Brammo Owners Forum
Brammo Empulse Discussion => Brammo Empulse => Topic started by: FreepZ on August 02, 2013, 01:37:27 PM
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Here are some views and suggestions about shifting with the Empulse:
- The clutch is never fully disengaged.
- You will notice this when you pull the clutch while at a standstill and twist the throttle. The bike will try to move.
- My guess is that this is done to prevent the motor from over speeding, since without something to slow it down the motor will spin up to maximum RPM in a fraction of a second.
- There is a sweet spot on the throttle where the motor is neither accelerating nor decelerating the bike. This position is independent of your speed.
- You will notice that you are in the sweet spot because the bike will be coasting and it will "bounce" between accelerating and decelerating.
- You can change gears with the least amount of backlash and the greatest of ease if you do that with the throttle in that sweet spot.
- When in the sweet spot, you can shift up or down to any gear.
- Trying to match the the motor speed with the transmission is a lot harder than simply finding the sweet spot on the throttle, which doesn't change.
The sweet spot system for changing gear works well for the Empulse because (from what I can tell), the throttle position determines if the motor should speed up, slow down or coast (in the sweet spot). Unlike an ICE, the electric motor doesn't have much inertia, so the only thing that will slow down the motor (besides the load*) is the controller telling it to do so. While in the sweet spot, the transmission can grab the motor and speed it up or slow it down very quickly (since the motor is so light), and the biggest thing that will prevent that smooth transition is you telling it to go faster or slower by moving out of that sweet spot.
Note that when you power shift (i.e. shift without using the clutch), you need to bring the throttle to the sweet spot. I find that I can shift even more smoothly when I do use the clutch at the same time.
* The Load on a motor is whatever forces it's fighting against. Wind, incline, acceleration, etc.
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Yes, I'd add in a tip I learned from powershifting my BMW:
1) When I want to shift up, I hook my toe under the shifter and apply a little upward pressure.
2) I roll off the throttle slightly, toward that "sweet spot" of neither acceleration nor deceleration.
3) The transmission will easily and smoothly snick into the next highest gear, as soon as it feels the sweet spot.
I almost always use the clutch to downshift, but the same method has worked for that too.
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Great suggestions! I tried this on my way home tonight and what a difference. It makes sense, but those habits of dumping the throttle to shift on my ICE bikes carried over. Now I know better! Thanks for the great tips. I had a much smoother ride home tonight.
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I think it was BrammoBrian that posted that the Empulse will greatly reward smoothness.
Or something like that. Whatever, he's so right about it.
The bike is making me a much better rider: light, precise, smooth. And the grin to go with it. ;D