Brammo’s Wismann on Range/Speed and Fairings

Reading a great discussion over on elmoto.net about the Brammo Enertia, range, and why there is no “range to speed curve chart” for the Enertia.  The answers are provided by Brammo’s own Brian Wismann:
Quote:
Originally Posted by nathanabbott
BrammoBrian, do you know where I could find data on the range to speed curve for the Enertia? Maybe a chart or whatever you have? Otherwise, is there a way I can calculate range at a given speed with a rider who’s weight is remarkably similar to mine (190lbs)?

 

Additionally, is there an easy way to mount an aerodynamic fairing on the Enertia? Does Brammo sell one as an accessory? You’ve probably already seen this but just in case…
http://www.schultzengineering.us/chap3.htm

Thanks in advance for any info you can provide. I think i’m going to buy an Enertia this week.

Nathan,

The Enertia has been designed for a rider of your weight. Believe it or not, the average weight for an American male is 190 lbs. We have a couple of test riders that regularly commute 30 miles one way into the office that weigh 250+ lbs. Dave Schiff, who joined me on the ShockingBarack.com trip weighed around 190 lbs as well.

I don’t want you to feel like this is a “cop out”, but we don’t have this range chart you’re requesting for alot of reasons. Basically, the range of the bike is dependent on so many conditions, that it would be difficult to make it applicable to everyone’s independent situation. The other issue is getting to a common understanding of “average speed”. For instance, in true urban traffic (downtown Portland for instance), you could get over 50 miles range driving with or faster than the flow of traffic all day. This is because with the amount of starts and stops, your average speed over that ride will be quite slow. Sustained freeway driving is the worst case for an EV, because the current draw is high AND continuous, depleting the batteries at a much higher rate. In the scenario where a guy your size hops on the bike and immediately pins it at 60-65mph on the interstate or freeway, I’d estimate you’d be out of juice in about 20 miles based on testing we’ve done here, albeit with the heavier riders I was mentioning earlier. The 42 mile range that’s quoted on our website is for a driving cycle specified by the EPA that is neither this true urban cycle nor the “freeway EV destroyer cycle” I’ve described. It attempts to approximate a more average commute around a suburban area in California including both fast, sustained riding and starts and stops. I’ll make a mental note to look it up today and post the profile we’ve tested to.

This is getting long, but I really want to be clear about this, one of the most important issues for electric vehicles. Another factor in all of this is rider skill. But not just motorcycle rider skill (although that does help)… electric motorcycle riding skill. I’m sure other forum members can atest to this, but there is a certain finesse in throttle application and braking that can also have a significant impact on range. For example, when we first put Roy Richardson on our Isle of Man race bike out at the Jurby test track, he only managed 30 miles of continuous riding at race pace. The race course is 37.75 miles long, so we were stunned – how could our calculations of required energy capacity have been so far off? Luckily, we made some observations about his riding style and throttle application and instead of making huge adjustments to the bike, spent some time with Roy describing what we’d learned in testing on throttle control and maintaining momentum (i.e. staying off the brakes) through corners. Roy went out the next day with this knowledge and ran out of time at the end of the session with 44 miles logged at race pace AND better lap times. I also noticed this “phenomenon” with Dave on our Shocking Barack trip. During the first legs of the journey, Dave would be nursing the bike in (hence the famous run in with the cops in Adrian, MI: http://www.youtube.com/user/Shocking…41/Y7T4ChCg7uo) wheras I would have plenty of juice to spare. We initially chocked this up to rider weight differences, but by the end of the journey, Dave was actually out performing me on mileage on a charge! He certainly had plenty of seat time to learn the bike and coupled with the few tips I gave him, he was able to make a few minor adjustments to himself to get the most out of the bike. That’s not to say that the bike’s not easy to ride or to learn to ride, it’s just that – like anything – you’ll get the most out of it if you make yourself adaptable as well.

Regarding the fairing… Yes, you should be able to mount a small fairing like we did on this TTXGP promo bike quite awhile ago…

This is a Triumph Thruxton fairing with some minor modifications. I think the aero advantage here was small…

A larger fairing like the one you’ve referenced would be a more significant challenge, but anything is possible with fiberglass and a little creativity! It would be rad if someone made an Enertia TTR replica with their bike…

IMG_0467

Go get your Enertia so I’m not the only one with a bike on this forum! People want to hear from real customers! You won’t regret it. It’s a killer ride and now a killer deal. In fact, it’s such a good deal (now I’m really going to get myself in trouble) that you builders should just buy the bike and use the parts for your conversion AND get the 10% Federal tax credit. Ok, ok, I hope you don’t do that… I was mostly kidding.

Let me know if you’ve got any other questions.

-Brian.

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