Monthly Archives: May 2012

The Brammo Empulse Arrives…Finally

If you’ve read any of my posts on my Enertia, you know I love the bike. Of the few electric motorcycles out there, it was the absolute best bike for me. However, I knew it was far from my dream electric motorcycle. Brammo had to compromise too much in their quest to make it reasonably affordable and viable for urban transportation. To that end, it was a great success. But for the enthusiast that wants to carve some corners on their commute, there were a few shortcomings.

Specifically, the Enertia didn’t meet my needs as a rider because:

  • Cannot maintain highway speeds due to overheating.
  • 40 mile range means I can’t make extra stops on the commute.
  • Non-adjustable and over-sprung suspension.
  • Body position is poor for aggressive riding.

Some of those shortcomings could have been mitigated through some inspired modding, but deep down I knew I wouldn’t be on the bike forever. Consequently, mine’s still bone stock.

An [almost] No Compromises Electric Motorcycle

Brammo has touted the Empulse as a no-compromises electric motorcycle for the enthusiast. They’re absolutely right…almost. You have to compromise somewhere, and in this case it was price. But that couldn’t be avoided. Bicyclists have a truism that sums this up perfectly.

“Cheap, light, and strong. Pick two.” – Wise Bicyclist

With the Empulse, Brammo went all in. They addressed all of the shortcomings with the Enertia and delivered a very serious motorcycle. Sure it’s not going to out-handle or out-perform an ICE motorcycle that costs less than 50% of the Empulse, but that’s not really the point of riding an electric motorcycle is it? The point is: It’s an electric motorcycle that should be about as fun as an SV 650 with the brakes and suspension of a serious middleweight sportbike.

Liquid-Cooled Motor

Even though there are no little explosions going off inside the motor, it still gets hot. This one surprised me when I got my Enertia, because I thought it was a low-friction, brushless motor. Well electric drivetrains are still lossy systems and that loss manifests itself through heat. The Enertia has an electric fan that helps, but it’s no match for highways speeds. The Enertia goes into a thermal cutback mode well before its battery is depleted when driven at a sustained 70 mph.

The Empulse tackles this problem by water-cooling the motor. There are plenty of high-end EV motors doing this now, but I never suspected to see one on a production electric motorcycle any time soon. They put a pretty large radiator on there too.

Notice the coolant lines running into and out of the motor? I wonder if there’s a separate electric water pump or if they somehow use the power from the motor?

A Proper Transmission

If you look at the motor in the picture above, you can also see another great feature: there’s a shifter! When Brammo delayed the launch of the Empulse, they stated that they wanted to include some critical new technology. They were already working with a 6-speed transmission with the Engage, and so the folks over at http://brammoforum.com knew straightaway that the new IET (integrated electronic transmission) was going into the Empulse. The transmission is a multiplate transmission complete with oil just like a standard motorcycle transmission. I’m sure the similarities stop there.

I, for one, applaud Brammo on this move. Stunning. As Brian Wismann so perfectly stated in this video, Brammo has put a critical tool back into the hands of the rider. While I’m no expert on electric drivetrains, I think this will be critical for efficiency. It’s common knowledge that 100% of the torque of an electric motor is available at 0 RPM and that it drops off a cliff at the top end. Going to a two or three speed transmission would have solved the top-end problem, and so I was a little perplexed. I now suspect that they went a 6-speed to help the bottom end without relying solely on battery-destroying torque. Sure that torque’s available, but using it in an inefficient gear means that the motor is going to draw a tremendous amount of current. But like I said, I’m no electrical/automotive engineer.

And in a dramatic turn of events, they offer regenerative braking! Well, sort off. On a motorcycle, a huge percentage of your braking power comes from the front wheel. On a v-twin race bike, I don’t even use the rear brake because the engine braking alone is about all the rear end can handle without losing traction. Realizing this, Brammo has added a sort of regen-engine braking. I can only speculate about their motor control algorithm, but conceivable it might be sophisticated enough to deliver just the proper amount of regenerative resistance based on wheel speed, gear, and throttle position.

Level 2 Charging: 3.5 hrs from Zero to Full

Craig Bramscher and Brian Wismann have both explained several times thats they abandoned the lower-capacity battery packs and decided on one single option due to overwhelming pre-order demand for the 10 kWH packs. They settled in on a 9.3 kWH pack in the final configuration of the Empulse. It’s what happened next that really surprised me. They included support for level two charging, and not with some supplementary part that you keep at home. They put the Level 2 charger on the bike.

Now the only downside of this is that they don’t have a Level 1 cord on the bike. If this is anything like the Volt, then a Level 1 charge will likely be done with a separate adapter. That’s going to be a bit of a problem for me. I plan to steal 120 V power while at school and charge at home overnight on 120 V. Where to I keep the adapter? I’ll probably be fine at work since we have five Level 2 chargers…but I have to beat three out of the seven Nissan Leafs into the office. Great. There’s gonna be a geek slap fight in the parking lot.

They Added Proper Motorcycle Parts

The Empulse R comes with fully adjustable suspension via a Marzocchi fork and a Sachs shock. While I doubt that fully adjustable includes all four “knobs” for high/low-speed compression/rebound dampening, I’m sure that it’s got at least preload, compression, and rebound adjustments. And that’s plenty good for the most agressive street riding. Heck, most expert amateur racers and a lot of privateers can get away with a simple Penke 3-way on the rear and a re-valved stock fork.

They’ve also included some proper sportbike wheels on the Empulse R. The Enertia has really narrow, custom wheels with a direct mount sprocket in the rear. The Empulse R has a 17″ wheelset from Marchesini with a very respectable 5.5″ rear wheel. And, I’m not certain, but that rear hub looks pretty large. I suspect they’ve moved to a cush drive which will really help smooth out some of the drivetrain noise and vibration that you get on the Enertia.

You can really tell that they’ve been doing some racing too. They’ve included mounts for rearstand spools on the swingarm as well as perfectly placed threads for frame sliders on the frame. Even the big Japanese manufacturers tend to screw up mounting points for frame sliders. And the poor street riders end up getting kits that relocate the frame sliders awkwardly so that they fit through vents on the bodywork without cutting. There’s also plenty of room around the tank to put clip-ons under the top triple clamp, which was pretty much impossible on the Enertia. They also have proper foldable footpegs that I plan to promptly replace with some rearsets. I hope I can fab something to work out easily. Maybe they have some Empulse RR parts to spare. O_o

Anyone for a Two-Up Ride?

Finally, you can offer friends the experience of riding an electric motorcycle without having to trust your bike in their grubby little hands. I’ve already offered a ride to a buddy at work, and he promptly rejected me. I don’t know what his problem was. Two of my fastest laps around Jennings GP were on the back of Jason Pridmore’s GSXR. It was definitely special…and not that way.

In all seriousness though, this is one really nice looking tail section. The subframe is so thin and minimal. Razor edge tails have been trendy with sportbikes lately, but they tend too come out looking like sectioned serrated knives. The Empulse’s tail looks like a katana (the sword, not your grandma’s Suzuki). The original Empulse prototype had a misplaced tail that didn’t fit in too well. Plus it still had that long, flat design found in the Enertia. That seat style is perfect for the Enertia, because it helps to accommodate differently sized riders. The Empulse has a proper, low seat at an angle that is going to feel much better when the bike is slung over in a corner. I can’t wait!

The only thing I’m a little apprehensive about is the swingarm. It’s hard to tell from the photos, but it looks a little flimsy. Part of that is probably an optical illusion since it’s tubular. However, the pivot looks a little narrow and might suffer from some twisting. It’s also interesting that the shock is direct mount and doesn’t use a dogbone linkage to control the rate. At least the pivot seems to be pretty close to the chainline which should help with squat coming out of corners. The lower arm in the swingarm looks like it will probably be close to flat when under power too, which is apparently critical for traction when driving out of a corner. Not sure that traction’s going to be a big issues with the R though. Maybe the RR. Anyhow, the comments on the swingarm are really pretty superfluous and shouldn’t affect street riding in the least.

About that Compromise

Similar to the Enertia’s release, they’re producing the first thousand or so Empulses as the R model only. I get the impression that it’s a limited edition model, but I’m not 100% certain.

Empulse Base Model – $17k
Empulse R Model – $19k

The Empulse R has the following advantages over the regular Empulse:

  • Marchessini wheels
  • Fully Adjustable Suspension
  • Carbon fiber bodywork parts
  • And a 2012 delivery date

Personally I’m excited about all of the above R extras, save for the pretty carbon fiber parts. Hopefully the wheels are nice and light, since losing unsprung weight it critical for handling, acceleration, and braking.

Overall the R package seems like a good deal. High-end sportbikes like Aprilia, Ducati, and MV Augusta do the same thing with their racier models and often charge way more. However, you have to consider that those other manufacturers also tend to offer better brakes, exhausts, racing ECUs, etc. Personally, I like the Japanese model of just offering one version and making it as nice as possible. The Japanese can get away with that due to their economy of scale.

$19k was a bit of a shocker for me, but the way I look at it, I’ve been saving for this motorcycle since October 2010 when I pre-ordered mine. The only sad part is that I plan on owning it until it depreciates to near zero. I typically buy used bikes and only lose about 20% of their value to depreciation when I sell them. Who know what the secondhand market for electric motorcycles is going to look like. Anyone interested in a well-kept Brammo Enertia?