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[Richard230]

Based upon my experience with soft saddlebags, they can really put a drag on your "fuel mileage". I went on a 1000-mile trip last summer with a set of relatively small saddlebags on my BMW and the fuel mileage dropped a good 10% compared with riding "naked". Now I don't use saddlebags unless I really need to. I try to pile stuff on my rear seat and luggage rack and only install the saddlebags if there is an overflow.   

[ZeroSinMA]

Based upon my experience with soft saddlebags, they can really put a drag on your "fuel mileage". I went on a 1000-mile trip last summer with a set of relatively small saddlebags on my BMW and the fuel mileage dropped a good 10% compared with riding "naked". Now I don't use saddlebags unless I really need to. I try to pile stuff on my rear seat and luggage rack and only install the saddlebags if there is an overflow.   

Brammo Empulse supposedly ships May 8. Specs here http://electricmotorcycleforum.com/boards/index.php?topic=2043.0

Driving Range  City: 121 miles*   (195 km)
Highway: 56 miles**    (90 km)
Combined: 77 miles***  (124 km)

*SAE City Riding Range Test Procedure for Electric Motorcycles (variable speed, 19 mph / 30km/h average)
**SAE Highway / Constant Speed Riding Range Test Procedure for Electric Motorcycles (70 mph / 113 km/h  sustained)
*** SAE Highway Commuting Cycle (.5 City weighting, .5 Highway weighting)

[ZeroSinMA]

Based upon my experience with soft saddlebags, they can really put a drag on your "fuel mileage". I went on a 1000-mile trip last summer with a set of relatively small saddlebags on my BMW and the fuel mileage dropped a good 10% compared with riding "naked". Now I don't use saddlebags unless I really need to. I try to pile stuff on my rear seat and luggage rack and only install the saddlebags if there is an overflow.   

Brammo Empulse supposedly ships May 8. Specs here http://electricmotorcycleforum.com/boards/index.php?topic=2043.0

Driving Range  City: 121 miles*   (195 km)
Highway: 56 miles**    (90 km)
Combined: 77 miles***  (124 km)

*SAE City Riding Range Test Procedure for Electric Motorcycles (variable speed, 19 mph / 30km/h average)
**SAE Highway / Constant Speed Riding Range Test Procedure for Electric Motorcycles (70 mph / 113 km/h  sustained)
*** SAE Highway Commuting Cycle (.5 City weighting, .5 Highway weighting)

The Brammo Empulse R weighs 100lbs more than the Zero S but gets 10 miles more range? Hmmmm. Maybe so if 20% of the extra weight is the gearbox and 80% of the extra is battery.

[craigq]

Brammo Empulse gets more range because it's battery pack is larger (in a kWh sense, no idea of the physical dimensions).

Brammo Empulse - 121 miles on 9.3 kWh
Zero S ZF9 - 114 miles on 7.9 kWh

So for the UDDS cycle Empulse uses 76.9 Wh/mile, S ZF9 uses 69.2 Wh/mile.

It would be interesting to know if the Empulse was tested on the UDDS using all of the transmission's gears or if it was left in one gear. Those Wh/mile figures are quite close, and the ZF9 weighs quite a bit less than the Empulse.

[ZeroSinMA]

Brammo Empulse gets more range because it's battery pack is larger (in a kWh sense, no idea of the physical dimensions).

Brammo Empulse - 121 miles on 9.3 kWh
Zero S ZF9 - 114 miles on 7.9 kWh

So for the UDDS cycle Empulse uses 76.9 Wh/mile, S ZF9 uses 69.2 Wh/mile.

It would be interesting to know if the Empulse was tested on the UDDS using all of the transmission's gears or if it was left in one gear. Those Wh/mile figures are quite close, and the ZF9 weighs quite a bit less than the Empulse.

I'll take the 11 miles lower projected range for 100 lbs less weight and greater agility and no gears to deal with. I never ride over 70MPH anyway never mind 88MPH.

[Lipo423]

I will be really surprised if the Empulse has better range than the ZF9...making a very light analysis on their recently published specs the bike is 100 pounds heavier, it has very big tires (180 rear on a 17" rim needs a lot of energy to be rolled), but on the positive side -for range- it has less drag as your riding position on the bike is very agressive "R", and around 1,4Kw more of battery capacity, we'll see...

Concerning the bike bags. Have any of you guys tried the OGIO No drag? -It is a backpack, and there are different models, here is a very good review of it.


Let's start by saying I hate backpacks for riding, they move all the time, uncomfortable, etc...but when I read the reviews, I decide to buy one (which was a difficult exercise I must say -availability in Spain-), it works pretty well though

[protomech]

Thanks for the bag link. I kind of dig that.. I have a similar profile Intel-branded bag that I picked up at a tradeshow a while back, but it's not nearly as nice and definitely is not waterproof.

Ogio also makes some nice looking tailbags. Hm.

[kingcharles]

Brammo Empulse gets more range because it's battery pack is larger (in a kWh sense, no idea of the physical dimensions).

Brammo Empulse - 121 miles on 9.3 kWh
Zero S ZF9 - 114 miles on 7.9 kWh

So for the UDDS cycle Empulse uses 76.9 Wh/mile, S ZF9 uses 69.2 Wh/mile.

It would be interesting to know if the Empulse was tested on the UDDS using all of the transmission's gears or if it was left in one gear. Those Wh/mile figures are quite close, and the ZF9 weighs quite a bit less than the Empulse.

Brammo claim the gears contribute to a longer range. But how big that contribution is they don't say.

[ZeroSinMA]

Brammo Empulse gets more range because it's battery pack is larger (in a kWh sense, no idea of the physical dimensions).

Brammo Empulse - 121 miles on 9.3 kWh
Zero S ZF9 - 114 miles on 7.9 kWh

So for the UDDS cycle Empulse uses 76.9 Wh/mile, S ZF9 uses 69.2 Wh/mile.

It would be interesting to know if the Empulse was tested on the UDDS using all of the transmission's gears or if it was left in one gear. Those Wh/mile figures are quite close, and the ZF9 weighs quite a bit less than the Empulse.

Brammo claim the gears contribute to a longer range. But how big that contribution is they don't say.

Brammo Empulse R
Battery Pack Capacity: 10.2 kWh (max)
Driving Range: City: 121 miles
Weight: 440lbs. / 200kg

Zero S ZF9
Maximum capacity: 9.0 kWh
City (EPA UDDS) 114 miles
Curb weight: 341 pounds (155 kg)

BE: 440 lbs / 10.2kWh = 43.14 kWh/lb
Zero S: 341 lbs / 9 kWh =  37.89 kWh/lb

BE has a 12% better kWh/lb ratio than Zero S but has only 6% more range, assuming range is EPA UDDS in both cases.

Maybe the gearbox reduces range?

[protomech]

Empulse weighs 100 lbs more and has heavier, probably stickier tires. IET might actually help city range a bit, since the motor won't spend as much time in the inefficient low RPM / high load regions .. but balanced against mechanical losses from the IET.

Also you should probably use the nominal capacities, not the max capacities.. and you're actually flipping the units.

Empulse R is 440 lbs / 9.31 kWh = 47.3 lbs / kWh
Zero S ZF9 is 341 lbs / 7.88 kWh = 43.3 lbs / kWh

You also want to consider rider weight, aero drag, and constant loads (headlight, control systems). I imagine the EPA dyno load has a very simple model for these parameters.

[ZeroSinMA]

Empulse weighs 100 lbs more and has heavier, probably stickier tires. IET might actually help city range a bit, since the motor won't spend as much time in the inefficient low RPM / high load regions .. but balanced against mechanical losses from the IET.

Also you should probably use the nominal capacities, not the max capacities.. and you're actually flipping the units.

Empulse R is 440 lbs / 9.31 kWh = 47.3 lbs / kWh
Zero S ZF9 is 341 lbs / 7.88 kWh = 43.3 lbs / kWh

You also want to consider rider weight, aero drag, and constant loads (headlight, control systems). I imagine the EPA dyno load has a very simple model for these parameters.

Always check my math! You are correct. But how can the Empulse have an 8% worse weight/power ratio and 6% better range? Doesn't add up. Throw in the fatter, stickier tires and the extra range over the Zero is a mystery. I didn't see EPA UDDS mentioned in the Empulse range specs. Maybe not apples and apples?

[protomech]

A very simple model for power required to maintain a certain speed is basically constant load + rolling resistance * weight * velocity + aero area * (effective air velocity) ^ 2

Energy per mile then is the integral of the power required over the course of the mile .. or assuming constant parameters, power / velocity. (watt / mph = watt-hours / mile)

Energy per mile is then constant load / velocity + rolling resistance * weight + aero area * air velocity


Here's a good calculator to start with:
http://ecomodder.com/forum/tool-aero-rolling-resistance.php

Empulse R:
620 lbs w/ rider
0.03 Crr (sticky tires)
0.65 Cd (aero fairing helps a bit)
0.7 A (rider in a bit of a tuck)
0.92 Engine efficiency (really engine + controller)
0.85 Drivetrain efficiency (IET has losses, chain > belt)
100w parasitic overhead (lights)

35 mph: 2.46 kW, 70 Wh/mile, 132 miles
45 mph: 4.02 kW, 89 Wh/mile, 104 miles
55 mph: 6.26 kW, 114 Wh/mile, 82 miles
65 mph: 9.31 kW, 143 Wh/mile, 65 miles
70 mph: 11.2 kW, 160 Wh/mile, 58 miles

Zero S:
520 lbs w/ rider
0.02 Crr (less sticky tires)
0.8 Cd
0.8 A
0.90 Engine efficiency (really varies based on speed)
0.94 Drivetrain efficiency (belt is a little worse than chain, still pretty good)
100w parasitic overhead

35 mph: 2.32 kW, 67 Wh/mile, 118 miles
45 mph: 4.21 kW, 94 Wh/mile, 84 miles
55 mph: 7.04 kW, 128 Wh/mile, 62 miles
65 mph: 11.0 kW, 170 Wh/mile, 46 miles
70 mph: 13.5 kW, 193 Wh/mile, 41 miles


Note that these numbers are just for steady state cruising, I could probably tweak the parameters a bit to match Zero's 55 mph (XU) and 70 mph (S/DS) and Brammo's 70 mph numbers. The EPA UDDS city test has a lot of stops and starts, and those will significantly penalize the heavier Empulse.

Note too that in steady state driving, even at 35 mph aerodynamic drag is fully 50% of the power used.

[ZeroSinMA]

A very simple model for power required to maintain a certain speed is basically constant load + rolling resistance * weight * velocity + aero area * (effective air velocity) ^ 2

Energy per mile then is the integral of the power required over the course of the mile .. or assuming constant parameters, power / velocity. (watt / mph = watt-hours / mile)

Energy per mile is then constant load / velocity + rolling resistance * weight + aero area * air velocity


Here's a good calculator to start with:
http://ecomodder.com/forum/tool-aero-rolling-resistance.php

Empulse R:
620 lbs w/ rider
0.03 Crr (sticky tires)
0.65 Cd (aero fairing helps a bit)
0.7 A (rider in a bit of a tuck)
0.92 Engine efficiency (really engine + controller)
0.85 Drivetrain efficiency (IET has losses, chain > belt)
100w parasitic overhead (lights)

35 mph: 2.46 kW, 70 Wh/mile, 132 miles
45 mph: 4.02 kW, 89 Wh/mile, 104 miles
55 mph: 6.26 kW, 114 Wh/mile, 82 miles
65 mph: 9.31 kW, 143 Wh/mile, 65 miles
70 mph: 11.2 kW, 160 Wh/mile, 58 miles

Zero S:
520 lbs w/ rider
0.02 Crr (less sticky tires)
0.8 Cd
0.8 A
0.90 Engine efficiency (really varies based on speed)
0.94 Drivetrain efficiency (belt is a little worse than chain, still pretty good)
100w parasitic overhead

35 mph: 2.32 kW, 67 Wh/mile, 118 miles
45 mph: 4.21 kW, 94 Wh/mile, 84 miles
55 mph: 7.04 kW, 128 Wh/mile, 62 miles
65 mph: 11.0 kW, 170 Wh/mile, 46 miles
70 mph: 13.5 kW, 193 Wh/mile, 41 miles


Note that these numbers are just for steady state cruising, I could probably tweak the parameters a bit to match Zero's 55 mph (XU) and 70 mph (S/DS) and Brammo's 70 mph numbers. The EPA UDDS city test has a lot of stops and starts, and those will significantly penalize the heavier Empulse.

Note too that in steady state driving, even at 35 mph aerodynamic drag is fully 50% of the power used.

Excellent, Protomech. Thanks.

[craigq]

A very simple model
*SNIP*

You are a great benefit to the community!

[oobflyer]

I know this is an old topic, but thought I'd check again with other owners regarding their Real World Range. When I re-read some of the posts here I can't help but wonder if I ended up with a defective bike.  There is less than 7K miles on it, it's always been babied, garaged, and charged.

Last week I needed to go to the dealership, which is exactly 66 miles from my house. I rode there on backroads, never exceeding 35 MPH, in ECO mode. The ride took over two hours and I got there with one bar left on the gauge (6.6 miles/bar). This is typical of my experience since I got the bike, but when I see that some people are riding on the freeway for similar distances and make it with the fuel gauge at 1/2 full (5 or 6 bars) it just doesn't make sense to me.

My bike will be out of warranty in one month, so depending on the responses I get I might ask that it be checked again (download the bike logs, etc.).

If folks are making 50 mile trips on 5 bars - that's 10 miles/bar.  Is that what I should be expecting?

Thanks