Search found 2728 matches

by Sunder
Apr 18 2019 1:47am
Forum: E-Bike General Discussion
Topic: High Voltage on DC motors
Replies: 6
Views: 141

Re: High Voltage on DC motors

So it isn’t simple as voltage decreases heat..... Only for the components that are straight resistors. Something like a BBSHD, unless you're towing a lot of weight, it's almost impossible to be in so far wrong a gear, that you damage anything. It can be pretty inefficient if you're in the wrong gea...
by Sunder
Apr 17 2019 11:21pm
Forum: E-Bike General Discussion
Topic: new eZip motor
Replies: 5399
Views: 367673

Re: new eZip motor

That's really encouraging that you're now building solid 30mph bikes. Good on you. Now if you could just monetise that some how - find customers who aren't alcoholics and can pay ;) That'd solve a lot of issues for you. Have you put out feelers on Craigslist? See if you get any interest at any price...
by Sunder
Apr 17 2019 10:53pm
Forum: E-Bike General Discussion
Topic: High Voltage on DC motors
Replies: 6
Views: 141

Re: High Voltage on DC motors

I have a “working understanding” of ohms law..... But don’t have a good grasp on this: If I “lug” a motor, ie leaving my ebike in a high gear and heading up a hill, is it more likely to burn up with a higher voltage. My thoughts are that low voltage would cause higher amps, amps means heat..... so ...
by Sunder
Apr 14 2019 9:55pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: DP-Ninja 8000W 72V 100MPH
Replies: 19
Views: 591

Re: DP-Ninja 8000W 72V 100MPH

Soooo.... yeah, maybe good to check before accusing a whole country :lol: I was referring to the gullible buyers, not to an entire nation. I spend >$10,000 a year on Chinese made products, mostly through Aliexpress, and I have no issues with the vast majority of sellers. However, I do check specifi...
by Sunder
Apr 13 2019 5:11pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: DP-Ninja 8000W 72V 100MPH
Replies: 19
Views: 591

Re: DP-Ninja 8000W 72V 100MPH

So after reading all this, it seems to be *possible* this is a legit bike, but none of you have heard of anyone that bought one from this site without any issues? It's too bad there isn't an easier way to confirm if something like this is bullshit. :cry: You can try a buyers agent in China? Not che...
by Sunder
Apr 13 2019 2:45am
Forum: E-Scooter and Motorcycle General Discussion
Topic: DP-Ninja 8000W 72V 100MPH
Replies: 19
Views: 591

Re: DP-Ninja 8000W 72V 100MPH

When i see false claims from vendors, i tend to step away. It is a sign of more bullshit to come as an owner. What else were they not being honest about? Something the Chinese don't yet understand about (web-savvy) American buyers. They assume "there is a sucker born every minute and two to take th...
by Sunder
Apr 12 2019 3:03am
Forum: E-Scooter and Motorcycle General Discussion
Topic: DP-Ninja 8000W 72V 100MPH
Replies: 19
Views: 591

Re: DP-Ninja 8000W 72V 100MPH

You're the first person to tell me I haven't under spec'd my build. I hope you're right.

I'm not expecting a Hayabusa out of this, but I wanted something closer to a 600cc performance, (0-100 at least) than a 250cc.
by Sunder
Apr 11 2019 9:48pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: DP-Ninja 8000W 72V 100MPH
Replies: 19
Views: 591

Re: DP-Ninja 8000W 72V 100MPH

My motorbike has a 3000W rated motor and is happy to reach 120km/h (75mph) That being said, the actual power drawn from the battery at this speed (according to my smart BMS) is around 8KW. No problem at all, it works perfectly fine. If this bike has a 8000W rated motor, I'm 100% sure it can reach 1...
by Sunder
Apr 11 2019 7:17pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: DP-Ninja 8000W 72V 100MPH
Replies: 19
Views: 591

Re: DP-Ninja 8000W 72V 100MPH

I'm trying to build one with slightly higher performance than that, using the same frame.

From the feedback I've been given, there is no way those performance specs are real.

From owning a Vectrix, I do know cruising about 60mph on the flat takes about 8-9kw,
by Sunder
Apr 10 2019 3:56pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: Knight Electric Motorcycle 5000w
Replies: 75
Views: 3423

Re: Knight Electric Motorcycle 5000w

That's a great outcome.

Hopefully its Paypal taking its anti fraud responsibilities more seriously.
by Sunder
Apr 10 2019 2:18am
Forum: E-Bike General Discussion
Topic: 21kw+ QS273 won't outrun a 250cc?
Replies: 38
Views: 1143

Re: 21kw+ QS273 won't outrun a 250cc?

I think right now, the cost to replace all the bmses, chargers and controllers, and have the wheel rewound is a bit high, when I don't even know what the real world performance is. The good thing is that once it is registered as a road worthy electric motorcycle, I can make modifications to it withi...
by Sunder
Apr 08 2019 7:31pm
Forum: E-Bike General Discussion
Topic: 38mph on 250w motor 48V?
Replies: 16
Views: 512

Re: 38mph on 250w motor 48V?

Anything is possible with the magic of the camera, motor trickery like ATF fluid, steel gears, perhaps a downhill run and start camera action on the flats. By the way, OP posted this in another thread: Got the same bike put a 48v 10ah battery n 48v 30amp controller on it and got 38mph out of it on ...
by Sunder
Apr 08 2019 7:24pm
Forum: E-Bike General Discussion
Topic: 38mph on 250w motor 48V?
Replies: 16
Views: 512

Re: 38mph on 250w motor 48V?

Anything is possible with the magic of the camera, motor trickery like ATF fluid, steel gears, perhaps a downhill run and start camera action on the flats. Well if you want to deceive someone, it's even easier than that: 1. Enter the wrong tyre circumference so the speedo shows twice the real speed...
by Sunder
Apr 08 2019 7:10pm
Forum: E-Bike General Discussion
Topic: 38mph on 250w motor 48V?
Replies: 16
Views: 512

Re: 38mph on 250w motor 48V?

I will be posting a video when the weather is better just too prove it really does 38mph and 25mph up a steep hill it only done this when I added one steel plantery gear as the plastic ones are no good Oh. I get what you mean now. In that case yes. I overrated a 250W motor to 1200W, and was hitting...
by Sunder
Apr 08 2019 6:56pm
Forum: E-Bike General Discussion
Topic: 38mph on 250w motor 48V?
Replies: 16
Views: 512

Re: 38mph on 250w motor 48V?

Note that the headwind negative 25 kph / mph Also note why the O.P. mention 250W, must be another UK'er or other European, since Brexit is not doing much. Just grab the leafbike 1500W in the rear wheel flavor and dont go around pissing people off on the pathways. Well OP didn't put any other restri...
by Sunder
Apr 08 2019 6:21pm
Forum: E-Bike General Discussion
Topic: 38mph on 250w motor 48V?
Replies: 16
Views: 512

Re: 38mph on 250w motor 48V?

I have. This is how I did it:
Fast bike.png
Fast bike.png (43.8 KiB) Viewed 434 times
by Sunder
Apr 08 2019 3:57pm
Forum: E-Bike General Discussion
Topic: 21kw+ QS273 won't outrun a 250cc?
Replies: 38
Views: 1143

Re: 21kw+ QS273 won't outrun a 250cc?

Well, lets get it working first and improve it from there.

Right now, its just lines on a graph, and an expectation that this bike will be underwhelming.

Better to be pleasantly surprised if I am wrong, than frustrated and trying to find a "fault" that doesn't exist if I have just under speced.
by Sunder
Apr 08 2019 1:29am
Forum: E-Bike General Discussion
Topic: new eZip motor
Replies: 5399
Views: 367673

Re: new eZip motor

Haven't those been around for a while? Thought I saw the ride on suit case a couple years ago.

How are you going? Found accommodation yet?

I've started the electric motorcycle project, but won't have a lot of time for it for the next 3 months.
by Sunder
Apr 08 2019 1:02am
Forum: E-Bike General Discussion
Topic: 21kw+ QS273 won't outrun a 250cc?
Replies: 38
Views: 1143

Re: 21kw+ QS273 won't outrun a 250cc?

I'm using the biggest 144v Kelly there is, and that's really capped out at around 30kw battery power. :(
by Sunder
Apr 07 2019 7:21pm
Forum: E-Bike General Discussion
Topic: 21kw+ QS273 won't outrun a 250cc?
Replies: 38
Views: 1143

Re: 21kw+ QS273 won't outrun a 250cc?

What controllers are people using to get that kind of power?
by Sunder
Apr 07 2019 2:34am
Forum: E-Bike General Discussion
Topic: Hello from the UK - unusual project on the go.
Replies: 9
Views: 321

Re: Hello from the UK - unusual project on the go.

I did a short contract for a medical supplies manufacturer. The whole deal is a scam at our expense, but here's how it works: US manufacturer makes some nice gear. They get it certified as medical/disability support equipment, which raises the price substantially. AU importer discovers it during a j...
by Sunder
Apr 05 2019 2:38am
Forum: E-Bike General Discussion
Topic: 21kw+ QS273 won't outrun a 250cc?
Replies: 38
Views: 1143

Re: 21kw+ QS273 won't outrun a 250cc?

Yeah, not going mid-drive. One of the main reasons for going electric is simplicity. I don't want to have to worry about chains or belts, etc. Simple is only simple until you spin an axle by stuffing kNm through a couple cm^2 worth of axle cross-section. Torque is torque regardless of what the sour...
by Sunder
Apr 05 2019 2:36am
Forum: E-Bike General Discussion
Topic: 21kw+ QS273 won't outrun a 250cc?
Replies: 38
Views: 1143

Re: 21kw+ QS273 won't outrun a 250cc?

In my experience so far, the main thing that 2WD does is significantly increase my acceleration on my heavy ebike and etrike (say, taking a 0-20MPH time of 7-8 seconds down to 4-5 seconds or less). If there is enough weight, sure. But for lighter, fast bikes, accelerating hard would take even more ...
by Sunder
Apr 05 2019 12:38am
Forum: E-Bike General Discussion
Topic: 21kw+ QS273 won't outrun a 250cc?
Replies: 38
Views: 1143

Re: 21kw+ QS273 won't outrun a 250cc?

markz wrote:
Apr 04 2019 10:56pm
any thoughts on 2wd ?
Yeah. Not worth it. It only adds a small amount of power but will really unbalance handling.
by Sunder
Apr 04 2019 9:10pm
Forum: E-Bike General Discussion
Topic: 21kw+ QS273 won't outrun a 250cc?
Replies: 38
Views: 1143

Re: 21kw+ QS273 won't outrun a 250cc?

If you wanted a Kelly to not shoot fire, derating its shunts would get you further than turning up a device thats already ran way beyond it's ability to survive long. Also, 273*50mm is bicycle size (i run one on my mt bike). You want 273*70 or 273*80mm minimum for a motorcycle. This is starting to ...