How Fast is 2000 W?

[eSurfer]

Just for fun, I've been thinking about converting my old Intense Tracer into an eBike. Was thinking about putting a 48V 1000W hub motor on the back wheel and another similar motor on the front. So the result would be 2000W, right? I would use it mostly on the street. I know there are a lot of factors involved and nobody can say for sure, but how fast do you think it would go? 40mph? More, less? How technically difficult is it to run two motors?

 

[t_tberg]

You'd be limited by the speed of your faster motor. Two hub motors will get you to your top speed quicker than one but you would still have the same top speed. Two hub motors would climb hills better than one but I would personally use a single hub and run 2kW through it. I'm using 15s, sometimes 20s at 35amps and am very pleased. At 15s (55.5v) I get about 35mph and 20s (74v) tops out at 40 mph on flat ground (fully charged 62v and 84v respectively).

 

[2old]

My 1000w rear hub was still pulling, but topping out @ 32 mph (bike plus rider 240#, no wind, flat road, 52V, 10 a/h battery, 30 amp controller); think you'll be around 30 mph @48V.

 

[dogman dan]

Yes, because both motors will have less load, perhaps more than 30 mph, but not 40.

The cheap and dirty way to get 40 mph, is the same kit, replace the controller with a 72v 40 amps one, and 72v battery able to handle 40 amps continuous.

But it's pushing the motor very hard, 3000w, so best to keep the high speed runs relatively short. Max speed for more than 10 miles definitely risks overheating that size motor.

Best plan is a motor with wider magnets, 35 mm wide or larger. Then they can take up to 5000w. Then 3000w continuous is not much of a problem, unless you weigh 350 pounds.

If you just want to perk up the torque, but not increase speed all that much, just run the cheap motor kit on a 48v 40 amps controller, 2000w. 30 mph is borderline legal. Is legal in my state, in other states, illegal but not so blatant cops really take notice. 40 mph, that's just flat out riding an uninsured, unregistered home made motorcycle. Bad idea, unless you really never let the tiger out of the cage.

48v 40 amps is a reasonable compromise, between what's legal, and what's a cop magnet.

 

[eSurfer]

Tberg and 2old, thanks so much for that info, helps a lot. Dogman, you just talked me out of it, which is probably a good thing. Thanks. Where do I go o find out what's legal in California?

 

[skeetab5780]

2000w is equivalent to the speed of two really big horses

 

[wineboyrider]

One reason I like my lyen mini monster controller is because I can run at variable voltage ranges. At 12s 25 amps it is a modest commuter controller,, but if I split my pack which happens to be 2 `12s lipo packs is now a 2500 w controller! I use 24s with a 3 speed switch to limit the current and at the flip of a switch I can go into boost mode for a while. You can also do this with a bigger 40 amp controller and lower voltages. I prefer the smaller controller as that is the normal speeds I run....

 

[t_tberg]

There's a thread about legality around here. After a year of riding through the city of Pittsburgh at 1 or 2kW (sometimes 3kW) I haven't gotten in any trouble regarding power levels. I have gotten two tickets for "rol[ing] though traffic control device indicating steady red", complete BS; I stopped next to a cop and started to roll through when the pedestrian walk sign turned on (theres about a one second delay between the stop light and ped signal in the city). Sorry for the rant.

Dogman knows whats up, don't ride like a jackass and you most likely won't be bothered.

https://en.wikipedia.org/wiki/Electric_bicycle_laws#California

looks like CA is limited to 750W and 20mph, so I'd say 1500W and 30mph should let you slide under the radar

 

[2old]

t_ has the answer; 28 mph is legal in CA and you don't need insurance (think it must be PAS at that speed, otherwise 20 mph max with throttle); also 750w max, but I don't know how they'll determine that except by what's indicated on the motor, if anything. I haven't had a problem but always pedal when riding even if it's only "ghost". Top speed so far is 32 mph, but I'm not blatant about it. Look at Assembly Bill 1096 (AB-1096) for complete, if ambiguous, definition.

 

[eSurfer]

There's a thread about legality around here. After a year of riding through the city of Pittsburgh at 1 or 2kW (sometimes 3kW) I haven't gotten in any trouble regarding power levels. I have gotten two tickets for "rol[ing] though traffic control device indicating steady red", complete BS; I stopped next to a cop and started to roll through when the pedestrian walk sign turned on (theres about a one second delay between the stop light and ped signal in the city). Sorry for the rant.

Dogman knows whats up, don't ride like a jackass and you most likely won't be bothered.

https://en.wikipedia.org/wiki/Electric_bicycle_laws#California

looks like CA is limited to 750W and 20mph, so I'd say 1500W and 30mph should let you slide under the radar

Thanks T_, That link was exactly what I was looking for.

 

[eSurfer]

t_ has the answer; 28 mph is legal in CA and you don't need insurance (think it must be PAS at that speed, otherwise 20 mph max with throttle); also 750w max, but I don't know how they'll determine that except by what's indicated on the motor, if anything. I haven't had a problem but always pedal when riding even if it's only "ghost". Top speed so far is 32 mph, but I'm not blatant about it. Look at Assembly Bill 1096 (AB-1096) for complete, if ambiguous, definition.

Thanks. Yes, it's very interesting. I have begun ghost pedaling as I go and nobody has since noticed me or hassled me on the SART trail.

 

[wineboyrider]

Dogmans advice is sound. Ride like a bicycle where bicycle trails and pedestrians are and you should be fine. Ride like a motorcycle 30 + mph where pedestrians and pedal bikes are and you might find yourself in trouble. Ride 30 mph on the side of the highway like I do and still get passed by automobiles and nobody cares.

 

[dogman dan]

FWIW, just about all 1000w 48v motor kits hit the California maximum of 28 mph, some do closer to 30 mph if the motor wind is faster.

I don't get the PAS thing on the new CA law. When looking it up, be sure you have a fresh page, the law changed last winter, but links to the old one will be on the net for eternity.

Build for about 30 mph, and I seriously doubt anybody will care if you have the PAS or not. Just clown pedal when you see a cop. 8)

If you go 2000w and 48v, no cop is going to really know, still about 30 mph top speed, you just get to that speed twice as fast.

All you really need is a battery that can hack it, and a new controller IMO.

 

[Doctorbass]

Ah haa.. what a good question 8)

How Fast is 2000 W?

Here is my answer :

Fast enough for you the first day...:

... and not enough the next days

Then you need MORE

That's the eternal ebike story

Doc

 

[eSurfer]

Ah haa.. what a good question 8)

How Fast is 2000 W?

Here is my answer :

Fast enough for you the first day...:

... and not enough the next days

Then you need MORE

That's the eternal ebike story

Doc

Reminds me of Rockefeller's answer when someone asked how much money a person needs to be happy, and he replied "just a little more."