Trying to achieve 120km/h ebike

[t3krider]

Hello, my previous ebike achieved only 70km/h top speed which was fast but not quite fast enough

I know it sounds crazy but I have my reasons.

I've been trying to figure out the best setup for this, I'm thinking dual motor. But I'm not sure what wattage/voltage per motor would work for this setup.

My previous bike achieved it on 1000w motor kit from AliExpress and if possible I'd love to make it another cheap fast machine.

I also am not sure whether it should be AC or DC, Brushed or Brushless.

And I'm not sure of any manufacturers that make a motor capable of such RPM. Has anyone achieved this before?

 

[JackFlorey]

I've been trying to figure out the best setup for this, I'm thinking dual motor.

Single motor, motorcycle chain drive. You should be able to do the reduction in one stage (i.e. with the chain alone.) Start with an old motorcycle frame (lighter the better) and go with something like this for a motor: (this one is BLDC)

https://www.amazon.com/Motor-Controller-Electric-Motorbike-Cnversion/dp/B075K7PQX7

Batteries can be anything but you'll want to go as high a voltage as possible to keep wiring gauges and controllers reasonable. 96V would probably work well.

 

[MadRhino]

‘’ Cheap fast machine’’

That is suicidal. The faster you ride, the better you need a frame, brakes, wheels...

As for the target speed, it is easy to do with one hub motor, only a bigger one than yours.

 

[Eastwood]

What kind of bike frame? wheels, brakes?
You can definitely achieve that speed with one motor but I think there’s more questions that need to be asked. Have you considered how long it takes to stop going 75 mph with bicycle brakes? You can end up in a bad situation really quick going that fast and not being able to stop.

 

[markz]

I will be waiting to hear Chalo's response :lol:

edit - Well Chalo did respond, pretty tame
I thought he'd go for it :lol:

 

[A-DamW]

I will be waiting to hear Chalo's response :lol:

:thumb:

 

[Chalo]

I know it sounds crazy but I have my reasons.

Yeah, no.

Here's how you do it.
https://www.zeromotorcycles.com/en-ca/model/zero-srs

Doing it with a bicycle is like trying to go 50mph on roller skates. Yeah... but no. Trying to get adults to agree with you about it is dumb, so don't bother.

 

[Eastwood]

https://www.zeromotorcycles.com/en-ca/model/zero-srs

Beautiful looking bike!

 

[Eastwood]

Doing it with a bicycle is like trying to go 50mph on roller skates.

Yeah for sure! For me anything over 40 mph starts to feel sketchy on an E bike. Also without an E break its super dangerous to trust Bicycle brakes at higher speeds.

 

[DogDipstick]

Just buy a particularly high voltage ( 144v) and high power ( 10kW + ) controller.

Problem solved. 120km/h zing!

 

[E-HP]

I also am not sure whether it should be AC or DC, Brushed or Brushless.

What's your budget?

 

[MadRhino]

I prefer keeping the voltage low. 24s is more than enough. Fast winding 30+ lbs DD hub, high C-rate batteries and 250 A controller. Many bikes on ES are doing that speed. It is simple to repeat after others had done it.

Those who did it on cheap bikes seem to have disappeared.

 

[DogDipstick]

I prefer keeping the voltage low. 24s is more than enough. Fast winding 30+ lbs DD hub, high C-rate batteries and 250 A controller. Many bikes on ES are doing that speed. It is simple to repeat after others had done it.

Those who did it on cheap bikes seem to have disappeared.

I am currently torn between a 14s or 16s mid drive bike with 100A design current,:... or a 24s hub bike with a 50A- 60A current continuous goal. Both to hopefully breach 60mph. I can hold alot more aH in the 14s. Just bought the cheapest triple tree Marzocchi ( my first real cartridge Marzo fork!) I could find... An 888 RV. Going on a stripped ebay old frame.
Goal is 60 mph not 75.

 

[MadRhino]

Old frames are not a problem, as long as it is stiff and robust enough to handle that speed. A very good fast ebike can be built with used components. One just need to know how to choose, tune and maintain them in perfect working condition. My most reliable fork is a 2002 Monster T, modified and tuned better than most motorcycle forks riding the streets around.

 

[Chalo]

My most reliable fork is a 2002 Monster T, modified and tuned better than most motorcycle forks riding the streets around.

That's a 13 pound fork, and the opposite of a normal bicycle component. Also it hasn't been made for a long time.

 

[MadRhino]

My most reliable fork is a 2002 Monster T, modified and tuned better than most motorcycle forks riding the streets around.

That's a 13 pound fork, and the opposite of a normal bicycle component. Also it hasn't been made for a long time.

Upgrade and service parts are still available for this fork, and it is simple to mod and work on. Mine is 10 lbs 3 oz today.

We don’t build fast ebikes with ´normal bicycle components, nor frames’. It would be stupid to ride 75 mph on ´mister anybody’s bicycle’. Big stiff frames, top quality suspension and brake components are a must. They can be old, most of the time they are, but they need to be perfect, sometimes mod better than new.

We are conscious that we build and ride ULM (Ultra Light Motorcycles) with full bicycle components and functions. It does require very careful selection, upgrades and maintenance to make them good rides. They are expansive even when built from 20 years old parts, sometimes more than motorcycles of similar performance. Always more if we count our time. I spend an average of 8 K$ to build a bike, all parts included but my time, and another 1.5 K$ a year to maintain it. Most of this money is spent saving weight while meeting performance, resistance and geometry requirements.

ULM ebikes are better than motorcycles in the city, because they handle in the trafic according to their lighter weight, and benefit of bicycle privileges. They are both, motorcycle and bicycle, giving us double the options of course selections to our best advantage. I can cross the parks and the mountain, park on the sidewalk, ride the shoulder to be the first on trafic lights... Nothing beats a fast ebike to commute in a crowded city. ULM is the future, with ULtra light cars and compact transportation in general. We can’t stop population growth, but we can limit their usage of space in the city infrastructures, reduce the mass of their consuming, ease the inconveniences of city commuting...

 

[markz]

ULM is the future, with ULtra light cars and compact transportation in general. We can’t stop population growth, but we can limit their usage of space in the city infrastructures, reduce the mass of their consuming, ease the inconveniences of city commuting...

Ultra Light Motorcycle is a nice touch, good spin.
It will be a long time before North Americans are down with light vehicles.
Gas prices will dictate it, just like how it is in Europe. Though Europe it has a lot to do with tight and narrow streets but their gas prices are quite high to.
https://www.globalpetrolprices.com/gasoline_prices/Europe/

 

[Chalo]

[ULM ebikes are better than motorcycles in the city, because they handle in the trafic according to their lighter weight, and benefit of bicycle privileges.

Motorcycles, "ultra light" or otherwise, don't have bicycle privileges. They can only trespass on bicycle privileges.

 

[MadRhino]

[ULM ebikes are better than motorcycles in the city, because they handle in the trafic according to their lighter weight, and benefit of bicycle privileges.

Motorcycles, "ultra light" or otherwise, don't have bicycle privileges. They can only trespass on bicycle privileges.

If ULM were a separate class yes, but they are ebikes as long as they can be pedaled. And, here the city and local police had accepted them as such. They prefer seeing ebikes and scooters on the street, thus restrict severely the speed on bike paths, and they are not applying ebike laws on the streets. In short, they favor alternate transportation. Some day they will licence all of them and cash on the habits they have created, but for now we are in a grey zone. When I started, I had predicted we’d have 10 years of freedom. But we are at 13 years already, and still free because you know what, the accidents are still killing cyclists on plain pedal bikes. 2 this week. Dealing with stupid car drivers, is safer when you can compete.