Brammo Owners Forum
Brammo Empulse Discussion => Brammo Empulse => Topic started by: Richard230 on April 26, 2013, 04:56:50 PM
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Finally we have a direct comparison between the two motorcycles. No surprises here though. The Empulse is the better sportbike and the Zero is the better commuter. The Empulse accelerates faster and has a higher top speed, while the Zero will travel further on a single charge. The Empulse handles better and the Zero is simpler to maintain. The consumer gets a choice, which is always a good thing. :)
http://www.motorcycle.com/shoot-outs/2013-brammo-empulse-r-vs-zero-s-zf114-91574.html (http://www.motorcycle.com/shoot-outs/2013-brammo-empulse-r-vs-zero-s-zf114-91574.html)
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Nice review. I'm glad someone finally did it! I'd love to ride the ZF11.4
Agree with most of it. I think 3 gears would be just fine..... I use 2nd, 3rd and 5th most.... but I have used 4th and 6th at speed to keep my kW useage below 8-10kw. I think the transmission slack is acceptable.... it's just different.
I think it would depend on the gear you're in at 55 for the Zero to overtake the Brammo.... mine pulls pretty hard at 55 in Sport mode depending on the gear I'm in.
Good review though, glad they did it!
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I think it would depend on the gear you're in at 55 for the Zero to overtake the Brammo.... mine pulls pretty hard at 55 in Sport mode depending on the gear I'm in.
Interesting that they tested the 50 mph throttle while in 4th gear. I wonder how it would have fared against the Zero in third.
Agree that it's a decent review for the most part.
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There is a bit of a learning curve with the Empulse
I don't shift out of first till 45mph...
55 in 4th? Heck, at 55mph I am just "thinking" about shifting into 3rd..
As for 6 gears...yeah it's a bit of overkill for me...but really you should only be in that 6th gear when you hit 90...and it is what M/C drivers are use to..
G
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3rd gear @ 55 mph is the sweet spot for both efficiency and power. With an 8000 (or is it 9000?) RPM redline you can stay in 3rd gear up to 90 mph, though you'll get more efficiency and power if you upshift to 4th around 65 mph.
Part and parcel of offering a choice to an operator is the possibility of making the wrong choice. With the Zero you're always ;) in the right gear.
I suspect the power delivery on the motor may trip up new Empulse riders. When the power peaks .. or plateaus .. at 5000 RPM, the motor may feel like a tapped out gas engine. Experienced gas riders may choose to upshift at that point to get to an RPM range where power builds with RPMs (3000-4000 RPM), even though the lower RPM range offers less absolute power and efficiency than the lower gear.
At least, that's what I think without having ridden the Empulse. How does that sound to our Empulse owners?
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I agree with your assumption, Promotech. I've never hit the rev limit on the Empulse, I always find myself shifting sooner despite knowing it may not be the best way.
I'll add that I would LOVE a parking brake!
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I think 4th gear is was a good choice. I don't think they were looking for which bike accelerated the quickest from 50mph. I think they were trying to more directly compare motors. My guess is that they felt the Brammo in 4th was close to the Zero's gearing. Given the weight difference and slight peak torque advantage, only a slight edge given to the Zero I think says a lot about what Brammo has done.
And all you folks shifting the R around 5k while riding it hard, I think you're right to do that. That's about where Shelina shifts on the R and TTX. The regular Empulse you will wring out like and ICE bike.
"With the Zero you're always ;) in the right gear." Well, the only gear, anyway.
I was surprised the Brammo was said to leave the Zero in the dust off the line. Not what we heard from the early Zero reports. I'd still like to see 0-60 and 1/4 mile times.
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My impressions...
The Empulse R motor is funny...when you get in the sweet spot, 4500 to 5500 RPGs, the engine is almost silent, smooth and effortless. You almost hate to shift out of it.
For most of my commuter riding I leave it in 1st.
Gavin
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I think 4th gear is was a good choice. I don't think they were looking for which bike accelerated the quickest from 50mph.
I beg to differ: I think they WERE looking for which bike accelerated the quickest form 50 mph! The article said:
"A roll-on contest at 55 mph (with the Empulse in fourth gear) showed the Zero has a slight edge.”
In my book, a roll-on contest IS looking for which has the better acceleration.
Speaking as someone who has almost 4K on the the Empulse, most of which is on the freeways, 4th gear at 50 mph FOR A ROLL-ON CONTEST, is simply the wrong choice. In Sport mode, peak power is at 6000 rpm. Since 5000 rpm in 2nd gear gives me about 50 mph, that's the gear I would have chosen for this contest, shifting to 3rd somewhere between 6000 and 7000. Surely prospective bike buyers are interested in the performance of the bike as a whole, not just some subset such as characteristics of their respective motors.
Bottom line, I think the article is very misleading on this point, probably because the authors just didn't have enough experience on the Empulse to select the most appropriate gear. Most probably, 4th gear "felt about right" to a rider whose experience was coming from the ICE world. These bikes love to rev and stay in the upper part of the tach. It took me a few weeks of riding to really get that.
Otherwise, I thought it was a useful article.
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In my book, a roll-on contest IS looking for which has the better acceleration.
A lot of motorcycle magazines would do "top gear roll on". I think many manufactures would design their gearbox to improve the top gear roll on tests. That use to drive me crazy because I wanted better gas mileage using top gear. My Vstrom 650 has six gears... if I need speed I could always go down to 5th, or just leave it there if it needed it.
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Even Consumer Reports does roll-on acceleration tests with the cars that they test, so it seems to be a standard in the industry. However, I have never been quite clear how they test an automatic transmission car (like most that they evaluate) against a manual transmission car. With an auto transmission I assume that it will downshift into the lowest appropriate gear for the speed traveled, while they would have to select a particular gear for the manual trans. I assume that they select a lower appropriate gear before stepping on the gas, but I am not sure about that.
Most motorcycle magazines seem to test their bikes using a top gear roll-on. I think they do that because either most riders will likely not shift when accelerating at high speeds in an emergency (as they are too busy thinking of other things) or just because it gives the reader a feel for the bike's mid-range pulling power.
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I take that article's claims of the 50mph roll on test with a grain of salt. It could be true, which is fine, but they lack detail for anyone to verify it's accuracy. I think you could likely find a gear that you would out-accelerate the Zero at 50mph, and that is exactly why having a transmission is nice.... because you have a choice of multiple gears. That allows you to do a few things: Put it in a high-efficiency range of the motor and get further or put it in a high-horsepower range and accelerate faster.
I think the difference in ranges has a little to do with battery capacity (10kwh versus 9.3kwh), a little to do with weight (accelerating a heavier bike uses more current).... and a little to do with the transmission (although likely less than 10% for gear/chain losses... ).
All in all, I love my Empulse R, always will and there's not an article out there that will get me to think otherwise. It's a great fit for me and meets and exceeds my needs. I'm done and will spend my time riding, rather than discussing transmission or differences between the two. :)
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I think you could likely find a gear that you would out-accelerate the Zero at 50mph, and that is exactly why having a transmission is nice.... because you have a choice of multiple gears. That allows you to do a few things: Put it in a high-efficiency range of the motor and get further or put it in a high-horsepower range and accelerate faster.
Those two are the same gear almost all of the time, no?
I think the difference in ranges has a little to do with battery capacity (10kwh versus 9.3kwh), a little to do with weight (accelerating a heavier bike uses more current).... and a little to do with the transmission (although likely less than 10% for gear/chain losses... ).
BrammoBrian dropped a comment on ESBK to point out that the Empulse was ridden harder than the Zero.
http://esbk.co/2013/04/28/first-moto-rag-empulse-r-vs-zero-s-zf11-4-comparo-via-motorcycle-com/#comment-1521
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maybe same gear.... how about I change to "peak efficiency" or "peak torque" since that's really what we're looking at.
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Also, to be accurate, they need to run the same tests on a dyno....
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I doubt people are choosing between the Zero and the Empulse based on which one wins a race either off the line or from 50-80 mph. I test rode the Zero S and gotta say, the acceleration from 50-80 is pretty exhilirating. When it comes to that particular aspect of riding, neither bike will leave riders wishing they were on ICE.
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Here's something I found interesting..... I was Looking at the Zero DS ZF11.4....
126mi city
82mi combined
61mi highway @70mph
The gearing, controller and motor are all the same. The only real differences I see are the DS tires and different suspension. The DS is 8lbs heavier.
So the kWh/mi for the Zero DS ZF11.4 is:
10kWh/126mi = 79.4Wh/mi city
10kWh/82mi = 122Wh/mi combined
10kWh/61mi = 164Wh/mi combined
And the kWh/mi for the Zero S ZF11.4 is:
10kWh/137mi = 73Wh/mi city
10kWh/93mi = 107.5Wh/mi combined
10kWh/70mi = 142.9Wh/mi combined
And we have the Brammo Empulse R/E1:
9.3kWh/121mi = 77Wh/mi city
9.3kWh/77mi = 120.8Wh/mi combined
9.3kWh/56mi = 166Wh/mi combined
For City, Zero S to DS jumps from 73Wh/mi to 79.4Wh/mi on city, and from 142.9Wh/mi up to 164Wh/mi for highway at 70mph.
That's a bit surprising. Do dual sport tires really cause that much drag that would put the DS into the same range category as the Empulse?
Something smells a little fishy.... That's an ~9% increase in Wh/mi useage in city, and a whopping 15% increase on the highway.
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In 2012 I think the DS had a different final drive, but the specs are the same for 2013. The DS tires are higher profile on narrower rims. I know how to calculate circumference for a car tire, but not sure how the rounded nature of a motorcycle tire might change that formula (not to mention the change in rim width). Could the tires have different circumference and thus implicitly modify the effective final drive ratio? They have the same top speed so I would guess not...?
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Zero DS: 132T / 28T, Poly Chain® GT® Carbon™ belt
Zero S: 132T / 28T, Poly Chain® GT® Carbon™ belt
Same final drive.
Tire Diameters for the rear:
DS: 130/80-17 (25.189" diameter)
S: 130/70-17 (24.165" diameter)
So there's a ~1" larger diameter on the rear... that shouldn't change things that significantly.... that would really only effect acceleration .... but 9% and 15% for city/highway? That's a huge change for a different aspect ratio and some Dual Sport tires.
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Frodus, you're assuming that the tire sidewall extends vertically from the wheel rim as in a car (well, 99% of cars), but it does not. As I said, I could apply the standard formula which works reasonably well for a car, but these are bikes with a rounded profile and sidewalls that extend at an angle from different sized rims. I don't think the standard tire math even gives you a "rule of thumb" estimate of their actual diameters.
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I think the greater wind resistance of the DS, compared with the S, might account for much of the difference. The DS has a seat height that is 3" taller than the S seat. The greater frontal profile of the DS could make the difference at high speeds - along with the increased rolling friction of the aggressive dual sport tires mounted to the DS.
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Frodus, you're assuming that the tire sidewall extends vertically from the wheel rim as in a car (well, 99% of cars), but it does not. As I said, I could apply the standard formula which works reasonably well for a car, but these are bikes with a rounded profile and sidewalls that extend at an angle from different sized rims. I don't think the standard tire math even gives you a "rule of thumb" estimate of their actual diameters.
You assume I'm assuming :)
I calculated those diameters based on the aspect ratio. The aspect ratio takes into account the ratio of width and height. Those are true diameters that I have verified using several online motorcycle tire diamter calculators. I've also verified this with my old VFR tires.
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I think the greater wind resistance of the DS, compared with the S, might account for much of the difference. The DS has a seat height that is 3" taller than the S seat. The greater frontal profile of the DS could make the difference at high speeds - along with the increased rolling friction of the aggressive dual sport tires mounted to the DS.
Good point Richard!!! Forgot about that.
That 3" height is almost all tires/wheels/suspension... the bulk of the bike stays the same. With that 3" height and lets say a 130mm width of the rear tire (~15") is roughly 45in^2 more frontal area. Lets kick that up to 60in^2 for good measure because if you do increase front height, you may increase the body cross sectional area a bit... but not by much.
Lets say the Zero itself is 500in^2 of frontal area... it should be close. I threw the values in my old elmoto calculation sheet with a 500 and 560 in^2 cross sectional areas, 0.8 Cd at a 70mph cruise. The drag Coefficient on these is going to be fairly bad since they're unfaired.
96.71Wh/mi for 500in^2 and
106.5Wh/mi for 560in^2
So a ~10Wh/mi change.... and it's right around 10wh/mi for other cross sectional areas I tried... like 400/460, 300/360
Looking at the Zero DS and S (166Wh/mi and 142.9Wh/mi respectively).... frontal area would account for 10wh/mi .... the actual difference is ~23wh/mi... so that other 13Wh/mi is coming from somewhere.
So yes it does effect the wattage useage some. I'd guess that less than 1/2 of that increase is due to increased frontal area.
It's amazing what you can do with just changing the rolling resistance of the tires and your cross sectional area..... tucking sounds better doesn't it :)
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Luke (liveforphysics) who seems to be in the know about Zero motorcycles had this to say about the differences in performance between the DS and the S on the elmoto forum:
You're aware one bike uses a Sevcon Gen4 size6 and one uses a Sevcon Gen 4 size4 right?
So how would a size 6 and a size 4 affect the range of similar motorcycles and why? I can see how a larger controller would increase top speed and acceleration, but maximum range?
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I think he means that the Brammo uses a Sevcon Gen4 Size 6 and the Zero S and DS both use a Sevcon Gen4 Size 4. He commented on an earlier post than mine, not my S versus DS posts.
According to Zero's site, and from what I've been told, both have a "High efficiency, 420 amp, 3-phase brushless controller with re-generative deceleration"... meaning both of the Zero S/DS bikes use the Sevcon Gen4 Size 4.
And it could effect the acceleration if you threw a Gen4 Size 6 in a Zero. It would be allowed to draw more current from the batteries during heavy acceleration, which could potentially limit the max range. If you floor the throttle in an ICE, you use more gas, and get worse gas mileage.... same thing here.
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Makes sense. :)