Dual Pies

[Andrew]

Adding a Pie wheel up front. 
How easy is it to do?
how safe is it on the road?
can it be done on one GM 48v battery?
Would it be easy to disconect and just run one pie again?

If, for instance I bought a front pie wheel with internal controller, what else would I need?

Andrew

[DirtyGinge]

From what I understand from Gary at GMCANADA, its only a matter of splitting the black and white wires from the throttle, plus spliiting brakes, cruise control and whatever other controls you wish, but thats the basics, ( including power of course)

[Andrew]

that sounds promising. Lets wait and see what Gary has to say. I'd love to try it

[Bikemad]

Andrew, you might want to check out this post for more details.

It might be better to disconnect the throttle, rather than the battery, just to ensure that any generated voltage from the disconnected motor will always have somewhere safe to go.

You might have to use a double throw switch to swap between the throttle control signal and a fixed ~1V supply to prevent the disconnected Pie from going into throttle failure mode. This would be easy enough to do using a 2.2K and 10K resistor in series (or a single 10K pre-set variable resistor) connected between the +5V and 0V on the throttle.

If you used a double pole double throw switch, you could automatically disable the regen on the disconnected motor as well (if you preferred).

Alan
 

[Andrew]

Thanks Alan.   I've pretty much read the full thread, and from what you've said, do you believe there is no chance of an accident occuring if the motors runs at  differing speeds, or if say, one cuts out?

[Hardcore]

if one cuts out it will only create a little bit of drag, unless it cuts out like it get's stuck and won't turn again but that hasn't been reported here.

[MonkeyMagic]

At times with a quick press of ebrake to toggle cruise control sometimes one of my wheels keeps wanting to go. Easy enough to push the ebrake again...

Same thing with enabling cruise, now for each button I give them a longer press (about half a second) to make sure they both engage at once. Maybe I'm just too quick for the buttons sometimes lol

Hey Andrew, I don't think you will be disengaging one of the motors anyway. Once you have 2 you sorta don't go back!
+ you will probably find your power consumption to be the same if not better with the increase in efficiency

Just make sure you lower the regen% of each wheel before you ride it haha

[Andrew]

Hey Andrew, I don't think you will be disengaging one of the motors anyway. Once you have 2 you sorta don't go back!
+ you will probably find your power consumption to be the same if not better with the increase in efficiency

Just make sure you lower the regen% of each wheel before you ride it haha

Well, at the moment I don't have any regen, but i'm sure it becomes very important once two motors need to be stopped!  Plus, having two motors = two generators.... I suppose  


I will be adding regen again via one of the button controls.  I currently have the red button set for cruise control, if I unplug it at the wiring nest can I just use the same red button wire and plug to connect to the motor braking plug? and then have regen again? or am I missing something?

[Bikemad]

I currently have the red button set for cruise control, if I unplug it at the wiring nest can I just use the same red button wire and plug to connect to the motor braking plug? and then have regen again? or am I missing something?

Andrew,

If the plugs are the same (apart from the colour) then you can connect them without any problem.

I have my regen connected to the brake levers and also to the red on/off switch located on the throttle housing (I simply connected the two sets of wires in parallel) and I find it very useful, particularly when I'm walking the dog.
If I leave the regen switched On and then twist the throttle four times, the controller beeps and switches to brake switch failure mode. While in this mode, I can simply press the cruise button for instant half throttle, which enables me to easily ride around the field, using my left hand for brake, steering and throttle, keeping my right hand free to use the ball flinger for picking up and flinging the ball without stopping.

When I'm going down steep hills (at tired doggy speed) I leave the switch in the On position, which gives me permanent regen, and anti-lock braking on the rear as well. Sometimes I even pedal against the regen to go slightly faster just to keep my legs active.
 
I also make sure the switch is On and activate the brake switch failure mode before I set off downhill with a freshly charged battery. This automatically disables the regen and prevents it from overcharging an already full battery pack, which could be very dangerous for my Lithium Polymer battery pack!
Pressing the switch again at the bottom of the hill (back to the Off position) automatically returns the throttle and regen functions to normal.

I now intend to wire the unused horn button into the regen circuit as well, so that I can use the horn button for intermittent braking, instead of the continual pulling and releasing of the brake lever which I have to do quite a bit when the regen braking is too strong.

Alan
 

[Andrew]

Wow ,  seems like you've put plenty of thought into how to use the various controls you have at hand! I hope your dog appreciates it

You have (sort of) anticipated my next question....  On the two button control, is the red a 'switch' and the green(horn) just a button?  I guess so?    Which would mean that regen for me would be better if connected to the horn button, as I would not want to constantly activate/de-activate by clicking a switch.


just to add, I suppose it will be fine still keeping cruise on the red button whilst having regen on the horn? and does it matter what way around the wires connect at the plugs?

- always best to ask!

[Andrew]

Ok, I've done it!

What probably seems very simple to other members on here is truely a triumphant moment for me. 

Horn button now controls motor braking, and red button/switch still for cruise!! thanks to GM for including some spare pastic connecting plugs 

Andrew

[Bikemad]

I suppose it will be fine still keeping cruise on the red button whilst having regen on the horn? and does it matter what way around the wires connect at the plugs?

Andrew,

It sounds like you've already got it sorted, but for the sake of other members who may be considering something similar, the horn button works in exactly the same way as the cruise button, and it doesn't matter which way round the two wires are connected at the plug, because the switch simply completes a circuit between the two wires when it is pressed.

At least now you'll be able to test your anti-lock braking with all the slippery snow and ice we're currently experiencing in the UK. I had to go for a drive in the snow yesterday to get our Christmas tree, and I struggled in a few places trying to get home again, and getting my van back on the driveway was almost impossible. I ended up taking the Pie to work last night rather than risk getting stuck in the van again, but it was a lot of fun riding home on the snow and ice just after midnight.
Mind you, it must have been at least sixteen years since we've we had temperatures low enough here to actually burst a copper water pipe. (Yet another job I could have done without!)

Alan
 

[Andrew]

The South west certainly seems to have been hit with a white out. Here in S.Wales we got a good 12 inches of snow on friday over a 12 hour period.  my car has 4 wheel drive, but no number of driving wheels will ever get you anywhere without winter tyres on, something that is very alien to us Brits. I believe you have to have them by law in some northern european countries.

I'm not sure my Schwalbes semi slick 'balloon tyres' would be good in snow on my bike,, then again if I deflate them to about 20psi they maybe quite good.  I'd be tempted with some Schwalbe  metal spiked tyres if they weren't so expensive but I bet they turn any bike into a bone shaker on the road.

i tried to get to my local postal sorting office today to pickup a 7 speed freewheel with a small 11 tooth cog on the end which has arrived from the U.S.  i was turned back after half a mile due to lorry that was in danger of over turning on a hill.  The freewheel and gripshift will have to wait to monday

[MonkeyMagic]

Awesome I've been looking for something with teeth as few as 11 !
Can I ask where did you got it?

Hey also can you fit a 7 speed cluster on the wheel okay? I mean, should there not be any clearance issues, is there a maximum you can run on the pie?

For example, if somebody had a newer frame with 145mm dropouts, and used spacers past the cluster - would a 8spd+ fit?
Cheers

[Andrew]

i believe a 7 speed will fit. have a look here for the width of the DNP 7 speed freewheelhttp://endless-sphere.com/forums/viewtopic.php?f=2&t=18314&p=276576&hilit=dnp+freewheel#p276576

The DNP freewheel is 36mm wide
My shimano 6 speed is only about 3-4mm less.  

i got it from here.... http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=230554863188&ssPageName=STRK:MEWAX:IT   although it's from the U.S.  

I paid the company their international shipping fee, but my local postal sorting office is charging me for the postal fee not being paid,, so beware!  i will get more detail on monday over the charge and will be contacting the seller. I bet they only paid a domestic shipping fee, and then sent out to me.

Fortunately for me the exchange rate is always in my favour with the dollar


BTW, my bike originally had a 9 speed cassette, but I think it is a 135mm spacing.  8 speed and the pie might be pushing it. But maybe possible if you don't have disc brakes.