folding ebike solution

[Garm@n]

Gary do these kits come with a kill switch.  Personal safety if throttle sticks.  I know the battery casing has a key lock,  I am presuming it's off/on, but impractical if it's behind me and low to the back wheel.  Would be difficult to turn key if something goes wrong.  Also once I choose the 48volt kit, would it still be possible to use 36v SLA battery as back up or during building phase to test motor and controller or is it just best to buy the battery with the kit.  Thanks

[GM Canada]

The brake levers have a wire to the controller that cuts the power and enables regenerative braking. Any 24, 36 or 48 volt battery will run the kit. The higher the voltage the more power and speed. If you are thinking of using cheaper batteries until you can afford something better you are not the first person to do this. Many people have started out that way. I have even seen some people using two or three old car batteries in a trailer to get started. That maybe a bit much for you and your folding bike though

Gary

[Garm@n]

You mentioned something interesting.  Once the hand brake is engaged the motor stops rotating, regardless of the throttle position.  Right now the setup for my folding bike will be...
1 front wheel mp3 hub (16")
2 rear coaster brakes
3 front v brakes
4 eventually 48v LifePo4 battery
My questions are... 
-the kit I buy will have 2 hand brakes I will only need one due to the rear coaster brakes.  Problem?
-the front v brakes.  Will the motor cut-off  still engage or do I need disk brakes? regen braking also work with V brakes?
-will I be able to connect the new brake handles to my current braking system? (ie front v brakes)

BTW how water tight are these systems

[Leslie]

Hi.  And Hello Gary.

I believe those charts include newton torque test readings with RPM and efficiency load voltage, for a 26" wheel.

I guess it was a tread mill setup.  So the 12" should experience less torque at high RPM and wind up faster on load.

I think speed drops off with the 12" diameters a tad, more voltage 48v or higher can satisfy that and program your bike to go what ever speed you need.

[GM Canada]

You mentioned something interesting.  Once the hand brake is engaged the motor stops rotating, regardless of the throttle position.  Right now the setup for my folding bike will be...
1 front wheel MP III hub (16")
2 rear coaster brakes
3 front v brakes
4 eventually 48v LifePo4 battery
My questions are... 
-the kit I buy will have 2 hand brakes I will only need one due to the rear coaster brakes.  Problem?
-the front v brakes.  Will the motor cut-off  still engage or do I need disk brakes? regen braking also work with V brakes?
-will I be able to connect the new brake handles to my current braking system? (ie front v brakes)

BTW how water tight are these systems

One hand brake is fine as long as you use it when you brake so it cuts the motor.

Regen braking works with v-brakes, disk Brakes, etc

To use the brakes. you just unclip your brake cable from you exiting brake lever. Replace the brake lever with the gm one and join the brake cable to it.

The internal controllers are fairly water proof as long as the motor is mounted correctly with the cable running water away from the motor instead of into it.

With the external controller wheels there are less water issues as the controller can be protected from water quite easily.

The main water issue seems to be when people seal the motor air tight casing condensation to be trapped inside.

Are you sure a 16 inch will fit on your bike? If so I have a front MP2 16 inch with external controller I'm selling used. Contact me by email if you are interested.

Gary

[OzGeeksGarage]

Be careful with the axle width, I've just gone through making custom forks because I couldn't get 20" forks that were wide enough to take the Smart Pie, if you're just looking for a folding electric bike, I'd skip all hassle and buy one complete.

As far as speed goes if people are getting 40kph out of 26" wheels, then being a smaller wheel you're going to be maybe half that, because every rpm covers less distance, on the plus side if you halve your speed, you should have double the torque. I just took my 20" Smart Pie Trike out on the road for it's first run, and with only 1 20AH 24V LIPO4 Battery I estimate I'm getting around 20kph, not bad with a 130kg rider, it won't go up my 15 degree driveway, but I just have to use the pedals And I'm still waiting on the second battery to give it a go at 48v. I haven't hooked up the laptop and fiddled with anything yet, got to try the Pedal assist yet.

Hopefully get some pics tommorrow, maybe some video.

[Garm@n]

Hey thanks for the advice.  Since you are doubling the voltage would it not be correct that the rpm will double as well giving you 40km/h base on a 20' wheel.  Also I'm speculating the 48v is really 58V giving you another 5-6km/h.  So possibly your 20" bike can go about 45km/h and based on that figure and applying to a 16" wheel I would do about 35km/h or am I wishing these figures.  Plus I weight 170lbs or 77Kg.

The odd thing I remember is reading the specs and when calculating the speed via rpm I was unimpressed with the speed achieved.  20Km/h is too slow for my liking. 32 is my limit for speed. I'm getting mixed messages, But I am curious as to how the Emmo urban is able to achieve speeds up to 40Km/h on 16" wheels and no mods.  I think that is the size I read previously.

-Gary, about the 16" MP2 or MP3 I sourced out a 16" bike do you know how wide the axle width for mp2 or 3.  Also can you tell me the difference between2 and 3.

[OzGeeksGarage]

Well I don't think double voltage means double speed, more like some speed & extra torque & range, I'm only expecting an extra 50% at best. It's also possible I'm badly estimating my speed and only doing 15kph too.

Here's some rough calcs on the circumference of the rims using pi*diameter

16" = 127cm per revolution = 67% of 40kph = 27kph
20" = 159cm per revolution = 84% of 40kph = 33kph
26" = 188cm per revolution = 100% 0f 40kph

So my guess at half the speed is incorrect, more like I've lost only 15%, this is off the rim size so there's probably a bit more speed with another 4 inches of tyre added. So if I'm right the best speed you can get is 67% of what the guys with 26" wheels are getting, but you may have 33% more torque for climbing hills

I'm not sure my trike is stable enough to want much more speed anyway, I need to lower it's centre of gravity a lot, not being able to change the lean of the bike for corners and road camber feels weird

[Garm@n]

Thanks again.  I'm looking forward to see your trike build.  I'm actually considering buying the bike whole as I will be in Florida in March.  Do you know of any good stores that sell folding e-bikes in Tampa Florida or north of that location.

[GM Canada]

Be careful with the axle width, I've just gone through making custom forks because I couldn't get 20" forks that were wide enough to take the Smart Pie

The Smart Pie axle width is 100mm front and 135mm rear. That is the same as all other kits I sell and is pretty much standard on 99 percent of all bikes made worldwide. I find it puzzling that you could not find 20 inch forks with the 100mm width. Or Is it because you have a folding bike and could not find standard 20 inch forks that would fit your bike?

Gary

[OzGeeksGarage]

My original Trike forks were only around 90mm wide like a dragster bike with a 1" neck tube, my old mountain bike has the same width and 1" neck too. I looked and to find a 1" necktube 20" or even 26" forks 100mm wide with Disc brake mounting just weren't around at the local bike shops or the internet, I had also already brought a set of 26" forks with the wrong necktube so all I could do was cut n shut the 1" neck onto the 100mm wide forks. I wanted a chopper look hence the longer forks
It was just something I had never considered when starting the project that there was more than one size neck tube or front axle width. Now it's operational, hopefully I'll take it for it's first shopping run and get some picks of it on Monday if the sun comes out

[GM Canada]

Both of those bikes must be old standards or unusual bikes. Here is a few modern day references.

Wikipedia states standard front forks 100 mm and 110mm on downhill bikes. My downhill bike was 100 mm front forks.
http://en.wikipedia.org/wiki/Bicycle_fork

Sheldon Brown states 100 mm front for modern bikes and a whole variety of sizes for rear wheels. But do you believe a guy with a gold bird on his helmet?
http://sheldonbrown.com/gloss_sp-ss.html

Gary