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[manlytom]

hi Neal, good to see you back

so the Empulse seems to go for both, aerodynamics and gears ! so she gains in aero and looses again with the gears. I so far like the relative simplicity of electric motorcycles. Can we keep it like that ? With the Zero's I have been riding for over 2 years now it has been fun and simple - yet they could have much better aero dynamics to see them gain efficiencies at high speeds. So for gears we loose 5% with aero what is in it ? I.e. the lower seat on  Zero S and changed fairings ? how much would we gain ?

[Neal_Saiki]

Both the Brammo and Zero bikes have upright riding positions and you can't really make them very aerodynamic.  I'd say it's a wash between them.  The brammo is less tall, but it's wider.

Aerodynamic drag is huge, but it's very difficult to get it reduced.  The only sure fire way is to reduce the frontal area.  I'm a big fan of making narrow bikes with the rider's legs tucked in so the frontal area is minimal.  Having low handle bars really helps reduce drag, but my back hurts riding like that.

Aerodynamically the most important part of the bike is the back end.  The important part is to smoothly bring the air back together again after it's split around the bike.  Screens and stuff on the front really don't do much to reduce drag.

The Hayabusa is one ugly bike, but it sure is aerodynamic.  Look at the tail secion, it's actually a little higher than the tank.  That does wonders to reduce drag, but then it's hard to throw a leg over and it's like you are sitting in a bucket.

Neal

[manlytom]

good points Neal, forgot about the Rear end effects ... in the Zero threads we seem to have some members gaining 10% or so on range and top speed with front screens. For 10% worth while to consider I guess and as we go into winter it keeps the air of the chest ...

[Richard230]

My solution to motorcycle aerodynamic drag is to just follow the speed limit. That solves most of the problem and will extend your range significantly.  In my case, I use my motorcycles primarily for daily transportation and if I need to be somewhere in a rush, I just leave earlier.   

[protomech]

Or the mileage claims by Honda for their Insight that resulted in a class-action lawsuit, which was widely reported in the press and no doubt did nothing for the sales of that model car.

The lawsuit was for Honda Civic Hybrid owners after a software update reduced the usable capacity of the battery (small impact on mpg).

The 1G Insight was a $20k efficient 2 seater that launched in a time of $1.20 gas. I drive one, it's fantastic personal transport and an engineering marvel, but I can see why they failed to sell. My lifetime mpg average is about 68 mpg and all I do is drive carefully.

Both the Brammo and Zero bikes have upright riding positions and you can't really make them very aerodynamic.  I'd say it's a wash between them.  The brammo is less tall, but it's wider.

Zero claims 43 miles @ 70 mph constant for the Zero S, 184 Wh/mile. Brammo claims 56 miles @ 70 mph constant for the Empulse R, 166 Wh/mile.

If the gearbox imposes an additional 5% efficiency penalty, then a fixed-gear Empulse would do about 158 Wh/mile, about 18% more range/kWh than the Zero. If aerodynamics are basically a wash, do you think that's due to operating the motor at a more efficient point, inefficiencies at high load for the Zero, flawed test design, or something else?

[ColoPaul]

Zero claims 43 miles @ 70 mph constant for the Zero S, 184 Wh/mile. Brammo claims 56 miles @ 70 mph constant for the Empulse R, 166 Wh/mile.

I'm confused:  Zero claims 43 miles@70 mph for the ZF6:  That's 6000Wh/43miles or 139 Wh/mile.   The ZF9 is 63 miles @ 70 mph; 142Wh/mile.
Where did you get 184 Wh/mile?

[Richard230]

I heard on the news yesterday that the Honda Insight small-claims lawsuit, where the owner received a judgement of almost $10K , was tossed out by the Superior Court, due to the mileage claims following the government testing standard (or something like that).

As far as rolling drag between the Zero and the Empulse goes, my money is on the Zero. It is thinner and has much narrower tires than the Empulse.  While the Zero does have to push its battery box through the air, the Empulse's radiator is quite large and the front of the bike looks to me to offer more air resistance than the front of the Zero.  When you add that to the Empulse's transmission and O-ring final drive inefficiencies (plus its greater weight), I would be surprised if the Zero does not use less power to get down the road, at the legal speeds that it is designed to operate at, than the Empulse.

[Biff]

Zero claims 43 miles @ 70 mph constant for the Zero S, 184 Wh/mile. Brammo claims 56 miles @ 70 mph constant for the Empulse R, 166 Wh/mile.

I'm confused:  Zero claims 43 miles@70 mph for the ZF6:  That's 6000Wh/43miles or 139 Wh/mile.   The ZF9 is 63 miles @ 70 mph; 142Wh/mile.
Where did you get 184 Wh/mile?

That 43miles for the ZF6 is the 70mph commuting range, which is an average of the 70mph constant speed range and the UDDS range.  For the ZF9 commuting range is 63miles.  Since Zero doesn't post their 70mph constant speed range on their website, you have to do a little math using the formulas they provide to determine what the 70mph constant speed range is. It just happens to turn out that the ZF9 70mph constant speed range is 43miles (same as the ZF6 commuting range).  Brammo lists all three ranges, UDDS, 70mph highway and Combined.  Brammo's Combined range is calculated using the same method as Zero's Commuting range and so far the reports I have read on forums like these suggest that the Combined / Commuting range is actually a very good estimate at "real world" range the bikes are getting.

-ryan

[protomech]

I heard on the news yesterday that the Honda Insight small-claims lawsuit, where the owner received a judgement of almost $10K , was tossed out by the Superior Court, due to the mileage claims following the government testing standard (or something like that).

This lawsuit?
http://www.latimes.com/business/money/la-fi-mo-honda-civic-lawsuit-20120509,0,3088344.story

As far as rolling drag between the Zero and the Empulse goes, my money is on the Zero. It is thinner and has much narrower tires than the Empulse.  While the Zero does have to push its battery box through the air, the Empulse's radiator is quite large and the front of the bike looks to me to offer more air resistance than the front of the Zero.  When you add that to the Empulse's transmission and O-ring final drive inefficiencies (plus its greater weight), I would be surprised if the Zero does not use less power to get down the road, at the legal speeds that it is designed to operate at, than the Empulse.

Yes, the Empulse should have significantly greater rolling resistance than the Zero .. or the Enertia Plus, for that matter. It uses 77 Wh/mile for the EPA UDDS vs the Zero S 69 Wh/mile. Enertia Plus is 77 Wh/mile as well .. which is a little odd. Empulse is heavier and uses bigger, softer tires.

I'm confused:  Zero claims 43 miles@70 mph for the ZF6:  That's 6000Wh/43miles or 139 Wh/mile.   The ZF9 is 63 miles @ 70 mph; 142Wh/mile.
Where did you get 184 Wh/mile?

That 43miles for the ZF6 is the 70mph commuting range, which is an average of the 70mph constant speed range and the UDDS range.  For the ZF9 commuting range is 63miles.  Since Zero doesn't post their 70mph constant speed range on their website, you have to do a little math using the formulas they provide to determine what the 70mph constant speed range is. It just happens to turn out that the ZF9 70mph constant speed range is 43miles (same as the ZF6 commuting range).  Brammo lists all three ranges, UDDS, 70mph highway and Combined.  Brammo's Combined range is calculated using the same method as Zero's Commuting range and so far the reports I have read on forums like these suggest that the Combined / Commuting range is actually a very good estimate at "real world" range the bikes are getting.

Yes, that's right.

Zero calculates highway commuting (combined) like so: combined = 2 / ( 1 / city + 1 / highway ).
You can back this out to highway = 1 / (2 / combined - 1 / city) = 1 / (2 / 63 - 1 / 114) = 43.5.
Compute efficiency as 7.9 kWh / 43.5 miles = 182 Wh/mile.

And it's fucking stupid that Zero doesn't list the pure highway range directly.

[Biff]

Zero calculates highway commuting (combined) like so: combined = 2 / ( 1 / city + 1 / highway ).
You can back this out to highway = 1 / (2 / combined - 1 / city) = 1 / (2 / 63 - 1 / 114) = 43.5.
Compute efficiency as 7.9 kWh / 43.5 miles = 182 Wh/mile.

And it's fucking stupid that Zero doesn't list the pure highway range directly.

I think the problem with listing a pure highway range is that it can be very different depending on rider weight, temperature, tire pressure, road condition, elevation changes, rider clothing, rider position, the riders ability to maintain a set speed, etc.  It is a relatively easy test for a customer to try, and then get results that are significantly different than advertized and then suspect there is something wrong with their bike.  I guess since Brammo has published their 70mph range they will find out if their customers actually achieve the advertized distance. 

Has anyone tried going 70mph sustained on a ZF9 S in a tuck from fully charged until the bike no longer sustains that speed on a flat road with no wind?

[Neal_Saiki]

I'm not sure, but I think that the ranges from Brammo and Zero are from riding on a dyno.  The dyno has a load profile that is supposed to compensate for an average wind resistance and it varies with speed.  The 70 mph distance from the dyno data is probably pretty close to reality though because neither of those motorcycles are especially aerodynamic.  The average sportbike is slightly more aerodynamic.

It also seems to agree with the ranges that people are reporting on the forums.

How aerodynamic can it get?  The human powered bicycle 1 minute speed record is 82 mph right now.  That's using around 1 horsepower (746 watts).  At that rate, a 9.3 kwh battery could go more than 1000 miles.  Those bicycles look like missiles so of course a real motorcycle couldn't be anywhere near that, but there are huge gains to be made in freeway range if ony electric motorcycles were more aerodynamic.

[Marshm]

It seems most people are using their bikes for street.  Since a dualsport bike is available, I am curious about offroad range.  On trails my average speed shows maybe 15mph, with a max of 45mph.  So from the information I read here, the slow speeds will really help range.  But I bet offroad has a whole bunch of other factors that reduce range.  Anyone try a ride on some single track or quad trails to get an idea of offroad range at the speeds listed above? 

[firepower]

I dont understand why they need to have 6 speed gear box, wouldnt a 2 or 3 speed have less fritional losses and weigh less.
2 speed gearbox would make sense low to mid, and mid to high.
most motorbike have 2 speed , fast and stopped.

[Neal_Saiki]

I dont understand why they need to have 6 speed gear box, wouldnt a 2 or 3 speed have less fritional losses and weigh less.
2 speed gearbox would make sense low to mid, and mid to high.
most motorbike have 2 speed , fast and stopped.

Yes a 6 speed gearbox is totally overkill.  2 speeds like on a Tesla car is plenty.  6 speeds is more about having fun rather than being practical.  I must admit that for the first year of riding electric motorcycles I missed the gearbox.  At first it feels weird to do nothing with your left hand/foot.  After a long while I got used to it and now I can concentrate on more important things like keeping my front wheel from sliding.  Yuck!  Of course you don't have to use all 6 speeds, but it's a lot of weight, complexity and maintenance you are paying for. 

Different strokes for different folks!