring rate if too soft for the bike/rider setup. If dampening is too soft, run some heavier weight fork oil, and/or check to see if you can modify the orifice in the dampeners. Often time with a little brazing or a drill-bit, some cut-off pieces of 3/4" pipe (spring spacers), 2L of fork oil, and about 3hrs of time, you can transform a fork that feels like riding a noodle into something that gives solid and safe handling performance, and it didn't cost you more than $20 and a little time.

Best Wishes,
-Luke