ElectricMotorcycleForum.com
General Category => General Discussion => Topic started by: Low On Cash on January 22, 2017, 04:38:35 AM
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Advantages of Multi Speed Transmissions for Electric Motorcycles - Mike Mas
Hey guys - thought it would be a good topic to discuss the advantages of a using a 2-3 speed gearbox for or electric motorcycles. Its a proven fact that multi-speed transmissions offer an advantage of both range and performance.
Not too be misinterpreted - I’m perfectly happy with my single speed DSR Zero and understand the complexities and weight of using gear box. With that said - if Zero or any manufacture offered a new technology motorcycle with a 2-3 speed gearbox, I would be the first to get in line to buy one.
There are major advantages regarding performance and range when using a multi-speed gear box on electric cars, motorcycles and bicycles. Test have shown there is a 10-15% reduction in battery usage when using a 3 speed gear box in comparison to a single speed transmission.
While not applicable to motorcycles - there is new transmission technology called; MSYS, its a three speed transmission designed for electric cars to handle the torque of modern electric motors. The MSYS transmission uses “Cone Clutches†which offer many advantages over wet type multi clutches. These gear boxes are shown to operate at torque levels of up to 1500 ft. lbs. of torque, well above even Tesla’s powerful requirements.
(http://www.com-pany.com/zero/msys1.jpg)
(http://www.com-pany.com/zero/msys2.jpg)
As I previously mentioned, While Tesla uses a ZF single speed gear box, they realized there would be range and speed advantages of having a multi speed transmissions and spent time and money in an attempt to build one, however the project failed because of difficulties in manufacturing a transmission that could withstand the torque of their motor(s).
Typical Telsa Drive System
(http://www.com-pany.com/zero/tesla.jpg)
A company that was successful with multi-speed drives is BWM. On their BMW i8, Electric / Gas powered sports car, they drive the front wheels using a propriety motor and a GKN two-speed automatic gearbox. This transmission remains in the lower gear (11 to 1 ratio) while in “Electric Only†mode. Once the Turbo engine is started it then switches to second a higher gear (6 to 1 ratio). The two speed gear box allows exceptional “off the line†performance and improved high speed performance up to 155 mph.
BMW I8 Front Electric Drive w/ 2 Speed Transmission
(http://www.com-pany.com/zero/i8.jpg)
Back when Tesla was trying to develop a 2 speed gearbox, I always wondered why they just didn’t compromise and use two different ratios on their 4 wheel drive cars. The front could be a lower ratio and the rear would be a higher ratio. Since they operate on separate motors there would be no syncing of the front and rear sets. A processor would make them work in unison on acceleration then supply more or less power according to speeds. Off the line, the lower ratio would provide more work, then at higher speeds the low ratio front drive could be at idle or low power while the high ratio rear would provide the majority of power to propel the car. If BMW could sync an electric front drive and a turbo gas powered drive - then it would be a no brainer to make the multi ratio drive successful.
BMW I8 Chassis
(http://www.com-pany.com/zero/i8mech.jpg)
Its difficult to understand the advantages of a gear box with electric unless you have the opportunity to feel it for yourself. I say this because for close to 20 years I have been building and riding electric powered bicycles. With an electric powered pedal bike you have the distinct advantage to “Physically†feel the advantages when using a gear powered electric bike, verses a single speed.
The best way to describe this difference is to compare a “Hub Motor†bike system to a “Mid Drive†system. I’m sure some of the users of this forum have experience on electric bikes and will confirm the differences of a single speed drum motor verses a center drive.
Outlaw 1200 watt Hub Motor
(http://www.com-pany.com/zero/hub.jpg)
The Hub motor - Is mounted in either the front wheel or rear wheel or in some cases both wheels and somewhat like our Zero uses a fixed, single speed ratio. Hub motors are offered in two configurations which are both single fixed ratios. The more common hub motor has fixed magnets mounted to the outer shell of the hub motor. Another hub design uses a planetary gear system to reduce the ratio to allow the motor to spin faster for more starting torque, however both of these system are single speed fixed ratio systems.
Bafang 1000 Watt Center Drive System
(http://www.com-pany.com/zero/center.jpg)
The Center Drive system - This application allows the motor with a reduction gear to mount on the pedal tube with its own set of pedals. Instead of the chain going to the original sprocket, it now goes on the electric drive’s motor sprocket so the motor can power the bike or you can pedal or use both.
As shown on my Giant mountain bike images, this bike has been retrofitted with a center drive 1000 watt motor, (1400 watt peak) its self contained with an integrated controller and 9 IRFB3077 MOSFETs. This controller is fully programmable with your PC, or like the Zero, minor changes made on your dash controller. My bike is powered by a 48 volt 14AH pack that offers about 20-30 miles of range without peddling one stroke. These bikes are an absolute blast to ride and regardless of how steep the incline is they climb them with ease. These motors are available to fit most any bike.
My Giant Stance / Erad 1000 Watt Motor Drive System
(http://www.com-pany.com/zero/rad1.jpg)
(http://www.com-pany.com/zero/rad2.jpg)
(http://www.com-pany.com/zero/rad3.jpg)
The center drive has the distinct advantage over the hub motor since it uses bikes multi speed transmission (9-10 speeds mostly) for unlimited terrain advantages. In 1-3 gear, the bike has unbelievable (tractor like) power to climb and inclines up to 40 degrees or power thru sand or mud. Gear 4-7 are used for general bike riding or cruising at speeds 15-25 mph. In gears 8-9 (high gear) the bike is more geared for top speed now approaching 40-50 mph. You can shift the bike under full power since it has a shifter sense circuit which cuts the power momentarily as you shift.
Getting back to electric motorcycles and transmissions - To appreciate the advantage of different gear ratios, after you ride these electric bicycles for a period of time, you’ll develop a skill (physical wise) for the advantage of a multi-speed gear box as you’re peddling with the motor.
While were all aware a gearbox is not necessary for a an every day commute bike. For the guys who are hobbyist or looking for additional performance, a multi-speed transmission could offer numerous advantage. As an example, a lower ratio on our Zero would offer major advantages for off-road racing where where mud and sand are a factor on excessive draw on the motor & battery. If the bike was geared lower, the motor would be in its designed rpm and use less current. For the same reason on road applications where the bike is running at speeds at 100 mph, it would be advantageous to have a bike geared for this speed. As we all know, the “G’s†when snapping the throttle at 20-30 mph is considerable higher than that of 80-90 mph, that’s because we’ve reached the upper level of rpm’s the motor was designed for.
I’m sure the folks at Brammo had a least a few good reasons for designing the bike with a multi-speed transmission; one it would be more attractive to most bikers, and secondly offer an option for riders to select gears best for their riding environment and hopefully more range. Possibly where Brammo went wrong is by not designing a 3-4 speed transmission which would be more adaptable to an electric bike as the current 6 speed transmission in confusing and hard to shift for most riders.
(http://www.com-pany.com/zero/empulse.jpg)
In Closing - Maybe I’m way off here, but I have thought for years the best way to offer a multi-ratio on a motorcycles is on the rear wheel. Just how cool would it be to have a 2 speed gear box on the rear hub. The rear hub could have a planetary reduction gear system to lower the ratio then with a mechanical cable, you could lock it out and go back to the standard “1 to1†system like we have now.
Anyhow, at least for now, single speed transmissions are in and the slogan; “Less is More†fits the Zero’s design. What do your think?
Regards - Mike
(http://www.com-pany.com/zero/z1.jpg)
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I think one of the major reasons that you don't see a two-speed gearbox on an electric motorcycle is that there are none that a small manufacturer can just buy off the shelf that would be appropriate for the application. I am pretty sure that Brammo used a 6-speed transmission because that was all they could find that was already existing. Even then it was likely pretty expensive to have the manufacturer design a case to fit the gearbox components that would fit into their chassis. (I bet someone lost their shirt on that deal.)
Motorcycle gearboxes are a very specialized component and if you want to have a new one designed and manufactured for you a gearbox manufacturer is going to want to know that you will be buying thousands of them, like BMW does. They apparently buy their gearboxes from an established and experienced manufacturer. Other IC motorcycle manufacturers, like the Japanese brands, likely design and build them in-house.
I know that Zero considered installing a gearbox early on, but the weight penalty, friction losses, space requirements and especially the cost, steered them in the direction of direct-drive. I think they made the right decision. :)
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That's an interesting post Mike. This is what I think:
The engineers will design an electric motor to perform well up to and including motorway cruising speeds. I believe the torque and efficiency of the Zero motors only starts dropping off above 70mph. Above that speed you're wasting much more energy to aerodynamic drag compared to any reduction in motor performance.
The torque provided by an electric motor negates the need for gears. I'm more than happy with the acceleration of my DS for my commute. It feels strong from leaving the lights and I leave the cars behind without even trying. If I want more acceleration I can get a DSR or SR. 0-60 in under 4 seconds is lots of fun and plenty enough for all but the most determined speed freak.
So now we have a very elegant drivetrain that does the job well, why would we add complexity and give up all the benefits of not having a transmission?
There will always be special use cases where a transmission makes sense, but for the majority of people, most of the time, we're better off without one. I like the freedom of not having to change gears. It's a purer riding experience. It's like going back to the steam age when I have to use them.
Transmissions are needed to compensate for inferior motors, mostly those of the ICE era. That's my view.
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A CVT might be a compromise between the two.
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I'm sure more manufactures will experiment with gearboxes. Bigger companies like Honda will be working on electric bikes. They have the ability to produce an appropriate gearbox in house and the potential volumes to make use of it. They've never shied away from more complex experimental solutions.
Time will tell and I'm looking forward to when we have the choice. For now though, I think Zero have made the best call.
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That's an interesting post Mike. This is what I think:
The engineers will design an electric motor to perform well up to and including motorway cruising speeds. I believe the torque and efficiency of the Zero motors only starts dropping off above 70mph. Above that speed you're wasting much more energy to aerodynamic drag compared to any reduction in motor performance.
The torque provided by an electric motor negates the need for gears. I'm more than happy with the acceleration of my DS for my commute. It feels strong from leaving the lights and I leave the cars behind without even trying. If I want more acceleration I can get a DSR or SR. 0-60 in under 4 seconds is lots of fun and plenty enough for all but the most determined speed freak.
So now we have a very elegant drivetrain that does the job well, why would we add complexity and give up all the benefits of not having a transmission?
There will always be special use cases where a transmission makes sense, but for the majority of people, most of the time, we're better off without one. I like the freedom of not having to change gears. It's a purer riding experience. It's like going back to the steam age when I have to use them.
Transmissions are needed to compensate for inferior motors, mostly those of the ICE era. That's my view.
Thanks for the reply - I agree with you concerning the Zero’s design of simplicity which is one of its main attractions to most buyers. Coming from old school, while I appreciate the simplicity of the Zero, I would also like the option of a transmission to play with. Remember there is three classifications of riders; those who are dedicated to help the environment - those who just use their bike solely for transportation and those who like to experiment and tinker with new technology, I’m the later!
Regarding a transmission for motorcycles, as we all know, every motor is wound and designed for an optimum rpm range. We also know that if we keep the motor operating at that range of peak efficiency, it results in increased performance, less current and of course more range.
With that said, its important to note that unlike a gas engine, if we want more performance and range we can just easily add cells to achieve it. What trying to say is; if it cost a manufacture $1000 to install a tranny in a bike to achieve the range advantage, they might be better off just installing more cells to travel 10-15% further, since the weight and cost would be somewhat the same.
Lucky for us - with new technology in motors, controllers and cells the overall performance of the Zero now rivals and in many cases exceeds the performance of its ICE competition. The 0-80 mph performance of my Zero 17 DSR exceeds that of most crotch rockets, so we really don’t need more performance and at least for myself, I have no reason to travel at 100+ mph.
The biggest advantage for electric bikes is; if we did nothing other than keep replacing new advanced cells each year in the same Zero, our bike will weigh less, have more performance and more range.
Regards!
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For context, here is some background on this topic:
1) As you mention in your original post, transmissions have been attempted with electric vehicles and the tradeoff went badly:
http://www.autoblog.com/2008/01/23/breaking-tesla-has-a-solution-for-their-transmission-woes-get/ (http://www.autoblog.com/2008/01/23/breaking-tesla-has-a-solution-for-their-transmission-woes-get/)
2) Brammo had a transmission for their streetbikes, but eliminated it for their racing bikes. Rider Eric Bostrom mentioned how great the race bike was without gears:
http://www.cycleworld.com/2014/06/06/electric-vs-gas (http://www.cycleworld.com/2014/06/06/electric-vs-gas)
3) We have had this debate before (2-3 years ago in earnest) with input from the lead Brammo engineer who gave his reasons for putting gears in their motorcycles. Overwhelmingly the sentiment was that they offer more complexity and parts that can break down as a tradeoff for a minor improvement in acceleration, top speed and/or range.
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The single speed for me is superlative in very cold weather, when I drive with mitted hands that are much less agile with clutch levers than gloved hands are.
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A transmission allows quicker acceleration with a less robust system but isn't necessary in a commuter type bike. I considered putting one in my drag bike but went with more battery and a larger controller instead.
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Lightning and Alta Motorcycles are also single speed.
I would like to see a speed and efficiency plot of the Zero motor to see what the gains would be.
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I find it interesting that Lightning don't use gears and their range is 0-218mph. I wonder what the sweet spot of that motor is? There might be some clever stuff going on in the motor controller that compensates for different behaviors across the rev range.
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Lightning and Alta Motorcycles are also single speed.
I would like to see a speed and efficiency plot of the Zero motor to see what the gains would be.
I recall reading several years ago that gears would improve efficiency of electric motors by up to 16%. (Not enough benefit for the tradeoff.)
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If an electric bike/car has enough torque to spin the back wheel and still go 300 km/h what advantage would gears make?
All they would do is slow you down because it takes a moment to change from one to the next.
There is more drive line losses with a gearbox, so extra range is debateable based on the power/torque of the motor.
If the motor is weak then a gearbox helps, but it is much easier and cheaper to use a bigger (more powerful) motor.
Tesla went back to the drawing board and designed a better controller mitigating the need for a gearbox. They have had plenty of time to design a 2 speed box ( for the model 3) but have chosen not to.
There may be studies but how old are they and what where the motor/controller parameters?
If the motor is running in an efficient part of its rev range gears will give less range. There are so many variables to range, speed of the motor is the most important.
Reno in formula e has built there best car yet, searching for range and speed and it has no gears (or 1 if you like) they built a better motor/controller so it doesn't need gears.
I love my electric bike because it doesn't have gears.
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If an electric bike/car has enough torque to spin the back wheel and still go 300 km/h what advantage would gears make?
All they would do is slow you down because it takes a moment to change from one to the next.
There is more drive line losses with a gearbox, so extra range is debateable based on the power/torque of the motor.
If the motor is weak then a gearbox helps, but it is much easier and cheaper to use a bigger (more powerful) motor.
Tesla went back to the drawing board and designed a better controller mitigating the need for a gearbox. They have had plenty of time to design a 2 speed box ( for the model 3) but have chosen not to.
There may be studies but how old are they and what where the motor/controller parameters?
If the motor is running in an efficient part of its rev range gears will give less range. There are so many variables to range, speed of the motor is the most important.
Reno in formula e has built there best car yet, searching for range and speed and it has no gears (or 1 if you like) they built a better motor/controller so it doesn't need gears.
I love my electric bike because it doesn't have gears.
You nailed it on all points, particularly when you say "If the motor is weak then a gearbox helps...". Gearboxes are crutches for engines that can't operate down to 0 rpm and/or which have lousy torque at low rpm...a category which ICEs fall squarely into. Decades ago, when they were designing the first diesel-powered locomotives, they realized that designing a clutch and/or torque converter that could handle that kind of weight, to allow the diesel engine to start and stop the train, wasn't going to work, so instead, they created the diesel/electric hybrid. The diesel engine runs a generator which is used to power the electric motors. Since electric motors are perfectly happy at 0 rpm, no transmission, clutch, or torque converter is required. The diesel can idle when the train stops and run at its most efficient or most powerful rpm at other times.
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I'd prefer a clutch to be honest.
When the backside kicks out it's nice to be able to disengage the spinning mass from the rear wheel. :)
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If electric motorcycles had a gearbox, the next thing you know an "oil thread" would be created on this forum. :o
A great reason for not having a transmission. ;)
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I'd prefer a clutch to be honest.
When the backside kicks out it's nice to be able to disengage the spinning mass from the rear wheel. :)
I agree. Especially since we have no traction control on the Zero. But wouldn't be worth a whole transmission just to get that ability. The next option would be to add a clutch just for the single gear but sadly I doubt Zero has the R&D to design considering the short list of benefits.
I thought about wiring up a lever and tying it in to the motor kill switch to create an electronic version to just be able to cut power faster than I'm able to with the throttle. But I'm not sure how effective it would be at mitigating a low side and it would take a second once re-engaged to get power again which would be annoying at the least.
Sent from my Nexus 6P using Tapatalk
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It seems like traction control would be a lot easier to implement than adding a transmission and a clutch.
There is a lot of user error when people shift gears and clutch. You can hear the errors in lots of Youtube videos.
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I'd prefer a clutch to be honest.
When the backside kicks out it's nice to be able to disengage the spinning mass from the rear wheel. :)
There is almost no spinning mass compared to an ICE. Let go of the throttle and the regen will actively counter the spinning mass.
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I'd prefer a clutch to be honest.
When the backside kicks out it's nice to be able to disengage the spinning mass from the rear wheel. :)
There is almost no spinning mass compared to an ICE. Let go of the throttle and the regen will actively counter the spinning mass.
Good point, I wonder how close the spinning mass of the output side of the clutch compares to the rotor of the motor, I'd imagine there is not a great deal in it, and as you say, the output side of a clutch cannot act as a counter the way a motor in regen mode can.
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My thoughts: Back in 2013 when I bought mine, I'd still have chosen a Brammo because of the look and fit and finish looking cleaner and more refined. The transmission wasn't really a selling point for me, but I do see the merits. I'd likely go with a Zero today, though not because of direct drive, but because of it's range and performance. In the end, it didn't really matter to me.
So, a lot of posts about direct being better than transmission, but is that really true across the board?
Torque on the Brammo R is 90Nm and it has 54HP. Zero SR has 144Nm they have 67HP. One decided to go with a slightly larger motor with more torque and direct drive it, the other decided to put a smaller motor and a transmission to get them the torque they wanted, but over a larger vehicle speed.
Yes each have their benefits. The Zero (aside from belt) is pretty much zero maintenance and more efficient in its conversion of torque to the rear wheel. The transmission has infrequent transmission oil changes, and likely no need to change the clutch. It's less efficient, but allows you to always put the motor in it's more efficient RPM range, something direct drive cannot do (at least not at all speeds).
I did some calculations on the torque on a Zero SR and Brammo Empulse R:
Here's the Zero:
http://electricmotorcycleforum.com/boards/index.php?topic=3872.0 (http://electricmotorcycleforum.com/boards/index.php?topic=3872.0)
Here's the Brammo:
http://electricmotorcycleforum.com/boards/index.php?topic=3871.0 (http://electricmotorcycleforum.com/boards/index.php?topic=3871.0)
The Brammo has a smaller motor with 90Nm of torque peak. Notice the Brammo has 2760N of force at the rear tire (where the rubber meets the road) in 1st gear from a stop.
The 2014 Zero SR, had a little larger motor (bigger diameter) with more torque at 144Nm. Notice here that the peak torque on the rear rubber is 1983N. Even with the newer motors and 157Nm of torque and a 4:1 ratio (before it was 4.4:1), you get 1966N of torque at the rubber (slightly lower than 2014). In fact, the Brammo has mote torque at the rear rubber than the Zero SR (2014 until today) in 1st and 2nd gear. 1st gear has ~775N more force and 2nd gear has about 275N more.
Not poo-pooing Zero at all, but there are merits to a transmission.
Transmission Pro:
Can get the motor in it's peak efficiency RPM
Can change torque output on the rear wheel
Transmission Cons:
Less efficient (but could actually pick up gains by putting the motor in it's peak effieincy part of the motor curve)
More maintenance (but minimal in my experience)
More moving parts
More expensive (We're all guessing here though, is a larger motor and direct drive cheaper than smaller motor and off-the-shelf transmission?)
Transmission lash is noticable
Direct drive Pro:
More efficient
Less Maintenance
Less moving parts
Direct drive Cons:
Cannot change the torque output on the rear wheel
Can potentially lock up the rear wheel if there's a catastrophic motor failure
Cannot put the motor in peak efficiency (which could, in theory negate any gains made by direct drive)
Anyway, this is just using the specs on each, there's nothing to argue here. Just fact and showing some of the pro's and cons of each.
I'd by a Zero today if I was looking for a bike, because of the range and support and refinement the last few years, not because of the direct drive.
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Frodus
Thanks for the detailed reply and most important, sharing the torque advantage comparisons using a transmission - Your Rear Wheel calculations clearly shows the torque advantages of using a transmission. It boils down to the fact any motor will be more efficient and powerful at its designed operating RPM.
Do we need a transmission - possible not, but just because Zero decides not to use one, which I’m sure was from a cost stand point, does not mean others will follow. Brammo did get one thing right - guys like shifting gears.
As an example - The best motorcycle transmission in the world, which I own two bikes with; is the Honda DCT (Dual Clutch Transmission) The DCT is a 6 speed computer controlled transmission that may be shifted manually as well. The DCT is the most efficient and the fastest shifting transmission made. By using one clutch for 1,3,5 gears and a second clutch for 2,4,6 gears, it allows the transmission to shift from one gear to another by simply releasing one clutch and engaging another, its lightning quick since its actually in both gears at one time prior to shifting. Testimonial to the fact just how good the DTC is; is used by many luxury and sports such as the Porsche 911, Mercedes GT-S, BMW M4, Alfa Romeo 4C, Acura NSX, and others, some costing over a million dollars since it is the most efficient (no hydraulic converter) and can shift faster than any human being or any hydraulic transmission.
Getting back to my point - even though this transmission is the most advanced in the world - Guess What? it was never accepted by the motorcycle industry for the simple fact that riders like doing stuff when they ride and shifting is one of them.
Thanks - Mike
This is the Honda NM4 Limited Production bike with the their DCT system - because of its aerodynamic design and efficiency of the Dual Clutch Transmission and engine this bike achieves up to 80 miles per gallon.
(http://www.com-pany.com/zero/n13.JPG)
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My Honda dealer says that the DCT transmission has increased their Honda sales considerably. They claim that new riders don't want a manual transmission, or the need to shift or operate the clutch. They are much happier with an automatic transmission, which makes motorcycles much easier to ride, especially in urban traffic. Personally, I like not having to shift my Zero, after shifting motorcycles for 55 years. It just makes the ride more enjoyable for me. :) One of the reasons that I bought a Zero instead of a Brammo when the Empulse finally hit the market was because it had a 6-speed transmission and I preferred the simplicity of the Zero design. :)
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Also zero isn't the only EV manufacturer to use a single gear. All of the major manufacturers of EVs use it. So this isn't a Zero Motorcycles simplicity thing, it's the industry standard for a reason.
Not that there aren't advantages, and I appreciate the detailed analyses provided here. Very interesting.
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Also zero isn't the only EV manufacturer to use a single gear. All of the major manufacturers of EVs use it. So this isn't a Zero Motorcycles simplicity thing, it's the industry standard for a reason.
Not that there aren't advantages, and I appreciate the detailed analyses provided here. Very interesting.
Exactly, the reason they chose it isn't necessarily performance (maybe cost and simplicity driven?). And to your point, Brammo isn't the only EV manufacturer that has used a transmission, and likely won't be the last. Just different manufacturers solving an end goal with 2 solutions.
Also, if I recall correctly, Tesla had a terrible time not breaking transmissions with all that electric motor torque!
#ilovemybrammo
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If electric motorcycles had a gearbox, the next thing you know an "oil thread" would be created on this forum. :o
A great reason for not having a transmission. ;)
Now that's funny . . . and true! Every m/c forum I've ever been on had at least one oil thread going at any time. On the H-D forums there were more like 3 or 4, each dumber than the last one.
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My first shift-less bike was the Honda Silverwing scooter. It was positively liberating, especially in city traffic. It was kind of slow "off the line" but the Zero certainly doesn't have that problem. 😀
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If electric motorcycles had a gearbox, the next thing you know an "oil thread" would be created on this forum. :o
A great reason for not having a transmission. ;)
Now that's funny . . . and true! Every m/c forum I've ever been on had at least one oil thread going at any time. On the H-D forums there were more like 3 or 4, each dumber than the last one.
Your choice of IC oil is apparently like your choice of a religion. :o I have no idea why? ??? Perhaps it is all just a big plot by Big Oil. ::)
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The funniest part is that once you understand a bit of the science behind the oil, instead of "ONE OIL TO RULE THEM ALL" you can just go "anything in this group is fine for X application"... and thats that. You never need to look at an oil thread again.
So, just dedicate 2 years of your life to the subject, and you never have to read a forum thread about it. Problem solved.
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- Riders like doing stuff when they ride and shifting is one of them
- They are much happier with an automatic transmission
- 25 years ago, riders wanted to "kick" start their bike, electric gadgets are too girly
- Now they all have electric starter
- sure, ABS is for non-riders only
- sure, really?
Other domain, but same "male self-esteem" issue
- 25 years ago, the pro photographers said "autofocus is for tourists, true photographers want to decide with their own hand how to set the sharpness"
- Now the pros' are comparing the AF performance of high-end cameras, and always moaning when the AF is not as perfect and fast as they expect...
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I've spent the last two weeks back on an ICE bike while my DS is awaiting a new rear wheel.
I'm enjoying using a clutch and gears, even though much of my commute is stop/start in traffic. However, I know that I'll be much happier when I'm back on my Zero.
Gears give a little reward every time they're changed. There's the feel of clicking into gear, which is especially nice with a smooth box. Then there's the change in engine note, which I'm sure makes people feel like they're paying a musical instrument. The reward is greater when we get it just right. It's engaging, rather like pulling the arm on a slot machine, rather than pressing a button. It helps give the bike it's character and there are many other tiny little things that make changing gears a pleasurable thing to do.
I'm willing to sacrifice all that for the perfectly smooth acceleration from a direct drive. All that faffing around with a clutch and gears just seems unnecessary and quaint to me now. Hitting the rev limiter is a nuisance. Hearing an engine scream just seems like a lot of fuss about nothing. I love the effortless torque from my Zero. I can ride fast and not attract any attention. I adjust the torque with a twist of my wrist. Nothing else required.
No gears is just more freedom to enjoy the ride.
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Hey guys - While I’m pretty sure Zero is going to keep their direct drive for a while, maybe in the future we’ll see high-tech electrics bikes use transmissions to obtain additional range or use a transmission for high speed track use or low gear performance for off-road bike racing.
As we all know, the most efficient transmission is one with standard gearing. CVT’s have their limitations and automatic’s have loss from slippage since they work on a hydraulic principle. It’s for this reason the dual clutch transmission was developed, they are somewhat simple in design, have the worlds fastest shifting and their operating system has the lowest loss of any transmission made. Until recently, DTC’s were only found in high-end Sports cars like Porsche 911, Mercedes GT-S, BMW M4, Alfa Romeo 4C, Acura NSX, and others since the DCT has no power loss, shifts faster and smoother than any human driver can.
(http://www.com-pany.com/zero/dc4.jpg)
In the past, some car manufactures used DCT’s but had quality control problems, but now DCT’s are making their come back in new vehicles like Ford and of course Honda Acura with its 8 speed DCT. I have heard that Honda spent over 100 million in development of the DCT so its pretty damn neat when you can jump on a bike like my Honda NC700 which I only spent around $8500 and have this technology. I presently own two bikes with DTC, a Honda NM4 and Honda NC700, after owning them for years, they still amaze me with their performance and technology.
Here’s how they work, first off there is no clutch lever or mechanical foot lever. On the right bar there is a button which has Neutral, Drive and Sport. when you move the switch to Drive, nothing happens until you add throttle. Drive is like an Eco Mode so the computer shifts very quickly to conserve fuel, at 38 mpg you’ll be in 6th gear if you use moderate throttle. My NC700 gets 60-65 mpg. and my NM4 with its aerodynamics gets 85-90 mpg with its 700cc 2cyl engine.
The more throttle you use the longer and further the processor will hold the shifts since it know you’re looking for performance rather than economy. It also has a kick down feature, if you’re in say 4th, it will downshift to 3rd or even 2nd if you open the throttle. The next mode is; Sport Mode, on the 2017 models there is a choice between three different Sport modes. In Sport, the transmission pretty much shifts as if you were driving a sport bike, it hold the gears longer and the engine rev’s much higher. Since its oriented on performance it won’t shift in to 6th gear until 60 mph.
Manual Shifting - If you like, you can choose “Manual Only†shifting - on the right handle there is a manual button which allows you to shift the bike manually with two levers on the left side of the bar. You can also downshift the bike as well. If you forget or just lazy, the processor will downshift the transmission for you. Another function of the manual levers is; if you are in the Drive or Sport mode and you decide you want to shift up or down a gear, you can hit the manual lever and it will shift the bike into that range.
In brief here’s how the transmission works, let’s say your in 1st gear then you want to shift to 2nd gear, At the “moment you shift†there is no mechanical gear shifting taking place from 1st gear to 2nd gear, both gears are already fully engaged and what happens is; it releases the clutch for 1st gear and engages the clutch for 2nd gear.
Honda’s DCT system incorporates two clutches, Clutch 1 is used for starting off and also controls odd number gears 1st, 3rd and 5th gears. Clutch 2 controls 2nd, 4th and 6th gears. The bikes processor controls the two clutches to operate in sync with each other in making gear changes. When the computer or rider changes gears, at the moment the shift takes place, the processor simply disengages the first clutch then engages second clutch or vice vera.
Regards - Mike
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Somewhere online - and I it wasn't in English. So keywords haven't helped me.
I'm not sending anyone to look - I've tried for a few hours to bring it back into my history.
In case someone more gear knowledgeable already has it.
It was a 2 speed electric motorcycle/bicycle transmission.
It appeared to me as a planetary gear with a brake disc on the planetary.
Engage the brake caliper and the ratio changes to HIGH
So no synch, basically one wearing part. Simple small and capable of handling torque.