Nanny's bike: Overvolted Zap! Friction Drive

[GCinDC]

I got this off craigslist for nothing. Was thinking if nothing else I could sell the battery support! The 12V SLA battery worked but was a little sluggish, so I removed the 15lb lug, and put in a little lipo and wow how she flew! And so lightweight. Very quiet too.

Was about to get pics and vid, but the rear derailleur got trashed (musta been why it was a giveaway). But here are pics of the similar model:

The kit:

Seems to be no longer in production. Can understand why at that price...

Anybody else have one of these?

Pics and vid to come.

 

[EVTodd]

Don't have one but I'm interested. Does the zap drive pivot on and off the tire?

 

[tritonwow]

Don't have one but I'm interested. Does the zap drive pivot on and off the tire?

It does. It has a little arm to mechanically move the roller onto the tire when your ready to use it.
I don't have it on hand though to reexamine the unit. I picked one up a few months back while in AZ (single motor type) and gave it to my dad. I think he's not going to use it so I'm getting ready to tell him to ship it back to me.

 

[GCinDC]

[youtube]5cSI6oWc5dw[/youtube]

 

[beast775]

getting private video message? ha dang computers. lucky ebikes arent this difficult.

 

[GCinDC]

OK. made it public. sorry bout that!

 

[etard]

Very cool, never even heard of that one! Gotta give love to CL, $500 new is ridiculous, $50 on CL and you got a freind to ride with. Is there any roller slip with the Lipo?

 

[GCinDC]

..$50 on CL and you got a freind to ride with. Is there any roller slip with the Lipo?

it was actually a freebie! needed work as i soon found out, and guy didn't feel right selling something in that condition, or paying to get it fixed.

i thought i'd keep only the battery mount, as the design is perfect for the triangle and very stable.

you know, i don't think there is a lot of slip. but it must, on that hill. either that or it clamps so well to the wheel that it doesn't.

another thing, it's perfectly silent. not a sound. and SO LIGHT!

 

[GCinDC]

thought my CA was visible in the vid. top speed on the slight incline: 15mph. never measured on the flat, but faster downhill. 6mph up a STEEP hill. i'm guessing the motor won't take that long...

 

[etard]

HAHA!! That's the lamest video you've ever made Greg!! :lol: :lol:

Is it 2 motors? What did you overvolt it to?

 

[liveforphysics]

I bet that simple light little drive is just enough for a lot of folks to commute with a bike that wouldn't otherwise. Just the damn crap performance of the lead acid was holding it back, and you totally solved that problem!

I love the LiPo upgrade!

 

[GCinDC]

HAHA!! That's the lamest video you've ever made Greg!! :lol: :lol:

You must not have seen this one I just did, the truly lamest vid of the lamest BionX w/ extended lipo ever:
[youtube]eHQIdPooc3Y[/youtube]

Is it 2 motors? What did you overvolt it to?

Now, come on, you gotta watch it... :lol: It's one little friction drive motor. orginally 12V SLA, 10lbs? replaced w/ 5s 18.5V lipo 1.5lb?

 

[GCinDC]

BTW, how much voltage/amps do you think it can take?

i wonder about replacing the motor...

i guess to go faster it might need a proper accelerator, rather than an on/off trigger!

 

[GCinDC]

tossed an old turnigy 5s2p pack on the Zap! bike. was quite surprised to see the motor was drawing max 84A!
[youtube]SxUmS74HtK0[/youtube]

it was an old, slightly puffy, but balanced pack. originally 10Ah, now 5Ah. i took that vid after the buzzers first beeped (set to 3.3V). i was quite hot too, so probably not that safe anymore.

ps. thing is peppy at 20V. could SLA serve up 84A? or must there have been a limiter of some sort on/in the old batt? any simple way to limit the current?

 

[GCinDC]

need suggestions about getting this thing going. gotta be safe and reliable with the son on board.

i'd consider lipo, but i don't want to keep a lipo buzzer on it all the time draining current, and sucking 80A w/o a bms, the batt will drain in no time, and one accidental drain could make it very dangerous...

so i've got an old 48V 12Ah ping battery, that has only 8 good cell groups on it, so i'm wondering - should i:

- make a 24Ah 12V(4s) pack to service the zap friction drive?

OR

- make a 24V(8s) 12Ah pack and toss a 6x10 9C, along w/ my original 48V controller and a throttle...?

obviously i have to figure out if the 48V controller (orig w/ GM kit) has an lvc setting. don't think it's programmable...

will the friction drive kill the lifepo4? was the original SLA so much more resilient to current demand?

the friction would be easiest, since it's only on/off trigger throttle, no controller, etc and should provide just enough help, but if a kid's on the back, it might get bogged down.

but i'm not sure a 24V 9C would do much better...

again, this is actually a nanny's bike so a top speed of 15mph is just fine...

i've been meaning on doing something with this lifepo4 for ages, but think i pretty much will have to yank the bms and run it w/o one... bad idea?

thanks for any suggestions...

 

[GCinDC]

going 5s2p10ah lipo, told her to use it intermittenly as it pulls 40A continuous and i don't want it getting too hot. working great tho:

can someone tell me why this motor is dead silent and rc motors sound like dental drills? (no offense)

 

[GCinDC]

bike was riding fine, according to the 'nanny', up until i recharged it the other day. after recharge and reconnecting the battery, it no longer worked.

5s2p pack at 20.8V
turnigy watt meter operational.
andersons on output side of watt meter not sunken or melted. measure 20.8V
(brushed?) motor runs when 12V applied directly to +/- on it's connector (and is lifted out of position)
so it's gotta be:
- the throttle
- the wiring between watt meter and motor
- the controller (lousy pic)

i measured 20V coming into the controller.

do i even need that controller? since it's an on/off throttle... could i just bypass it?

 

[kfong]

Looks like just a relay board so that the switch doesn't get burned out from the current. The relay might of fused the contacts together, but that would leave it full on. Is there a fuse? Looks like a simple DC motor setup. Most dc motors are quiet since the are mainly built like in runners and are fully housed.

Greg, I could modify my smart switch so it acts like a on/off switch if you want something more reliable than an overvolted relay.

 

[GCinDC]

thanks, kfong. it actually turned out to be a broken solder joint on the throttle momentary switch:

 

[GCinDC]

cleaned it up a bit. this is a great setup. super light, quiet, no nonsense:
[youtube]s8iJosMckyo[/youtube]

 

[GCinDC]

i could totally fit the lipos and the relay board inside the container that's worm clamped to the frame:

it's just got a plastic bottom to the battery that sits snug under the inner pads:

and the momentary switch back in the trigger switch:

how much would this cost to recreate? pretty kiss

 

[kfong]

Friction drives are pretty darn simple, I plan on putting one on my nieces bike one day. Something similiar to a kepler setup. Just have to find something safer than lipo's for them but fairly compact.

 

[GCinDC]

the momentary switch mechanism broke again.

so i fired up another from radio shack and did some mods to make it work:

unwittingly, i'd bought the switch that is 'normally closed' instead of 'normally open'.