Search found 13492 matches

by John in CR
Apr 30 2019 8:49pm
Forum: Motor Technology
Topic: High Voltage versus High Current
Replies: 13
Views: 2248

Re: High Voltage versus High Current

Resistive losses are comparatively small to whatever portion of your energy isn't going toward propulsion. What is the efficiency of the motor, under heavy load? 70%? The other 30% is dissipated as heat regardless of the volt / amp proportion. If your resistive losses are a significant fraction of ...
by John in CR
Apr 30 2019 8:30pm
Forum: Items for Sale - Used
Topic: SOLD - 3kw DD motor on 19" moped rim
Replies: 12
Views: 863

Re: 3kw mxus clone 19" moped - 325$

There's no such thing as a mxus clone. That's like saying I'm selling the generic form of Walmart aspirin. :mrgreen:
by John in CR
Apr 29 2019 5:06pm
Forum: Items for Sale - New
Topic: PV NextGen Controller FOC compact 150v 22kw Max - $499
Replies: 31
Views: 1516

Re: PV NextGen Controller FOC compact 150v 22kw Max - $499

What motors has this been tested on? Any low inductance high Kv hubbies?
by John in CR
Apr 28 2019 2:19am
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: Denzel 72v 4-spd Gearbox Build DB17
Replies: 48
Views: 1857

Re: Denzel 72v 4-spd Gearbox Build DB17

Instead of spacers between the hub and sprocket, I think it would be easier to do it with washers on the axle. Then just dish the wheel some at the end to center the tire after you get proper sprocket alignment. It looks like dishing will be needed anyway. Something I've been wondering about is how ...
by John in CR
Apr 28 2019 1:49am
Forum: Motor Technology
Topic: How many Amps can this 3500W rated QS hub motor actually take? (build planning)
Replies: 20
Views: 543

Re: How many Amps can this 3500W rated QS hub motor actually take? (build planning)

I hope you replaced those original phase wires. That cracked insulation could quickly lead to burning up a controller, and the crack on that blue wire makes all of the original suspect. It's always best to do it all right the first time. There's no better transportation that an absolutely reliable E...
by John in CR
Apr 26 2019 6:47pm
Forum: Motor Technology
Topic: High Voltage versus High Current
Replies: 13
Views: 2248

Re: High Voltage versus High Current

While watts are watts, with a given motor you will absolutely not get the same results with 10V at 120A as you would with 120V at 10A. The voltage and current limits of a motor depend upon it's construction and how it is wound. It is generally best to run a given motor at the highest voltage it was ...
by John in CR
Apr 26 2019 5:48am
Forum: E-Scooter and Motorcycle General Discussion
Topic: Buell Fuell Flow motorcycle
Replies: 18
Views: 668

Re: Buell Fuell Flow motorcycle

100kph is just 62mph. Apparently though you live in Texas you've never been to Houston or Dallas, where you better be able to maintain a higher cruising speed than that if you want to be safe. Going slower than traffic simply isn't the safest way to ride on two wheels.
by John in CR
Apr 24 2019 9:06am
Forum: Motor Technology
Topic: Hubmonster teardown
Replies: 13
Views: 652

Re: Hubmonster teardown

Looks like a really well designed hubmotor! Im impressed! If you hunt around, you'll eventually come across an old scooter with one. That's how I got both of mine. Or you can just buy one from John in CR. However you get one, it's a compelling hub motor. I sent one to LFP a few years ago. He just h...
by John in CR
Apr 23 2019 6:12pm
Forum: Motor Technology
Topic: Hubmonster teardown
Replies: 13
Views: 652

Re: Hubmonster teardown

60mm is the most powerful and fastest with a Kv of just over 18. The lesser version are wound slower (so higher resistance) to offset the lowering of Kv to offset the narrower stator. No need to open...measure phase-to-phase resistance and Kv to know what you have. While 3 jaw pullers make getting t...
by John in CR
Apr 23 2019 2:44am
Forum: Motor Technology
Topic: Hubmonster teardown
Replies: 13
Views: 652

Re: Hubmonster teardown

The only valid reason to pull the stator on one is to do cooling mods on the shell. The important stuff inside was all shared previously. How wide was the stator?...probably the largest if that's for the R Martin, but there were actually 3 different widths offered, and it's impossible to tell by the...
by John in CR
Apr 23 2019 2:23am
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 1307
Views: 58342

Re: la Nina rears her ugly head

Shorts and t-shirt weather every day. Lows 60-65 highs 70-80 depending on cloud cover or sun. Last year was kinda sucky with wetter than normal, but this year is shaping up to be more typical, so if it does rain it's in the afternoon with dry roads by commuting home time. In the tropics in the mount...
by John in CR
Apr 22 2019 5:28pm
Forum: E-Bike Reviews & Testing
Topic: Cycle Analyst V3 preview and first beta release
Replies: 4453
Views: 657464

Re: Cycle Analyst V3 preview and first beta release

If I try the current throttle through the CA, once I get it dialed in is there any risk with a very high power rig? I'd hate to be out riding on wet roads especially and have the throttle suddenly turn into a pass-through throttle mode. I use Zombiess Throttle Tamers now to slow the throttle ramp up...
by John in CR
Apr 20 2019 5:50pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: Buell Fuell Flow motorcycle
Replies: 18
Views: 668

Re: Buell Fuell Flow motorcycle

35kw with a hubbie that has flat smooth side covers will be a fail in real world use. The engineers obviously didn't learn much in their thermodynamics class. That's one thing QS got mostly right with their side covers on the 273 motors, though I would have gone further to increase surface area both...
by John in CR
Apr 20 2019 1:19pm
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: John's HubMonster powered MadAss hits 182kph (113mph)
Replies: 4
Views: 392

Re: John's HubMonster powered MadAss hits 182kph (113mph)

Thanks guys. This is the first build I've spent beautification time on, so it came out passable. Plus I learned more do's and don't, which is what really matters. I have to fab another fiberglass underbelly for rain proofing and she's ready for long-term use. All I need is something more aero, and t...
by John in CR
Apr 19 2019 6:28pm
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: John's HubMonster powered MadAss hits 182kph (113mph)
Replies: 4
Views: 392

John's HubMonster powered MadAss hits 182kph (113mph)

I finally got around to a top speed run with my Sachs MadAss 125cc conversion. Despite the overly heavy parts off of the MadAss, especially the entire front end, that put my total build weight at just over 100kg carrying only a 115V 26ah nominal battery, I was able to hit 182kph (113mph), improving ...
by John in CR
Apr 19 2019 7:45am
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: Denzel 72v 4-spd Gearbox Build DB17
Replies: 48
Views: 1857

Re: Denzel 72v 4-spd Gearbox Build DB17

234W to turn the motor and new gearbox not run in yet at half rpm doesn't seem bad to me at all. It will be interesting to see how the no-load changes as the gearobx gets run in and add the wheel and chain. Personally I'd give it 15-30min of run in each geat at that 36V before full assembly and chan...
by John in CR
Apr 18 2019 11:27pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: Yamaha V Star 1100 Conversion
Replies: 33
Views: 864

Re: Yamaha V Star 1100 Conversion

This went from a cheap build to carry 2 people 200 miles to now a wind generator on the bike to charge the battery while riding, so the thread title should be "The impossible dream that defies the laws of physics".
by John in CR
Apr 18 2019 2:07pm
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: Denzel 72v 4-spd Gearbox Build DB17
Replies: 48
Views: 1857

Re: Denzel 72v 4-spd Gearbox Build DB17

skeetab5780 wrote:
Apr 16 2019 6:32am
draws 6.5amps at 10s full throttle which is pretty high id imagine the motors no load current should be less than half of that without the gearbox
6.5A at 40ish volts...In gear or in neutral?
by John in CR
Apr 18 2019 2:02pm
Forum: Motor Technology
Topic: How many Amps can this 3500W rated QS hub motor actually take? (build planning)
Replies: 20
Views: 543

Re: How many Amps can this 3500W rated QS hub motor actually take? (build planning)

If it only did 70kph at 72, then it's a slower winding, more turns on the teeth, so longer thinner copper, which can't handle current as high as the one I have. You need those measurements and opening the motor won't tell you. Opening would only enable you to measure the stator width to verify it's ...
by John in CR
Apr 17 2019 5:04pm
Forum: Motor Technology
Topic: How many Amps can this 3500W rated QS hub motor actually take? (build planning)
Replies: 20
Views: 543

Re: How many Amps can this 3500W rated QS hub motor actually take? (build planning)

That version was produced with different windings (different Kv), and current handling varies directly with Kv, because resistance of the copper windings varies. Kv (rpm/volt) is a pretty good indicator, but the best method is to measure the phase to phase resistance, so you can computer heat create...
by John in CR
Apr 16 2019 7:06pm
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: Light Electro Bobber (short version)
Replies: 48
Views: 1617

Re: Light Electro Bober (short version)

I've been thinking about your battery layout, and I have some concern regarding the lack of compression applied to the individual cells. Every electric car battery I've disassembled has had compression force on the 2 faces of the cells. It is an important part of the battery structure affecting bot...
by John in CR
Apr 16 2019 12:34pm
Forum: Items for Sale - New
Topic: Hubmonster 94% efficient 7kw NO LONGER FOR SALE
Replies: 454
Views: 64972

Re: Hubmonster 94% efficient 7kw rated $587

$100-200 is more than their cost for the entire ebike hubbie. While you and I believe there is a market for a high priced, high quality, high power ebike hubbie, it's too small a niche due to the oppressive ebike laws in much of the world. In the meantime, suckers will continue to pay high prices fo...
by John in CR
Apr 15 2019 11:12pm
Forum: Items for Sale - New
Topic: Hubmonster 94% efficient 7kw NO LONGER FOR SALE
Replies: 454
Views: 64972

Re: Hubmonster 94% efficient 7kw rated $587

Do you have any web links to the patents for this motor? I'm wondering if it would be possible to build/sell a smaller/lighter/not-nearly-as-powerful motor using the 6 phase design that would use a freehub and 8/9/10sp bicycle cassettes without running afoul of the patents, perhaps something weighi...
by John in CR
Apr 15 2019 2:10pm
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: Light Electro Bobber (short version)
Replies: 48
Views: 1617

Re: Light Electro Bober (short version)

I've been thinking about your battery layout, and I have some concern regarding the lack of compression applied to the individual cells. Every electric car battery I've disassembled has had compression force on the 2 faces of the cells. It is an important part of the battery structure affecting both...
by John in CR
Apr 15 2019 11:22am
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: Denzel 72v 4-spd Gearbox Build DB17
Replies: 48
Views: 1857

Re: Denzel 72v 4-spd Gearbox Build DB17

I look forward to the no-load current number. If there's an easy way to pull the drive gear to get a no-load current number of motor only along with including the gearbox, that would be an awesome comparison that answers questions I've had for many years. Since it apparently has a neutral, no-load c...