If anyone would know the basics of CVT -_- CVT transimssion have very poor efficiency at low RPM’s, so for esk8 it’s useless. You should achive higher top speed but when it comes to launch and hills it would be quiet poor
How much higher RPM would that be?
isnt 4000-8000 rpm high enough? Most petrol engines mostly work in 2-4 range anyway, I think
Probably you don’t know but cars CVT are more advanced they’ve got additional electrohydraulic system which allows them to set proper gear even if they don’t have such high rpms. This also would be hard to fit (for sure new design of trucks). You need to design CVT specially for the engine(torque) which is another problem. Another thing is that you will have to use high rpms more often and this will probably lower lifecycle of your motor but i’m not sure.
Sorry for me English.
Your english is quite okay! I can understand everything!
Thanks for educating us, as it turns out you are more advanced in this fields than the rest of us (at least for the ones joining this discussion…)
Too bad that they are not effective in low rpm range… I assume a 2 different motor or 2 different gearing system would work better then!
Yep, and 2 gear ratio system should be quiet easy to apply in esk8 as there are similar rc transmissions.
With chain drive it should be easy ass hell ( similar to bike) and anybody can do it diy.
why do you say they’re inefficient at low speed? if a simple cvt is set up right it could have an appropriate gear for low speed. You could decide the gear ratio.
First of all there are no gears in CVT, the ratio is simply changed depends on rpm’s. If you would look at specs of cars you can easly see that always same model with CVT have lower torque than manual one. You say about appropriate setup, indeed this can be achived but than you have to build CVT considering engine and wheels. I don’t think that we can find manfacturer which will supply us proper belts and the ones that we are able to get will fail quiet often. Imagine belt at 3000 rpm hitting parts of your CVT, in most of cases it will result in buying new gearbox. Another thing are trucks we need to redesign them to get a place for CVT pulley. There are a lot of pros when it comes to CVT, smoothnes of ride, battery saving ( they will use less power than your normal setup). But there are also cons as far as i understand the way how CVT works we’ve got huge problem when it comes to brakes, probably you need to use external brakes, no regenerative breaking and maintanance cost.
And yes they are less efficient in power delivery just by design when you compare them to manual.
when you say “manual” I guess you mean stick. tell me if i’m wrong but on a car to achieve the most torque you want to be a gear that allows you to be in a really high rpm. Maybe the cvt for the car you talk of is designed in such a way as to have less torque but its not inherent in a manual vs cvt as you could make the cvt spindle thinner or larger or whatever to achieve a better “gear ratio”.
no brakes is the real deal killer for me.
i read its less efficient but havent gotten to why. dont understand why it would be
http://ecomodder.com/forum/showthread.php/transmission-efficiencies-mt-auto-cvt-27432.html
getting to the bottom of it
in all the efficiency comparisons I come across between manual and cvt the manual is using cogs which are more efficient so it’s not a fair comparison as we’d be using a belt in both situations.
Yep i mean stick (i’m from Poland and in Europe you call it Manual). It work same in CVT, Stick and Automatic to get highest torque you use the gear which has the highest ratio ( drive wheel is biggest). The effectivness difference comes from design stick and automatic transmissions use wheels with teeths so each teeth transfer the torque but when we look at design of CVT it uses friction to transfer torque so you need to loose some of torque.
And if somone think that we can apply teeths on CVT pulley, the belt will wearout quiet faster as you will push it only on sides of belts. There are soultions for cars which use chain instead of belt but our problem is to get such small chain designed and manufactured for us.
since we’d be using a belt in either set-up a cvt would allow the motor to run in it’s most efficient rpm. at slow speeds it seems to run better on efficiency than a car from what I read as a manual doesnt drop down gearing automatically so you end up stuck in a way in an inefficient ratio. (what they say but i dont understand why as it’s manual and you could plan ahead and drop down a gear). the big loss with the cvt seems to be the belt…but we’re doing that anyway, well some of us are.
You are right but we use belt with teeths which work with teeth pulley since that it’s almost same as using gears, cvt pulley doesn’t have teeths it’s all about friction. I’m using stick daily, you can plan to shift a gear just by hearing how your engine is working. Basicly when you hear that rpms are going lower even if you push throttle than you shift to lower gear ( higher gear ratio) and get additional torque. It doesn’t run better on efficiency it just feel smoother beacause you don’t have 1,2,3,4,5,6 gear just one which is automatically adjustable till you reach lowest ratio ( like 6th gear in stick).
This thing looks rather small… can someone comment on the video?>
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I watched it. Goes from 0:1 to 1:1. That seems good for a board but it’s not automatic and u need to physically adjust the lever. And there’s also an over torque safety so if u are in too high a gear, trying to go fast up a steep hill, it won’t do it to protect itself from breaking , and u have to adjust the lever.
So no brakes if u use it, and u need to use another controller other than a simple transmitter for the esc as it’s not automatic like a cvt, and the over-torque safety would likely kick in unwanted.
a cvt would be better on a board I think
Ok thanks, for the review 
could not make all the details from the video myself.
Though, really liked the small form factor, too bad the ratio is so little and that there are some other ‘‘problems’’ / ‘‘stepping stones’’ in this one.
small form factor? this is not the motor but just the “gearbox”. Where would this thing fit on a board in addition to the motor?
ah, well im looking more into mountainboards section,… so longboards are not my primary concern 
sorry for that.
There are a few areas, where pehaps, by not stepping the voltage way much higher, a somewhat ‘‘low-cost’’ gearbox would justify the cost/extra weight… For example, a high ratio gearing for pure off roading - snow riding etc… then, a lower gear ratio for just reaching maximum speed…
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Of course, you can always just switch the pulley on the field… but that’s an extra effort
The gear ratio I think is the good part about it. Confusing with 0:1 to 1:1 but it seems to be effectively an infinitely large wheel pulley , slow, all the way down to a 1:1 which would be effectively the same rpm as the motor and fast
What about something like this: http://www.bigtoysusa.com/evo2speedgearbox.aspx
Why make complications though and lose ur nice smooth brakes.
Especially with an electric motor whatever you’re after; more torque or greater speed, can be had with a simple single gear ratio. The losses of ading extra gearing would very likely be greater than if u just ran a large gear ratio, 3:1 or 4:1 maybe, for the torque u want and a used a really high voltage to get the speed. To get a tiny bit better efficiency u could reduce the voltage but not worth it.
Cool clear gearbox though. if u want to just do it for the fun of it that’s another story
With CVT you will loose your smooth brakes but with geared gearbox you won’t.
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