"commuting" model?

[badamsfx]

My initial two cents:

With a range of 100 miles I could possibly make my sixty mile commute on the Empulse but that bent over racing position would kill me. Hopefully they'll have a more upright variation for those of us that won't regularly be going 100 mph on it.   

Anyone know how uphill grades affect range? I go over two big ones in my commute. I would plug in at work for the trip home of course.

I'm also curious how really quiet these bikes are. I am a lane splitter and a little bit of noise lets drivers know that I'm approaching. If electric bikes are truly silent then I might have to strap on some sort of noise maker.

One last question. When will we get to the age of in-hub motors? I dearly love my V-Strom but maintaining the chain each week is a pain in the butt. I'm currently considering a shaft drive bike and might even pick that over the Empulse just because I'm sick of dealing with chains. However I'm sure I'll be sold on the Empulse as soon as I sit on one!

-b-

[Phantom]

...but that bent over racing position would kill me. Hopefully they'll have a more upright variation for those of us that won't regularly be going 100 mph on it.   

Yes, there is a plan for an upright riding posture.

Anyone know how uphill grades affect range?

Yes, hills do affect range, but you can coast going downhill to preserve your charge. In my specific commute at a 100% charge, I use 26% to get to work and 34% to get home, assuming I that do not make other stops along the way. It would seem that the Empulse should have no problem based on your commuting distance and the ability to charge at work.

If electric bikes are truly silent then I might have to strap on some sort of noise maker.

The Enertia can be close to silent if you are rolling up to a stop. You will be merging with people driving while on their cells phone, listening to loud music in the car, possible texting (and some all at the same time). I know an owner of an ICE motorcycle that has a a foghorn outfitted on his bike for safety so he can be heard when we wants to be heard.

When will we get to the age of in-hub motors?

They are available now if you build a custom bike, but not from Brammo.

[Brammofan]

Phantom really answered most of the questions but I wanted to expand on the "in hub motor" issue.

From what I understand, an in hub motor represents "unsprung weight" which is weight not handled by the bike's suspension.  This can lead to some instability on bumpy roads among other problems, depending on the weight of the motor. 

I know, they sounded like a good idea when I first heard about them, and they may work for a smaller bike, such as a scooter, but most of what I've heard and read says they aren't particularly appropriate for a large motorcycle.

[webman]

Phantom really answered most of the questions but I wanted to expand on the "in hub motor" issue.

From what I understand, an in hub motor represents "unsprung weight" which is weight not handled by the bike's suspension.  This can lead to some instability on bumpy roads among other problems, depending on the weight of the motor. 

I know, they sounded like a good idea when I first heard about them, and they may work for a smaller bike, such as a scooter, but most of what I've heard and read says they aren't particularly appropriate for a large motorcycle.

Brammofan's right about this; unsprung weight is the worst kind of weight for motorcycles, as it slows the steering, particularly if it's at the front wheel.  It also makes it harder for the suspension to react to bumps, etc.  This is why racers look at wheels, tires, and brake assemblies as the first place to make weight reductions in their machines.  Buell (r.i.p.) used a perimeter brake on the front of their bikes, which allowed them to run a radically lightened front wheel on their sportbikes; I can say that it really seemed to work, having ridden a couple of their bikes before.

Scooters get away with swingarm-mounted engines largely because they're not generally used at higher speeds, where the unsprung weight becomes a greater liability.

I hope this helps clarify things. 

the webman

p.s:  I'd love to see brammo adopt Buell's belt-drive, personally.  I'd love to avoid chain-cleaning, too!

[Brammofan]

p.s:  I'd love to see brammo adopt Buell's belt-drive, personally.  I'd love to avoid chain-cleaning, too!

I'm sure there's some well-thought-out reasons that compels Brammo to stick with chain drive, but I agree with you on this.  Just think how much quieter it would be. And maybe that's one reason they chose chains.

[Phantom]

I'm sure there's some well-thought-out reasons that compels Brammo to stick with chain drive,...

Here is a post from Brian from another forum on the subject:

Ah... the chain vs. belt discussion. Oh boy. Here's how this usually goes...

Lookey Lou: Aren't electric vehicles dangerous because they're so quiet? I heard that blind people are being run over left and right by them.

Enertia Owner: They can be, although this bike makes a fair amount of noise from the whine of the motor to the chain noise.

Lookey Lou: Chain Drive!? Why don't you use a belt drive? Then it could be even quieter!

Enertia Owner: But... you just said being quiet was dangerous...

Lookey Lou (not listening at this point): ...AND put a speaker on the bike to play Harley sounds!

Enertia Owner: WOW!... great idea... thanks... gotta run. Vvvvvrrrrrrrrrrr....


Our decisison to use a chain final drive was based primarily on the following:

1. Simplicity
2. Efficiency
3. Cost

1. Simplicity - The chain is a simple, robust, and proven technology that is well understood as a mechanical and power transfer device. Everything from lubrication schedules, tooth profiles, and material types have been tested and well documented to the benefit of all engineers. A chain also has at least one mechanical advantage over a belt - it can be broken at a "master link" for installation and removable. A belt is continuous, and so requires a break in some other mechanical component, usually the swingarm, to be installed or removed. This has a dramatic impact on #1 and #3. A chain can also accomodate a certain amount of slack and stretch, which occurs on the Enertia due to the fact that our primary drive sprocket on the motor and the pivot point for the rear suspension are not concentric due to packaging constraints. In this situation with a belt drive, we would require an additional tensioner pulley to keep the belt under appropriate tension throughout the range of suspension movement, again adding complexity and cost to the system.

2. Efficiency - Depending on who you talk to, belts are either slightly less efficient or the same as a chain drive, which is in the upper 90% range for efficiency. On the Enertia, it is important to us that we focus on using the battery power as efficiently as possible so as to avoid requiring the customer to pay for more battery than is actually needed. We choose to go with what the group believed was the known most efficient final drive available.

3. Cost - Partly because chains are so ubiquitous, their cost is also very low compared to a belt. If the Enertia did have a belt drive, it would have to be a custom belt, tooled specifically for this application as it would need to be very narrow to meet our packaging constraints. We did explore this option and determined that a belt would be about 4X the cost of an equivalent chain. And that's just for the belt. The belt also requires more complete coverage around it to block small rocks, which can shread the belt, adding complex injection molded plastic covering parts to the assembly - as you can see on any Buell motorcycle. I mentioned the addition of a tensioner pulley, but there's also the additional cost of the sprockets or drive pulleys themselves. These are thicker, more complex assemblies, often with edge guards to keep the belt aligned, than a comparable chain sprocket, which of course also adds cost.

I'm sure there are other reasons I can't think of right now, but this gives you a general idea of our thought process. The huge benefit to belt drive is the lack of required maintenance, which could be beneficial when the batteries get to the point that an owner can log several hundred miles over the course of a weekend. At that point, the long term maintenance cost savings may outweigh the additional up front cost to the customer, but I will say this - VERY few consumers today look at total cost of ownership when considering a purchase, which drive many to the cheapest rather than the best solution. How much are you willing to pay additional for belt drive? If there were a chain drive Enertia available for $7995 and a belt drive version available for $8495, which would you be compelled to purchase? This is the question we must continually ask ourselves to ensure we're providing features with the best value to our customers. And I'm definitely not saying that we always get it right... but we do always ask ourselves the question.

[webman]

Thanks for posting this.  None of the items mentioned are surprises, as I know that Buell went through a tremendous effort to get their idler pulley in exactly the right place.  The other issues are also known, valid points.

I just hate dealing with chains.  And yes, I would probably pay the extra cost for the belt-drive option.  I'm sure I'm in the minority on this, though.

the webman

[badamsfx]

Wow, thanks you guys for the thorough discussion. While I would prefer a belt drive now I have a better understanding of the added complexity. I suspect not enough people would be willing to pay hundreds extra to get one to make it worth Brammo's while.

Bummer also about in-hub motors being impractical. They look so cool on those pie-in-the-sky concept drawings we see every once in a while. Would they be practical in a car since you could have power steering and balance becomes less of an issue? I remember seeing an actual prototype that had four hub motors.

I'm sure I will love my Empulse chain and all when I finally get one. Glad to know that an "upright" model is in the works.

-b-

[HighlanderMWC]

Thanks for posting this.  None of the items mentioned are surprises, as I know that Buell went through a tremendous effort to get their idler pulley in exactly the right place.  The other issues are also known, valid points.

I just hate dealing with chains.  And yes, I would probably pay the extra cost for the belt-drive option.  I'm sure I'm in the minority on this, though.

the webman

I just lubed the chain for the 17th time...I would definitely consider paying extra for a belt, especially if the range hit weren't very high.

[Kelly Olsen]

 I vote for the belt even at a higher cost. $500 more? I'd still pay for it, easy decision for this consumer.

[ColoBrammo]

I think the above article re: belts is very lucid, but I have to disagree with the mechanical complexity arguement against the belt drive,  especially on an electric bike.

With a relatively small electric motor (compared to ICE), I would think it would be rather straight forward to design the frame/swingarm AROUND the motor such that the swing arm pivot point is concentric with the axel of the motor- this completely eliminates the need for an idler pully to keep tension.  Specifically, it appears the Enertia frame would need to be wider to accomodate this, but as it's a narrow bike to begin with, I don't think this would really be that objectionable.  Comments?

As far as additional plastics to protect the belt- huh?  Plastic is pretty cheap- yes, we need to protect the belt more than a chain, but doesn't need to be a big complicated shield.

As with all things, there are economies of scale- Brammo has to fight this hard right now.  If they were shipping 50000 bikes/year, their manufacturing costs would be far lower and custom parts (such as belts) would cost far far less, in fact, they would probably be at parity with "stock" parts.

I think the Enertia in particular is screaming to have a belt drive. 

[Phantom]

Specifically, it appears the Enertia frame would need to be wider to accomodate this, but as it's a narrow bike to begin with, I don't think this would really be that objectionable.  Comments?

My point-of-reference is as a finance/cost accounting guy and not as an engineer. Safety is a big concern. I am guessing Brammo would need to re-work the frame, develop a new swing arm, require new tooling for an injected-molded, plastic protective shield for the belt and use a belt drive kit at a minimum. The material cost and cost of time/labor/overhead may not be justified yet based on the exisiting market.

I do not think that Brammo has economies of scale right now, but hopefully soon.

[Kelly Olsen]

I think the Enertia in particular is screaming to have a belt drive.

I just love that colorful turn of the phrase and fully agree with the point!

But we do now have two of these belt threads going under two different titles. Anyway to combine?

[Brammofan]

But we do now have two of these belt threads going under two different titles. Anyway to combine?

There is a way to combine, but since there were other issues discussed in this thread, I think I'll just include a link to the other one:
Carbon Fiber Belt Drive Instead of Chain?

[Kelly Olsen]

...but that bent over racing position would kill me. Hopefully they'll have a more upright variation for those of us that won't regularly be going 100 mph on it.    

Yes, there is a plan for an upright riding posture.

I missed this comment before. One of the reasons I still would get an Enertia and hope they make an Enertia model that will have the same battery packs and liquid cooled motor as the Empulse is simply because of the riding position.

Because of surgery on my neck years ago which put a piece of my hip bone in my neck bone with four titanium screws, I can't be in any position in any length of time other than up right. Plus, I just like the heads up view of being able to see what is going on.

I can't see how a upright position could be attained from the way the Empulse is designed, but that is probably just because of my limited imagination and knowledge of bike design.

But I'd be delighted to learn how this could be achieved. If it can be, then I'm there for a 8.0 Empulse.