bike gears on electric go kart

[alteran]

yea seants i wana build and desing a all teran go kart that enectric i thot that i culd add gears for speed and wen i need to climb hils and the speed culd help it i want the RPM for ataching a altornator on the cart so im wondering if is posibal and if is worth it ?? and is yes do i build a gear system like a bike but tufer cuss my kart suld wight at 300/400 pounds

 

[fowler]

Please keep this to one thread

Also I understand if English isn't your first language but please turn spell check on
It is a bit of a puzzle to read

 

[alteran]

kk il tri

 

[B man]

kk il tri

The funny part is youd fit right in with the teens in America they all type that way.

 

[alteran]

im french that y my english is a bit bad

 

[Jake.B]

Its hard to create somthing with gears, a transmissioned engine would be best

 

[landuse]

im french that y my english is a bit bad

Then you are excused.

 

[alteran]

Then you are excused.

lol but il tri and do my best for you guys.

and a transmissioned engine is there sume that electric cuss i want gears to help speed it up and gears to give it more power for wen i climb hils and gears to help the power from draning fast

 

[fowler]

Electric cars don't have gears

An electric motor doesn't have a power curve like an internal combustion engine
The power is the same at 1 rmp as at 200 rmp

Electric cars don't have transmissions because they add friction to the drive train

In other words u will use more power than u save

 

[alteran]

well wat about the gears for the engen to the axel i will have a 3 way point so do i go smal to big and smal to big to turn the axel ?

 

[fowler]

u mean u will have a jack shaft
drive from engine to small axle wth two sprokets then finally to the wheels

u need to find the specs of whatever motor u get so the power and the rmp it can achieve

then u need to work out what tyres u are going to useing

from there we can calculate the gear ratios


useing gears like a bike doesnt work too well
a bike chain is too weak and the chain u are going to use wont have enough flex in it

 

[alteran]

kk wen i find out all the dimentions and the engien and all il re poast in this to find that out and yes im talking about a jack shaft idea. thanks =) now i can tri and find that out =)

 

[jman231994]

Actually fowler, if he is using a small electric motor, say sub 3kW, then multiple gears would definitely be helpful. For instance, the electric bike me and my friends built last year for a comp would have been useless without gears, the bike and rider weighed about 90kg all up and was being powered by a 500w motor. Thats less than 1Hp, which even with a flat torque curve is low. Takeoffs werent quick, hill climbing was a chore and in the end the weight killed us.

However, without the gears we would have gone nowhere. The hills would have been impossible and the acceleration would have been utterly hopeless.

Also, we managed to run for just shy of 2 hours averaging around 30kph on a hilly track, on bike chain. Whilst I agree it isnt strong, it is quite suitable in low rpm situations for shortish periods of time

http://www.flickr.com/photos/billcollison/6375537995/

 

[fowler]

Ha that's wicked
We were only getting 1 hour out of our electric vehicle with a hub motor

There is a fair bit of weight differance between a bicycle and an off road kart

 

[jman231994]

Yea true. Although if he built it right he could get it close to 100kg with him in it, would be challenging though. Yea, we were running 40Ah batteries and 24v, they were huge and promising, but 36v and 18Ah turned out giving similar results with much less weight, that let them get up hills better resulting in faster times I regret choosing those godly batteries haha