Conclusive proof gearboxes are awesome.

[Green Machine]

I have ridden moto moto's bike and it is awesome. It is balanced and graceful....a work of art really. And it still looks like a bicycle.

It does 65 mph, has full suspension, is jumpable, and weighs around 60 pounds.

What direct drive bike can attain those kind of speeds under 100 pounds and also be totally offroad rideable?

Moto moto's bike uses reliable derailleurs which weigh less than a few pounds. His motor and reduction drive system weighs 8 pounds. He is achieving 65mph on a drive system that weighs 10 pounds. Could he do that with a 10 pound direct drive motor reliably? Which motor?

Sure he could put a 30 pound giant direct drive motor on the bike, but then it doesnt look or ride like a bike anymore at all, even if it achieves the same performance more efficiently and reliably. Aesthetics should be important too.

I have seen Lukes bike up close, and that giant motor is pretty heavy looking. I am guessing but that ebike looks to weigh a couple of hundred pounds. Seeing that gigantic motor in real life...it made a big impression on me. I tried to get it in photo. Its big.

IMO weight and bulk should be considered in an ebike application..more so than in an electric car, a drag racer, a locomotive, or a bulldozer.

Oh and Luke is an amazing writer. Holy shit can that man write.

 

[Miles]

http://saeeng.saejournals.org/content/4/1/1267.abstract

 

[Dauntless]

I have one question for all of you: If it were the same cost / weight / everything, would you rather get a bigger motor and double your power, or add a gearbox a with a 2:1 and a 1:1 gear ratio?
I can see even answering that question is not as easy as it might first appear.
-ryan

Your question is absurd.

If there was a correct answerr, we'd most certainly have heard.

 

[John in CR]

spot on Biff,
no one really knows for sure as yet, especially for smaller (sub 10kw) machines. the huge 100Kw+ induction motor motor standard, and lukes bike etc obviously work very well (and should be) single speed but, i reckon the scale changes things a bit for us, to me its a bit too early in the EV game to make a definite simple call, makes it kinda interesting i reckon. :wink:

The single speed is easier to experience than you think. Everyone gets caught up in power only, but especially with a single speed you have to look at geared to what top speed. 10kw geared to 35mph is pretty beastly, but geared to a top speed of 70mph would suck bad in terms of performance unless you're a flyweight.

This really highlights the problem with a multi-speed. You gear it so low gear is properly geared, but high gear will always suck. There's no way around it. That's why it will always be better to invest the weight in more motor unless the multiple gears are needed for multiple uses, ie you use the bike at high load keeping it in low gear, and normal use in high, not shifting like with an ICE. "Because it sounds cool" just doesn't fly...you don't want your laptop sounding like a mainframe computer room from the 70's do you?

We need to be the leaders in wiping out the misconceptions carried over from the ICE age. The gearbox is a great place to start, because it leads to unnecessarily complex and costly vehicles. Who cares if a gearbox helps an overloaded motor be more efficient? It means the motor wasn't properly sized. Use the right size motor and pick up more performance and efficiency through the entire operating range, not just the bottom end. This is a case where the KISS principle truly applies.

John

 

[Miles]

I'd guess that an electric motorbike is the case that's least likely to benefit from any total weight being diverted into a multispeed gearbox....

What's the Cd and frontal area of a Zero bike with a rider in typical stance?

 

[Miles]

I have one question for all of you: If it were the same cost / weight / everything, would you rather get a bigger motor and double your power, or add a gearbox a with a 2:1 and a 1:1 gear ratio?

I can see even answering that question is not as easy as it might first appear.

-ryan

You've loaded the question by the implication that the gearbox would weigh the same as the motor.

If efficiency is included in 'everything' then I can't see any practical reason for choosing the gearbox. I would choose the bigger motor.

 

[besi]

I can't understand why so many of you are arguing with a bigger motor. It's not about a bigger motor its about a gearbox and the same motor or a different with maybe an other wiring and but the same Poweroutput. And under those cicumstances it's clearly that the motor with gearbox wins. You could get a bigger motor but that would need a bigger battery if you want the same topspeed and range.When your goal is to build a lightweight efficient highperformance and highspeed vehicle, a gearbox and a small motor, always working in the optimal rpm range, is clearly what you want.

 

[gwhy!1]

spot on Biff,
no one really knows for sure as yet, especially for smaller (sub 10kw) machines. the huge 100Kw+ induction motor motor standard, and lukes bike etc obviously work very well (and should be) single speed but, i reckon the scale changes things a bit for us, to me its a bit too early in the EV game to make a definite simple call, makes it kinda interesting i reckon. :wink:

The single speed is easier to experience than you think. Everyone gets caught up in power only, but especially with a single speed you have to look at geared to what top speed. 10kw geared to 35mph is pretty beastly, but geared to a top speed of 70mph would suck bad in terms of performance unless you're a flyweight.

This really highlights the problem with a multi-speed. You gear it so low gear is properly geared, but high gear will always suck. There's no way around it. That's why it will always be better to invest the weight in more motor unless the multiple gears are needed for multiple uses, ie you use the bike at high load keeping it in low gear, and normal use in high, not shifting like with an ICE. "Because it sounds cool" just doesn't fly...you don't want your laptop sounding like a mainframe computer room from the 70's do you?

We need to be the leaders in wiping out the misconceptions carried over from the ICE age. The gearbox is a great place to start, because it leads to unnecessarily complex and costly vehicles. Who cares if a gearbox helps an overloaded motor be more efficient? It means the motor wasn't properly sized. Use the right size motor and pick up more performance and efficiency through the entire operating range, not just the bottom end. This is a case where the KISS principle truly applies.

John

On my little 55kg scooter with only 4kw ( which was more like 3.6kw to be honest 75A limit on 12s lipo) and a cv upto around the 35mph it was pretty beastly, so no need for a 10kw motor here , so just imagin a 10kw motor and a cv you will still get this beastly 0-35mph performance but upto a much higher top speed maybe 70-80mph .

People need to stop thinking about GB's as they exsit for gas bikes and cars , there are better suited GB's for use with electric. The tesla only went for the 2 speed trany just so it will be a selling point in there spec , a much higher top speed. if it was just as simple as fit a monster motor then tesla would have a higher top speed and range than it currently has, same as race bikes the EV race bikes are slower top end than a gas race bike if a EV race bike could be made to go as fast and have a reasonable range the same as a gas bike then there will be no need to have separate classes in races. If a Very small, light weight, Cheap 2 speed tranny can be made ( I think this is more than possible ) then this got to be the way to go to help the EV movement and get gas and EV competing side by side, until battery tec doubles or maybe even tripples ( size, weight and capacity ) then the use of a GB is the way to go . When battery tec gets better then maybe then we can start thinking about just fitting bigger motors and drop the GB.

 

[John in CR]

Green Machine,
I know you haven't missed what people have done with 4-5lb RC motors. Scale them up to a 10lb motor that doesn't exist, at least not for a sane price, and I assure you that as a single speed it would run rings around the bike that impressed you so much. While the motors I use are significantly heavier, they're pushing about double the load and I'm only scratching the surface of their potential performance. Don't let typical hubmotors be the basis of your opinion of single speed, because they aren't good quality motors as evidenced by their low efficiency, and they're improperly geared in bicycle size wheels. A comparison to Luke's motor is just silly, because his motor is overkill for the staggering performance level he demands, which is an order of magnitude higher than the bike you rode.

I'm not knocking the moto moto bike. It sounds like a great ebike. What I'm saying is that a multi-speed gearbox on an electric drive is a bandaid to cover up an underpowered system by giving it sufficient low end torque. The part missing from almost everyone's ride experience is good torque in the mid to high end of the speed range. Until you experience the torque you want at the low end with a single speed capable of higher top speed than you want, it won't click for you. The weight of such a motor is less than you think, and Luke, Arlo1, and I can talk till we're blue in the face, but you won't let go of the transmission idea until you throw your leg over one.

John

 

[John in CR]

spot on Biff,
no one really knows for sure as yet, especially for smaller (sub 10kw) machines. the huge 100Kw+ induction motor motor standard, and lukes bike etc obviously work very well (and should be) single speed but, i reckon the scale changes things a bit for us, to me its a bit too early in the EV game to make a definite simple call, makes it kinda interesting i reckon. :wink:

The single speed is easier to experience than you think. Everyone gets caught up in power only, but especially with a single speed you have to look at geared to what top speed. 10kw geared to 35mph is pretty beastly, but geared to a top speed of 70mph would suck bad in terms of performance unless you're a flyweight.

This really highlights the problem with a multi-speed. You gear it so low gear is properly geared, but high gear will always suck. There's no way around it. That's why it will always be better to invest the weight in more motor unless the multiple gears are needed for multiple uses, ie you use the bike at high load keeping it in low gear, and normal use in high, not shifting like with an ICE. "Because it sounds cool" just doesn't fly...you don't want your laptop sounding like a mainframe computer room from the 70's do you?

We need to be the leaders in wiping out the misconceptions carried over from the ICE age. The gearbox is a great place to start, because it leads to unnecessarily complex and costly vehicles. Who cares if a gearbox helps an overloaded motor be more efficient? It means the motor wasn't properly sized. Use the right size motor and pick up more performance and efficiency through the entire operating range, not just the bottom end. This is a case where the KISS principle truly applies.

John

On my little 55kg scooter with only 4kw ( which was more like 3.6kw to be honest 75A limit on 12s lipo) and a cv upto around the 35mph it was pretty beastly, so no need for a 10kw motor here , so just imagin a 10kw motor and a cv you will still get this beastly 0-35mph performance but upto a much higher top speed maybe 70-80mph .

People need to stop thinking about GB's as they exsit for gas bikes and cars , there are better suited GB's for use with electric. The tesla only went for the 2 speed trany just so it will be a selling point in there spec , a much higher top speed. if it was just as simple as fit a monster motor then tesla would have a higher top speed and range than it currently has, same as race bikes the EV race bikes are slower top end than a gas race bike if a EV race bike could be made to go as fast and have a reasonable range the same as a gas bike then there will be no need to have separate classes in races. If a Very small, light weight, Cheap 2 speed tranny can be made ( I think this is more than possible ) then this got to be the way to go to help the EV movement and get gas and EV competing side by side, until battery tec doubles or maybe even tripples ( size, weight and capacity ) then the use of a GB is the way to go . When battery tec gets better then maybe then we can start thinking about just fitting bigger motors and drop the GB.

Hi speed is all but useless when it takes a week to get there. It's also significantly less efficient too when your ride is too steeply geared, not to mention less safe when acceleration at moderate speeds is greatly compromised.

 

[Arlo1]

I have one question for all of you: If it were the same cost / weight / everything, would you rather get a bigger motor and double your power, or add a gearbox a with a 2:1 and a 1:1 gear ratio?
I can see even answering that question is not as easy as it might first appear.
-ryan

Your question is absurd.

I like how he can strait up ask you a question and everyone argues the question rather then answering.... Yes this is not a real world application but it is a question to make you think then when you stumble onto this in the real world you will understand why.

 

[besi]

Hi speed is all but useless when it takes a week to get there. It's also significantly less efficient too when your ride is too steeply geared, not to mention less safe when acceleration at moderate speeds is greatly compromised.

We are not talking about weeks to get there but a few seconds more. And having the possibility to do that is better than not having the possibility. The second argument that is less efficient is not true. You need the same amount of energy to mantain that speed and if the motor is in his efficient rpm range it's not less efficient. Why should acceleleration be greatly compromised? I think it's the oposite. With a direct drive the acceleration and the top speed is greatly compromised. With a gb you can have the same or better acceleration of an direct drive and a higher top speed because you have gearing and can select the gear in wich you are driving. As an example in the first gear you have a gearing of 1:0,6 and accelerate faster as an direct drive to a given speed. After that speed you can shift to the second with a 1:1 ratio and have nearly the same acceleartion. When now the direct drive tops out you shift into third with a 1:1,2 ration and can have a higher top speed. So 60% of the speed range of the direct drive you have a better accelaration 40% the same accelaration and 20% more top speed assuming that the power of the motor is enough to overcome the windresistance.

 

[h0tr0d]

I have one question for all of you: If it were the same cost / weight / everything, would you rather get a bigger motor and double your power, or add a gearbox a with a 2:1 and a 1:1 gear ratio?

I can see even answering that question is not as easy as it might first appear.

-ryan

You've loaded the question by the implication that the gearbox would weigh the same as the motor.

If efficiency is included in 'everything' then I can't see any practical reason for choosing the gearbox. I would choose the bigger motor.

Agreed. Look at Bearing's graph's
I always try to make things as simple as possible to get my objectives.
The real argument here is your "If it were the same cost / weight / everything". MotoMoto example leads to believe there's a good point in adding gears to a system because of weight, compactness of the system, and perhaps cost and availability of parts.

Here's a total fail when a guy wanted acceleration, top speed and was also "allergic to transmissions".
http://en.wikipedia.org/wiki/Eliica
8 wheels with DD motors!

Most wind turbines aren't direct drive, at the moment. but developers are going that way. I would say "of course they are", its a limited speed application.
They are trading mechanical complexity and problems for electrical complexity and problems.
let's wait and see.

I want to do an electric motocross bike that can win a supercross race. The Zero MX bike claims 54 horsepower at about 4,000 rpm
with no gearbox. Brammo claims 54 horspower at 8,000 rpm with a 6-speed transmission. Decisions, decisions...

Don't know if you read this.
http://www.motorcycle.com/manufacturer/2013-brammo-empulse-r-review-91479.html
Apparently these guys agree with me, gears are better, 6 gears are too many, so I'd say design something with 3 gears...

 

[mr.electric]

A lot of vehicle technology is geared towards what consumers want not what they need. Where is the logic in $2000 for leather seats?
If consumers want transmissions on an Electric Motorcycle give em transmissions. Brammo might have a gear box just to satisfy customers knowing full well it is not really needed.
Which is selling better anyways Zero or Bramo? I bet the sales numbers are more related to marketing than the actual technology.
The best selling vehicle of all time is a crappy 49cc 4stroke honda moped and it's clones. http://en.m.wikipedia.org/wiki/Honda_Super_Cub
Why is a 49cc engine the most widely produced engine in history? Vehicle regulations in various countries make that cheaper to own and operate than larger displacement engines.
What is the ideal electric bike motor transmission set up? Depends on the regulations, consumer demand,marketing. Unless your concept of ideal is something that will never sell and cause the manufacturer to go out of business and cease production and support. Ideal for ebikes will include a transmission in Japan and europe, no transmission in china.

 

[Chalo]

Here's a total fail when a guy wanted acceleration, top speed and was also "allergic to transmissions".
http://en.wikipedia.org/wiki/Eliica
8 wheels with DD motors!

8 wheel drive and a demonstrated 230mph is a fail to you?

[youtube]G2y8Sx4B2Sk[/youtube]

Granted, the Eliica is big and expensive, but it's faster than supercars that cost more, and two and a half feet shorter than the Sedan De Ville my dad had back in the '80s. If that's a fail, then a Bentley is a much worse one.

 

[gwhy!1]

Hi speed is all but useless when it takes a week to get there. It's also significantly less efficient too when your ride is too steeply geared, not to mention less safe when acceleration at moderate speeds is greatly compromised.

as already been said we are not talking a week to get there only a few secs more, the scoot would do 0-30 in around 3 secs ( on 3.6kw ) I guestimate maybe 0-60'ish in around 5secs with a 10kw on tap this is with using a CVT with maybe a top speed of around 70-80mph so to comment on your next bit it will never be to steeply geared and did I already say this was a CVT so its always in the best gear ratio for acceleration at what ever speed you are travelling so no compromise there either .

 

[besi]

Here's a total fail when a guy wanted acceleration, top speed and was also "allergic to transmissions".
http://en.wikipedia.org/wiki/Eliica
8 wheels with DD motors!

8 wheel drive and a demonstrated 230mph is a fail to you?

[youtube]G2y8Sx4B2Sk[/youtube]

Each of the wheels has a 60 kW (80 hp) electric motor, giving a 480 kW (640 hp) eight wheel drive which can tackle all kinds of road surfaces.

There are currently (as of 2005) two versions of the Eliica: a Speed model and an Acceleration model. The Speed model is made to challenge gasoline-based records and has a top speed of 370 km/h (230 mph) with a range of 200 km (120 mi). The Acceleration model is made for the street and has a top speed of 190 km/h (120 mph) with a range of 320 km (200 mi).

Not fail having 480kw and just doing 190km/h that is doable from a 80kw diesel family sedan. hahahaha

 

[John in CR]

Hi speed is all but useless when it takes a week to get there. It's also significantly less efficient too when your ride is too steeply geared, not to mention less safe when acceleration at moderate speeds is greatly compromised.

The second argument that is less efficient is not true. You need the same amount of energy to mantain that speed and if the motor is in his efficient rpm range it's not less efficient.

This is factually incorrect. In high the smaller motor is steeply geared in relation to its power and cannot run at the same efficiency as the larger motor of equal quality. As soon as you shift to high gear performance and efficiency will be less than with the larger motor throughout that high gear range.

It's not like electric traction motors aren't a mature technology in many ways, and they don't use multi-speed trannies. Forget about ICE's and their compromises and go back to the example of a train's motor, no multiple gear ratios, though I understand they do use an electrical shift. It's similar to the series/parallel switch on the windings of my Mini-Monster motors. With mine, unlike with multiple mechanical gears, there's no fall off in the torque when switching to high due to the lower BEMF and copper resistance going from series to parallel. Peak efficiency is actually greatest in high, so there's also no fall off in efficiency either, unlike a mechanical shift.

Let go of the ICE and pedal power thinking. Electric motors are too much better. Also don't let typical hubmotors cloud your judgment about single speeds either, because mid to low 80's peak efficiency that are so thermally limited can't be part of any optimization path other than maybe from an economic standpoint for low power ebikes.

John

 

[John in CR]

Hi speed is all but useless when it takes a week to get there. It's also significantly less efficient too when your ride is too steeply geared, not to mention less safe when acceleration at moderate speeds is greatly compromised.

as already been said we are not talking a week to get there only a few secs more, the scoot would do 0-30 in around 3 secs ( on 3.6kw ) I guestimate maybe 0-60'ish in around 5secs with a 10kw on tap this is with using a CVT with maybe a top speed of around 70-80mph so to comment on your next bit it will never be to steeply geared and did I already say this was a CVT so its always in the best gear ratio for acceleration at what ever speed you are travelling so no compromise there either .

Gwhy,

You're fooling yourself if you think your choice to use a smaller motor doesn't trade acceleration at mid range speeds and up with the CVT helping it match the low end torque of a larger motor. You came to electrics with knowledge and experience with ICE transmissions and CVT's, so of course it will be harder for you to let it go. Like Luke it will probably take riding an extreme performance machine before you see it, a machine that has more torque than you can use at almost any speed, and has a top speed faster than you want to go. I was lucky that my performance needs are much lower, so even with limited skills, tools and experience I was able to DIY mine once I got my hands on the right motors.

FWIW I had a Comet CVT on my very first EV build, and yeah it enabled that lead pig to climb a 25% grade after leaving the driveway, but that's was its only benefit.

 

[besi]

It's not like electric traction motors aren't a mature technology in many ways, and they don't use multi-speed trannies. Forget about ICE's and their compromises and go back to the example of a train's motor, no multiple gear ratios, though I understand they do use an electrical shift. It's similar to the series/parallel switch on the windings of my Mini-Monster motors. With mine, unlike with multiple mechanical gears, there's no fall off in the torque when switching to high due to the lower BEMF and copper resistance going from series to parallel. Peak efficiency is actually greatest in high, so there's also no fall off in efficiency either, unlike a mechanical shift.

That may be a good argument elecrical shifting. But doesn't matter how we need a sort of shifting to get the best of both world accelaration and top speed. John do you have a buildthread i would like to see your Mini-Monster sound intresting to me..

 

[John in CR]

It's not like electric traction motors aren't a mature technology in many ways, and they don't use multi-speed trannies. Forget about ICE's and their compromises and go back to the example of a train's motor, no multiple gear ratios, though I understand they do use an electrical shift. It's similar to the series/parallel switch on the windings of my Mini-Monster motors. With mine, unlike with multiple mechanical gears, there's no fall off in the torque when switching to high due to the lower BEMF and copper resistance going from series to parallel. Peak efficiency is actually greatest in high, so there's also no fall off in efficiency either, unlike a mechanical shift.

That may be a good argument elecrical shifting. But doesn't matter how we need a sort of shifting to get the best of both world accelaration and top speed. John do you have a buildthread i would like to see your Mini-Monster sound intresting to me..

The switching is done via spring loaded contacts inside the motor and a mechanical shifter rod inside a hollow axle. The nature of the shifting mechanism limits it to moderate current use. Bluefang has one that he gutted the shifting and hard wired it to high. He's still working out chain, gearing, CA tuning, and flame flex issues, but he'll have extreme enough power with what ended up an 8-9kg motor that he definitely won't need multi-speed. He too started off thinking multi-gearing would be a plus, but after it ripped his NuVinci apart he realized a fixed single speed will be fine. Even at over 120V the no-load current for that high efficiency hubbie proved to be low, so it will have no problem in ventilated form at 15-20kw or higher peak input as a mid-drive. I wish low cost 200V controllers were available, since the high quality stator lams support much higher rpm. We don't know what saturation is, so we don't know the true limits of the motor.

Here's Bluefang's thread http://endless-sphere.com/forums/viewtopic.php?f=28&t=45165

The factory used it on a low power lead scooter, and the switching of the windings was needed to lower the Kv so the motor wouldn't have heat problems in stop-n-go traffic or going slower up hills. It's the low speed stuff where high Kv hubbies can have heat problems. They love to get up and gallop.

John

 

[gwhy!1]

Hi speed is all but useless when it takes a week to get there. It's also significantly less efficient too when your ride is too steeply geared, not to mention less safe when acceleration at moderate speeds is greatly compromised.

Gwhy,

You're fooling yourself if you think your choice to use a smaller motor doesn't trade acceleration at mid range speeds and up with the CVT helping it match the low end torque of a larger motor. You came to electrics with knowledge and experience with ICE transmissions and CVT's, so of course it will be harder for you to let it go. Like Luke it will probably take riding an extreme performance machine before you see it, a machine that has more torque than you can use at almost any speed, and has a top speed faster than you want to go. I was lucky that my performance needs are much lower, so even with limited skills, tools and experience I was able to DIY mine once I got my hands on the right motors.

FWIW I had a Comet CVT on my very first EV build, and yeah it enabled that lead pig to climb a 25% grade after leaving the driveway, but that's was its only benefit.

You are correct that I did come to the EV world with a pretty good knowlage of ICE CVT , and your statement above proves that you know very little about cvt 's .. How can mid range acceleration be compromised if the CVT will always keep the gear in the optimum ratio. the only thing with using a smaller motor is the top speed will be reduced .

 

[liveforphysics]

I have one question for all of you: If it were the same cost / weight / everything, would you rather get a bigger motor and double your power, or add a gearbox a with a 2:1 and a 1:1 gear ratio?
I can see even answering that question is not as easy as it might first appear.
-ryan

Your question is absurd.

I like the irony of telling him the question is absurd, while typing it in Germany using at least some percentage electrical energy (perhaps very small but still there) that was generated by the man you're rudely critiquing's own wind turbine designs, or that its posting to a sever in Canada also partially being powered by this same mans designs (which you don't typically hear about exploding on fire and crap like the early gearbox wind turbines), to tell this man he doesn't know even what a reasonable question looks like.

Go armchair crew Go!

 

[Toorbough ULL-Zeveigh]

I have one question for all of you: If it were the same cost / weight / everything, would you rather get a bigger motor and double your power, or add a gearbox a with a 2:1 and a 1:1 gear ratio?
I can see even answering that question is not as easy as it might first appear.
-ryan

Your question is absurd.

I like the irony of telling him the question is absurd, while typing it in Germany using at least some percentage electrical energy (perhaps very small but still there) that was generated by the man you're rudely critiquing's own wind turbine designs, or that its posting to a sever in Canada also partially being powered by this same mans designs (which you don't typically hear about exploding on fire and crap like the early gearbox wind turbines), to tell this man he doesn't know even what a reasonable question looks like.

Go armchair crew Go!

ha!, i luv the karma.
since the begining i've banged my head against this wall till my ears bled trying to get the cognocenti to wake up & get it even resorting to using the same vocabulary words like band-aid & crutch.
it only took you only how many years on ES to finally see the light?
now it's your turn, your ears can bleed taking up the torch of 'enlightenment'.
wish you luck but i doubt you'll have any more success at it.

actually it's more like pissing into the wind, you just keep getting blowback, eventually you tire of the salty spray.
John in CR is correct that the only convincer is a visceral one which proved true for you too.
well, that & biff taking you out behind the woodshed for a sound beating upside the head regarding the facts of life.
i can see why some tech is held black, why bother(?), people just can't handle the truth.

 

[besi]

I don't know if this video was previously posted on this thread but something like this could make a gb for ev useless: [youtube]YaIwTTpztaI[/youtube]