Author Topic: EV transmissions  (Read 2417 times)

Richard230

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EV transmissions
« on: February 20, 2015, 06:02:50 PM »
According to a the following statement on page 22 of the March issue of Popular Science, electric vehicles (not necessarily motorcycles) may have a transmission in their future.  Here is the statement:

Single-speed EV transmissions will give way to two-speed units within 5 to 6 years, according to German supplier ZF.  As with gas powered cars, adding more gears to electric motors will make them more efficient, extending their range by up to 20 percent.

Note that ZF makes transmission for many brands of automobiles and has done so for years. I believe that they also make (or used to make) transmissions for some motorcycle brands, such as BMW. 
current bikes: 2018 16.6 kWh Zero S, 2011 Royal Enfield Bullet 500 Classic, 2009 BMW F650GS, 2007 BMW R1200R, 2005 Triumph T-100 Bonneville, 2002 Yamaha FZ1 and a 1978 Honda Kick 'N Go Senior.

RickXB

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Re: EV transmissions
« Reply #1 on: February 20, 2015, 06:48:04 PM »
maybe some peoples will figure out that a transmission is maybe not REQUIRED but not USELESS either ;)

benswing

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EV transmissions
« Reply #2 on: February 20, 2015, 08:26:17 PM »
Tesla tried a 2-speed transmission with their roadster.  It failed and they never looked back.  Now they have the quickest production electric car with the longest range. 

Unsurprising that a transmission company would think they are a good idea putting them where they aren't needed.


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7racer

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EV transmissions
« Reply #3 on: February 22, 2015, 12:54:27 PM »

Tesla tried a 2-speed transmission with their roadster.  It failed and they never looked back.  Now they have the quickest production electric car with the longest range. 

Unsurprising that a transmission company would think they are a good idea putting them where they aren't needed.


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True. I own both a Teslas and the Brammo. I love the simplicity of the Teslas with one gear BUT for performance imthe tesla really needs an extra gear. It is really evident when you watch the drag videos as the Model S blows by everything off the line but runs out of steam and gets reeled in.

About distance, I'm not sure. If a 20% increase in range is possible the. I think they will move rapidly to it.

I am hoping they do it more for performance. Taking the Tesla (roadster) out on the track you can easily see it get winded j. The straights.


MichaelJ

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Re: EV transmissions
« Reply #4 on: February 22, 2015, 02:57:25 PM »
The LITO Sora has a CVT.  A CVT doesn't offer discrete gears, but is not a one-speed, either.  If transmissions don't make sense for a modern EV, then why is LITO Green Motion betting their customers will spend a pretty penny on it?

I have a vehicle with a CD player.  It happens to be an EV: a Nissan LEAF.  It also has Bluetooth and a USB port for supplying the music player with content.  Arguably, the CD player is not needed.  But it's there.  For those who still use physical media, the CD player is useful.

I enjoy my Empulse R, gearbox and all.  The gearbox is useful for on-the-fly adjustments of regenerative braking power on the hills in my area as described by Shinysideup.  The Zero can't do this on the fly, but I'm not going to rain on Zero's parade because of it.  Instead, I'll tease it about its ongoing lack of reliable DC fast charging.  :)


I appreciate having experienced (and continuing to experience) operating an e-motorcycle with a gearbox.  It is not a bad experience, and if transmissions disappear from all EVs in the future, I won't whine about it.
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00049 (AKA SopFu)

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Re: EV transmissions
« Reply #5 on: February 22, 2015, 09:08:03 PM »
It seems to me that transmissions only add a significant benefit when the vehicle is operated near it's maximum potential. Like on a race track (formulaE), or moving heavy loads (electric garbage trucks, dock trucks, etc), or when the powertrain is simply under-powered relative to the expectations of performance (electric kei cars).

As Tesla has shown, with enough power, a transmission is not needed.
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BrammoBrian

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Re: EV transmissions
« Reply #6 on: February 22, 2015, 11:59:22 PM »
I think the question we have to ponder before you answer this question is... "What is ENOUGH performance?".  The Tesla is certainly quick in a sprint from 0-60mph, but it's not going to win a race against a real sportscar around a track or for anything more than a 1/4 mile drag.  This is still more than ENOUGH performance for most people, even though it is possible to have more.  The truth is that IF the Tesla had a transmission, the performance would be even more impressive.  The 0-60 time might not improve much due to adhesion limits of tires, but the top speed could certainly be increased.  So... it's not that the transmission was "useless", just that Tesla determined they could meet the minimum performance expectation for the majority of their customers (ENOUGH) to be happy without including the additional cost. This is smart value engineering and great customer centric design decision making, not ultimately a technical decision of what is “best”.

With motorcycles, I think it is even more subjective.  I have ridden many, many direct drive motorcycles in my career including the Mission R, Vectrix Maxi-Scooter, KTM Freeride, 2014 Zero S, 2011 Zero X, and our own Enertia, Empulse prototype, and Empulse RR race bike.  In some cases, the performance was ENOUGH, and others it was not.

I agree that for the most part - the buying public is leaning towards a compromise of ease of use over outright performance in EV.  I am hopeful that there will still be those among us that continue to push for performance though as we show the way for what is possible.   This is one of the reasons I have built the Empulse HVR (see News thread) to combine a high voltage drivetrain with a six-speed transmission.  If it was pointless on the 104Vdc street-bike, it must be doubly-so on a 325Vdc race bike, right?  As you could guess – I am not finding that the best performance comes from leaving the bike in one gear, however.

The transmission is simply a way to multiply torque to the rear wheel and provide a rider with an additional tool (clutch and gear ratios) to use.  If you're not particularly fond of, or good at, using a manual transmission on a gas bike or car, you'll probably not prefer it on an EV either. And even if you are, you might still decide that it's got no place on an EV as direct drive is ENOUGH.  It's nice to have the choice. 
« Last Edit: February 23, 2015, 12:02:06 AM by BrammoBrian »

Shinysideup

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Re: EV transmissions
« Reply #7 on: February 23, 2015, 01:14:26 AM »
Thanks for your interesting insights. Yeah, for some of us, "enough" is not enough!

BTW, I can find no trace of the Empulse HVR, either on this forum, on brammo.com, or on the Brammo FB page. Even Google couldn't find it. Did you spill some beans? ;)

roma258

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Re: EV transmissions
« Reply #8 on: February 23, 2015, 10:34:29 AM »
Seriously, spill a few more beans on the Empulse HVR please!

I think the fact that the the eMoto series is pretty much a single-model series for 2 years running does validate the gearbox approach to some degree. Now how that translates to the street is another question, but if there was no advantage to be gained, why isn't anyone fielding the Zero SR with its more powerful motor? The chassis can't be that much worse, can it?

Richard230

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Re: EV transmissions
« Reply #9 on: February 23, 2015, 10:55:09 AM »
I tend to look at electric motorcycles from a future consumer standpoint - where sales count the most.  I believe that not having a clutch and transmission on an electric motorcycle is the best approach to marketing them to new riders and expanding the customer base in the future.  Just compare the sales of manual transmission vehicles to automatic vehicles to show where customers are going. 

Now if someone made a CVT or some other sort of automatic transmission motorcycle, that would accomplish the same thing, that would work too.  But with electric motors, what would be the point, especially for an entry-level vehicle?  Right now younger people are not buying motorcycles and staying in the sport the way they used to.  I think the ease of riding, reduced impact on the environment, quiet and smooth operation, lack of much maintenance, reduced running costs and various other benefits will gradually increase the sales and popularity of electric motorcycles. But these benefits will take time to be appreciated.

While transmissions have a mechanical value, I think the lack of one will increase sales to new riders and that is where the future lies.  All that really needs to be done is to find some way to lower the purchase price and to have the major manufacturers get into the market (such as Polaris will be doing).

When I go  to BMW rallies, you would be hard pressed to find anyone under the age of 50 or 60.  That is not the future.  The future will be young people buying and riding electric vehicles - but it is just going to take some time and no one will be getting rich for a while (which is a real issue for a investor-driven company).

I am really going to be interested in seeing what Polaris does during the next few years with electric motorcycles.  Unfortunately (from my point of view), my guess is that they will go high-end, as they have with their other motorcycle brands, and this will limit any hope for volume sales.  Whatever happens the future should be very interesting for us early electric motorcycle enthusiasts.
current bikes: 2018 16.6 kWh Zero S, 2011 Royal Enfield Bullet 500 Classic, 2009 BMW F650GS, 2007 BMW R1200R, 2005 Triumph T-100 Bonneville, 2002 Yamaha FZ1 and a 1978 Honda Kick 'N Go Senior.

Ted Dillard

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Re: EV transmissions
« Reply #10 on: February 23, 2015, 12:32:27 PM »
BTW, I can find no trace of the Empulse HVR, either on this forum, on brammo.com, or on the Brammo FB page. Even Google couldn't find it. Did you spill some beans? ;)

It was in the thread that you commented on yesterday, responding to my question to Brian: http://brammoforum.com/index.php?topic=2877.0

The LITO Sora has a CVT.  A CVT doesn't offer discrete gears, but is not a one-speed, either.  If transmissions don't make sense for a modern EV, then why is LITO Green Motion betting their customers will spend a pretty penny on it?

Why indeed?  There are a lot of things on the Lito that are interesting, and unnecessary.  For their target market of "luxury EV buyers", it may be a good fit, though - time will tell.  Simply using their example to justify a CVT doesn't really hold water, though.  I can point to several instances of a CVT that have been dumped for EV use. 

I think the question we have to ponder before you answer this question is... "What is ENOUGH performance?".

I don't think this argument holds water either, now that we can see numbers from bikes like the Energica, the Mission, performance like the racing of the '14 Zero SR, your bikes, and a field of gas bikes.  The only argument that makes any sense to me at all is that of the choice being for the "rider experience".   Unless I missed something, when you compare performance between similar bikes with, and without a transmission it's a wash at best. 

Here's some reference: https://evmc2.wordpress.com/2013/04/27/transmission-questions-finally-answered-zero-brammo-comparison/

Here's another post re the Laguna Seca results ca. 2013: https://evmc2.wordpress.com/2013/07/21/transmission-debate-qualifying-results-at-laguna-seca-fim-err/

As with anything else in engineering and Physics, you can get to the same place any number of ways.  I have no problem with Brammo using a transmission, though I think the general consensus is that 6 speeds is more a function of what was available than what was best.  And I have no issue with riders wanting a transmission because they simply like it better. 

I don't, however, feel like anyone can point to one design or another and say it will give you better performance, and I'd truly welcome an education on it if I'm wrong.  As long as it doesn't include the phrase "torque multiplying"  ::)
« Last Edit: February 23, 2015, 12:48:25 PM by Ted Dillard »

RickXB

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Re: EV transmissions
« Reply #11 on: February 23, 2015, 03:04:51 PM »
I think for a given motor, multiple ratio will be superior over single ratio. Is it the only solution to increase performance? No . Since everything is a compromise between cost, time, weigth, volume, reliability etc.
they choose to go with the tranny because delivering a single ratio bike that doesn't meet performance expectation was not a option. HV was not an option either unless delivering 1 bike a month for 30k+$ is what you call a production bike. And finally it' not because tesla is not doing it that mean it's the only one solution. The 60-120mph is a tad sluggish for the asking price & probably my old IROC 86 350sbc have a better 60-120mph but nothing close to their 0-60. that's what i call compromise. Their is so few EV manufacturer that I don't think one company can say they found the perfect way to design an EV.

benswing

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Re: EV transmissions
« Reply #12 on: February 23, 2015, 03:07:26 PM »
The truth is that IF the Tesla had a transmission, the performance would be even more impressive.  The 0-60 time might not improve much due to adhesion limits of tires, but the top speed could certainly be increased.  So... it's not that the transmission was "useless", just that Tesla determined they could meet the minimum performance expectation for the majority of their customers (ENOUGH) to be happy without including the additional cost.

Also it was unreliable and kept breaking down. 

I agree that for the most part - the buying public is leaning towards a compromise of ease of use over outright performance in EV.  I am hopeful that there will still be those among us that continue to push for performance though as we show the way for what is possible.   

This seems to be the consensus in our little unplanned poll.  Most of the supporters of single-gear have been making the point that they get plenty of power for all their needs from EV's with a single gear.  The supporters of transmissions have been pointing to racing or squeezing out a bit more power in the lowest gear. 

There are costs and benefits to both, everybody does their own calculus to determine what fits their wants and needs. 

Thanks for your insight, Brian!

RickXB

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Re: EV transmissions
« Reply #13 on: February 23, 2015, 03:51:09 PM »
agree but when you cash out 15500$cad for a ZF9 , 17700$ for a ZF12 or 20000$ for a SR, I expect a bit more than a commuter. That kind of money is way north for a newcomer.16k for the Empulse R vs 20k for the SR, it was a no brainer to me. If you say same bike/same perfomance/same price but without a tranny, i will go without it but otherwise i'll stick with the shift

benswing

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Re: EV transmissions
« Reply #14 on: February 23, 2015, 04:08:19 PM »
16k for the Empulse R vs 20k for the SR

That must have been the fire sale.  Regular pricing for the SR was $1,000 less than an Empulse R.