Endless Sphere

The threads for the pedal hole are left hand on the left crank, and right hand on the right crank. Putting the wrong one on the wrong side makes the pedal unscrew while you're riding until it gets unscrewed enough to rip out the final few threads, ruining the crank. That's how it signifies :thumb: :D

I went with a 55 tooth. Very pleasant at 28-33ish. Just took grinding some plastic of the battery case, and a little sledgehammering to flatten the frame behind it a bit. 😉 IMG_20190222_122105.jpg The 175mm cranks give you some leverage too... a couple of weeks ago I actually broke one of those blac...

Drag that goes away when unplugged is usually on the way from the motor to the controller somewhere. If you're lucky, maybe the phase wires melted a little and are shorting, so if that is it sometimes the controller still works after fixing the wires. Next is maybe blown component in the controller....

Or you stirred up crud at the bottom that's been shed off the plates, and it's internally shorting. Also, did you use a hydrometer on it yet?

Is it the left or the right? It matters a bunch...

You may never find a brand.. lots of those get made and sold under some random name that keeps changing. But that one is your basic really really cheap fat bike. Steel, easy to bend cranks, the lowest grade cable disc brake (that can be hard to find pads for), three piece steel stamped together hubs..

And re the balance taps, I would say they're essential for either... But they are themselves a potential source of short circuits if not done right. I think you would be surprised by the extended life of a sla pack actually kept in balance. It's great practice anyway before stepping into a split lit...

The switching to lithium plan maybe depends on how much the pack is going to be checked by someone. Lithium is much more dangerous, especially when you get into multiple split packs. It creates more ways to have overcharging and undercharging going on, maybe at the same time across the pack, both of...

https://endless-sphere.com/forums/viewtopic.php?f=14&t=102289&start=50 This guy built his own balance leads coming from the batteries so he could check and charge them without opening up the body panels on his scooter. WhatsApp Image 2019-09-20 at 14.01.06.jpeg WhatsApp Image 2019-09-20 at 13.58.38....

They make LiFePo chemistry lithium batteries that are a drop in replacement for 12v sealed lead. The lithium ion phosphate chemistry runs at a different voltage that regular lithium, that is close enough to less acid voltage to work. It didn't have the energy density of regular lithium, but way bett...

If it was taped to the side, and had two wires, it was almost def a temp sensor. For ni-cad in particular, the battery temp was important for the charging algorithm.

I'd wager it would need about 4 or 5 in parallel to not sag too much.
And have you actually metered the amp draw during acceleration? I was surprised to find my 20 amp rated controller was pulling close to 40 amps briefly during pullouts.

There's a nice YouTube vid of a guy cutting ripoff cells open, and inside was a tiny lithium battery wired in to make voltage... Packed in with enough ballast to make it about the right weight.

Don't know what your test bench setup is, but if you bolt it into a frame or a bench mount jig, then use a laser tachometer to get the rpms, you could figure out the kv (rpms/volt) and see if matches a spec sheet, before going to the trouble of lacing it up. images (6).jpeg They're like 10 or 20 buc...

Every time I've seen a motor do a partial turn and then stop it's been Hall sensor related. Either one burned out, or a wire got pinched. If you know how to use a volt meter, and have steady hands or an assistant, and you can get at the Hall wires plug, there should be 5ish volts on the red and blac...

That makes more sense

The OP didn't say exactly why he wanted to go 72v, but if it's to get more rpm out of his motor, more ah won't help.

And his 36v packs are 12ah, so not sure how a 9-10ah one will help?

They sell front and rear lights that also have a camera built into them... There's lots of cynicism about whether anybody will do anything, but if it catches even one dumbass angry driver purposely hitting someone and leaving them unconscious or dead with no evidence, I'm all for it.

Another plus is charging, 36v chargers are cheap and easy to get. And if you're in a hurry, easy to drop the time by running a charger to each sub pack. This was for 2 modules.... But I did spend a good bit of time tweaking the chargers to get exactly matching voltage cutoff, so the sub packs would ...

Like stated already, maybe, depending on the BMS. But the concept is just fine... I run several 36v doubled up packs. It's a great way to give 72v to a motor that could use some more volts for some more rpms with cheap, easy to get batteries and chargers. Now 72v is getting more available commercial...

Full suspension and rear racks don't always go well together... And for actual off-road riding, having the battery weight that high and that far back really really kills the handling...

This is the kind of bike the OP was talking about btw.

so much for stealth 8-) Yeah, there's no hiding that freakshow. But the ride is so fast and perfectly balanced that my eyes are glued forward and I forget real fast how it looks 👍 XShgunSoW5o Feel free to skip ahead if you don't love hypnotic back and forth s turns as much as I do, but the final mi...

Then there's this one for weekend fun... Modified Yuba Mundo cargo bike frame. That one is fuuuuunnn.

The motor size is really the same... It's more of a controller side thing. My main ride is a recycled EV Global with modern battery, controller and motor... A giant plus was the dropouts are already deep enough for an ebike axle. IMG_20190222_122105.jpg That bike was made in 1998... That frame will ...

Spine protector batteries are going to be a big market I think.. I personally didn't, but my battery was fairly flat.