Sunday, October 26, 2008

The Yuba Mundo BMC Forsen two wheel drive electric bike!

One of the fun things about owning a bike shop, especially an electric one, is getting to try out fun and crazy new things.

We recently received a batch of new BMC motors, dubbed variously "600W" or "version 2" (V2). They are purported to be for higher speed use.

We decided to set up the BMC motor on the Yuba Mundo as a rear wheel drive, and the Mundo already has a Forsen 1000W/36V motor on the front. Why not? An all wheel drive bicycle with about 1800 watts of power. Somehow that seems appropriate for the Yuba, which can carry over 400lbs of cargo.

Pictures are below. Brief details:
- Yuba Mundo, a longtail cargo bike that is rock solid for carrying kids, gear, groceries, whatever
- Two LiFEPO4 10Ah batteries capable of about 40-50A output
- Front Forsen 36V 1000W hub motor. It is a high speed (up to 40 mph on the stand), low(ish) torque motor
- Rear BMC V2 600W hub motor. It is also a high speed (up to 30 mph on the stand), medium torque motor
- Right twist throttle pointing away from the Shimano twist shifter
- Left thumb throttle
- Lots of fun

The Yuba's gear range is not super wide, so by pedaling alone, the top speed is around 17 mph. However, this bike will easily accelerate to 27 mph with no pedaling, using the two motors. It sucks down some batteries, however - at 25 mph, it draws about 22 Amps, which equates to about 1000W continuous. With both motors, this bike will accelerate up hill, fast.

One more note before the pictures - everything here is only temporary, so there was no attempt made to make it aesthetically pleasing. On the bike configurations we ride every day, and the configurations for our customers, we work harder on the aesthetics.

Yuba Mundo with two motors


Front picture of yuba with Forsen motor

Kids riding on the Yuba Mundo




I'll just close with the thought that the Yuba makes a great bike for an electric setup like this - because it can haul so much weight, mounting a bunch of batteries on there is of no concern. The longer wheelbase makes it very stable even with a big load. And, the baloon tires with steel frame take up shocks in the road pretty well.

Morgan

Friday, October 24, 2008

New retail showroom coming!

Cycle 9 is coming to Carrboro! We've signed on the dotted line, paid lots of money, and gambled that Carrboro is the right place to be for a store like ours.

Starting about December 1st, our new location will be on 601 West Main Street, where the hardware store used to be. We'll be taking half of that building for Cycle 9. This is right next to the tall red brick condominium, up the street from the Gym and print shop. Not too far from our friends at Johnny's, either.

We'll post a picture here soon.

We have lots of other news and writing to post here, which is coming soon.

Please stay tuned for a Grand Opening announcement.

Wednesday, October 8, 2008

Batteries are the crux!

Anyone who has had experience with electric vehicles will come to find out that the energy storage device (usually battery) is the crux of the vehicle. On an electric bicycle, the battery has the biggest effect on the weight and performance of the vehicle.


Here are some battery types commonly used on electric bikes:

-
Sealed lead acid (SLA)
- these have been around for a long time. They are reliable, but they are very heavy, and they can only handle about 200 charge/discharge cycles for typical electric vehicle (EV) use. A typical 36-volt SLA pack weighs in at almost 40 pounds. And to make them last, it is necessary to treat them very well, by always (always!) charging them immediately after use, and never (never!) running them down too low. We try to encourage customers to look at other solutions than SLA, because they will end up having to be replaced every 1-3 years, and so in the long run, they cost more. But for someone just starting out with an electric bike, they are a good option, just to see how the ebike works out, since they represent a low investment threshold (typically $100 or so for a 36 volt lead acid pack).

-
Nickel cadmium (Nicad)
- these have also been around for quite a while. These are substantially lighter (a little more than 60%) than lead acids, and are well suited for electric bike use. They handle high discharge rates reasonably well, they can be discharged all the way without damage (in fact, it is good for them on occasion), they handle low temperatures, they don't need complicated battery management circuitry, and they often last up to 800 charge/discharge cycles. They cost 2-3x more than lead acid, but they last 3-4x longer, meaning that over the long haul, they are a better value. Their main downside is that they contain Cadmium, a toxic metal, so they must be recycled properly after they finally die.

-
Nickel metal hydride (NiMH)
- these are also a nice chemistry, which are a bit lighter than Nicad for comparable energy storage. They also handle high currents reasonably well, and do not need fancy electronic battery management circuitry. However, NiMH does not like to be fully discharged - if done so repeatedly, they will not live as long. In our experience for ebike use, the Nicads seem to last longer. Also, NiMH is quite expensive right now.

-
Lithium Ion (Li-Ion)
- there are actually several types of lithium ion battery. The three most common chemistries are lithium cobalt oxide, lithium manganese, and lithium iron phosphate. Any one of these can be labelled "lithium ion," but they have very different properties. Lithium cobalt oxide is very lightweight (high power density), but has a big problem - it likes to catch on fire if short circuited or abused. So few if any people use these for electric vehicles.
Lithium manganese (Li-Mn)
is much safer, but weighs a bit more. It lasts about 500 charge/discharge cycles. This is a very common battery chemistry for electric bikes, and is quite reliable and safe in practice. It provides a nice balance of cost/weight/safety. Several of our kits, such as the eZee hub motor kit and our new Cycle9/Txed/8fun kit (watch our blog for details) include a Li-Mn battery.

- Lithium Iron Phosphate (LiFePO4) - these are the latest/greatest (and much hyped) electric vehicle battery solution. In theory, these cells will last upwards of 2,000 charge/discharge cycles. They are extremely stable/safe, and somewhat tolerant of abuse. They can handle high discharge rates, though that depends on who makes them. They are about the same weight as Lithium Manganese, i.e. about 10 lbs for a 36V/10Ah pack (common electric bike size).

We are excited about LiFePO4 technology, but we have become a bit more cautious about it. We've found that these batteries vary widely in their quality and their ability to output currents sufficient for electric bicycle use,
depending on who makes them
. We've had long-term (1 year) experience with packs from several suppliers, with greatly varying results. This picture shows what we've had to do to fix packs for customers, supplied by one Chinese supplier:
IMG_0007

This situation was no fun for us (we spent a lot of time replacing cells and reprogramming the battery management system, BMS) - and it was no fun for the customer who had to wait while we did that.

There are a few reputable Chinese LiFEPO4 suppliers, and we are continuing to examine options for a Chinese-supplied LiFEPO4 pack, because they are less expensive. We have 3 packs
on the way
here from one supplier who claims to have rigorous quality assurance procedures in place. If that testing goes well, we will begin selling them as a "beta test" situation, at a reduced price (
). Those are cylinder-cell based, 10Ah 36V LiFEPO4, with an external balancing charger, and 6 month warranty provided by the same company that provides the BMC hub motors. The good thing about these is that warranty/support is US based. The other good thing is that the packs are long and narrow (3.25"x3.25"x13.5"), making them a good candidate for attaching to a bike downtube or seat tube by your favorite attachment mechanism (duct tape works, though is not pretty). One downside is that they have very thin discharge wires. I am promised by the supplier that these hold up over time in the field, but I am thinking I may replace them with larger gauge wiring at some point.
IMG_0013IMG_0012

My own opinion on those is that they should work reasonably well for bike setups with discharge rates below 20A. While they are rated up to 30A, past experience tells me it is never good to push the limits on such a rating, or cell failures are a likely result. One solution to this problem for higher-current needs is to double up on capacity, i.e. get a higher capacity battery (20Ah instead of 10Ah), which can handle higher discharges. Another is to put two batteries in parallel, so each one is providing approximately half the current. I use that solution on my bike, with two 10Ah (36V) LiFEPO4 packs in parallel to provide up to 35A for my current-hungry controller. Before, I was using just a single 10Ah pack and it was clearly unhappy with 35A - I ended up replacing a failed cell. But now that I have them in parallel, things have stabilized.

So, all that said, the most field-proven LiFEPO4 batteries that can handle high currents and really do live up to the hype in most cases are Taiwanese-made cells (and US made cells, if you can get them).

However, the USA and Taiwanese-made LiFEPO4 packs (like A123 systems) tend to induce a bit of sticker shock. But, for those who can overcome that shock, they are worth it in the long haul.

One Taiwanese supplier of LiFEPO4 is Phisiang. We've carried some of their packs in the past, like the one pictured here:
Phisiang (PHET) LiFEPO4 battery


These are nice packs, and have been very reliable. However, they have two issues:

- They are low capacity only, 7Ah for the 36V version. That's a pretty small pack. Also, the discharge rate is limited to around 20A. For such an expensive battery, it is unfortunate that the packs can't handle higher currents. PHET makes larger packs, but they are unwieldy and not cost effective

- The responsiveness of the company to warranty issues (we've only had one) is not the best. Problems get resolved, but slowly and with big shipping expenses overseas.

We can still get these batteries for customers who request them, but we aren't stocking these anymore.

We looked around for a suitable replacement that has a similar quality, but higher capacity and better support. The result of that is we are now a LifeBatt distributor. This is a premium LiFEPO4 battery that is guaranteed for 3 years, and can handle the high currents required for electric bike use.

This battery features cells that can handle up to around 100 amps (10C rates), with a sophisticated onboard battery management system (BMS) for cell balancing and monitoring. There is a serial port on the battery for diagnostics, and a low-voltage-cutoff circuit can (should) be added for electric vehicles where there is not a low voltage cutoff in the controller.

More pricing and information will be available soon, but we've pictured below the 36V 10Ah pack, which is $750 plus shipping, from Taiwan.


Retailpackprice.doc-2


We'd love to stop there and be done with it - the LifeBatt packs look to be really nice over the long haul. However, there are still two things to consider. First, the shape and size of the packs is not optimal for many electric vehicle configurations. Second, one of the owners of the LifeBatt company has had conflicts on public forums with various members of the electric bike community. We won't take sides in that, but we will say that we understand that there are some people who don't want to buy a LifeBatt for that reason.

So we are now on our way to another option. We will be building up custom packs for customers on request, using the same high quality Taiwanese made cells that go into the LifeBatt. We cannot claim that these are for electric bike use, because there are various patent battles over who owns the rights to LiFEPO4, and who can use them on e-bikes (silly IMHO, but that's for another blog post). But we can say that we would have difficulty preventing a customer from putting one of these on his or her bike (especially if that customer doesn't tell us about it). And we can also say that we are planning a configuration that is more amenable to strapping these packs to various kinds of metallic tubing that comes in, say, 3/4"-2" shapes/sizes. And our price will be competitive with other packs made from similar high quality cells. Interested? We are about to begin the first batch, and it will be limited to about 4 packs total, two of which are already spoken for. Please contact us if you want to know more.

Now, finally - in the meantime, we also continue to stock other options, such as Nicads that provide a viable and lower cost alternative to LiFEPO4. We have one Nicad pack that is triangular, and fits right into a triangular bag in the main triangle of the bike frame. That's a pretty nice configuration, for a much lower expense.

We will be announcing our new web-store soon, and all our battery options will be listed there. Or, you can


Morgan





Sunday, October 5, 2008

BMC Hub motors cont'd

We've had a great time testing the BMC V1 (alternatively called "Puma" and/or "400W"). It is a nice little motor that has great torque for its size, it is quiet, and so far, very reliable. We have one of these left, a wheel with a 2-cross black spoke pattern, pictured below. This is the last one we'll have for sale at our beta-test price of $550 (includes controller, thumb throttle, motor/wheel). After we get feedback from our testers, we'll be re-offering these at their market price, which will be higher.

If you want to be our final beta tester, you can use the paypal button below, or contact us. Note that with a beta test, you need to realize that you will be getting a reduced price, in return for your patience in case there are unanticipated problems (e.g. if spokes break, wheel comes out of true, etc). We will work with you to fix any problems if they occur. We also ask that after you use it for 1-2 months, you give us feedback.








Options






Thursday, October 2, 2008

News from the front in the war on bike purism

We've had a lot going on this week, with moving our store to a smaller, temporary space while we sort out our permanent retail showroom. Nonetheless, the wheels of my mind are always turning, and here are a few resulting random thoughts:

-----
On the financial situation in the US. This is the big, big news. I can feel it in the air - everyone senses change is coming. Yes it is. The current blow-up in the big banks was not at all surprising to me. I've been reading this great site, itulip.com, for several years now. Eric Jantzen, its founder takes the long view based on history about our present situation, which he predicted quite accurately a few years ago. It is a large and complex problem that boils down to one simple thing: the USA has way too much debt. It is not just government, it is all of us. We are in hawk up to our ears as a nation. And our creditors are nations like China, Japan, and Saudi Arabia. Our continued spending spree is dependent upon them continuing to provide us an ever expanding credit line. Let's compare this to personal finances. One can get ever bigger credit lines and get further in further in debt - to a point. But when the creditors decide that the debts are too big to pay, they stop lending new money. What would (will) happen if (when) these countries decide to stop funding our profligate spending as a country? To sum up: ouch. A big change in the way most of us live, at least until we figure out how to get our manufacturing businesses re-started and re-build an economy based on true value, not just Finance, Insurance, and Real Estate (FIRE, a term coined by Mr. Jantzen).

What does this have to do with bikes? Two things. First, a big portion of our debt as a nation are the > $500 billion per year we spend importing oil. What do we provide in return for those 4.8 billion barrels of oil we import per year? Create paper (or electronic) money. Money that can be printed, or at least created out of thin air as new treasury issues (i.e. debt). We are racking up the mother of all debts - debts that will be very hard to repay with anything of concrete value, unless we sell off all our assets to foreigners. The best way to reduce this debt, here and now, is for all of us to use less oil. Based on my own personal experience, electric bikes are the best available option, here and now, not some pie in the sky electric car that may or may not exist in the future at a price that may or may not be affordable to most of us.

But second, we as a business feel a responsibility to our community. We think that at least some of our products need to be produced locally. It is a long road from where we are now to that future, because in the past years, it's been pretty darn hard to compete with the Chinese and other countries on labor costs. But that is changing, slowly. Shipping costs are rising, while the dollar is sinking (see the stuff about our debt above, for an explanation of why). This means that as currencies like the Chinese Yuan rise against the dollar, imported products will get a lot more expensive. This is likely to re-balance the equation back towards making it favorable to produce at least some products at home. We are already starting in small ways - we build our own BMC wheels up in house, and we are designing a new DC/DC converter to power bike lights, stereos, coolers, etc directly from the main bike battery. That, too, will be produced locally. Those are small but important steps, providing local employment, and a tiny bit of insulation against drastic changes in world trade as various currencies re-balance.

-------

The eZee 26" kits are back in stock. These are still one of our favorite kits for upgrading a bike to electric - light weight and reliable. Also, easy to install.

-------

We've had a lot of inquiries about the BMC hub motors. We hand-build each wheel, so we'll be working hard to keep up with the interest.

Our next batch will be the new BMC V2 motors, which are capable of higher power and speed. Nominally rated at 600W, the new V2 motors have heavier wiring and internals to allow more extreme usage. They are capable of peak power of up to 1200W or so. We'll post more here as we get these in our hands and on our bikes for testing. We also have a V3 wheel (1000W) for testing. That wheel is supposed to be very, very fast.

-------

Well, the title of this entry mentions bike purism. I recently saw an article about the explosion of electric bicycles now available in the market. Some of the commenters wrote in with a negative attitude about electric bikes. The objections raised are the same ones I've been hearing since my first e-bike in 1994: why do you need power when you have perfectly good legs? Are you a wimp? When will you "graduate to a real bike?"

I do not think everyone needs an electric bike. There are plenty of people who are young, fit, or live close enough to work/shopping/etc that they are perfectly happy biking by leg power alone. That's great - I own 4 non-electrified bikes, and I use them often, and love them. But I also use and love my electric bike, for a variety of reasons that include: it is fun, it is great when I'm tired, it helps me carry heavy loads on my bike, it is more energy efficient than pedaling (because the food that I eat is transported mostly by oil-powered vehicles), it is great for hot weather, it helps keep me in shape, and it encourages me to ride the bike every single day and for all my errands.

So, my question is, why do the "purists" have to dump trash on the rest of us who find an electric bike practical and useful in our own lives? Excepting when I go on a rant like this one about their anti-ebike views, I don't trash on their choice of bikes. I've never once said "fixies are stupid" (referring to the trendy fixed gear bikes). What is it that compels such folks to have such an anti-ebike stance? I think it stems from the attitude that bikes are all about racing and recreation, and not for real transportation.

I've had multiple customers call up to tell us the same thing. They go into their local bike shop, and ask about an electric assist motor, and the bike shop folks look at them like they are aliens. They walk out, search on the web, and find us.

Seriously, there are many good things about ebikes, and it surprises me that so many in the bike industry in the US are so unaware of these facts:
1. Electric bikes are the most efficient form of transportation on the planet. They get over 2,000 miles per gallon equivalent.

2. Electric bikes encourage more people to ride. They help people who are out of shape, or in shape, get back on the bicycle and get in the car less. This leads to less oil use, less pollution, and a lot more fit people, reducing healthcare costs for us all.

3. A little racing bike is a lot of fun, but it is not meant to carry the items that most people need to carry in their day to day lives. For example: today I used my electric cargo bike to transport my daughter 9 miles each way to and from daycare, I picked up Chinese take out food, I stopped at the hardware store and bought a set of items including a large 3' x 3' screen protector, and I had a change of clothes handy for an important business meeting. I rode over 30 miles, transporting these things with an electric assist, that consumed a total of about 500 watt-hours of power, which costs about $0.07 (seven cents). By comparison, a typical SUV would have consumed 1.5 gallons of gas ($6.00), equivalent to 55 kWh of energy. That is 110 times the amount of energy, and 85 times the cost. A Toyota Prius is better, but still not great: optimistically estimating 50mpg for in town use, it would be about $2.40 for gas (34 times as expensive as my bike, not counting the difference in maintenance and depreciation costs), but more importantly, the Prius would consume at least 22kWh of energy, or 44 times the energy that I used on my bike. Do the purists really prefer that I just keep burning oil?

4. Electric bikes are not very complicated, but for a shop to provide good support and repairs, they do have to understand electricity. I understand why typical bike shops are reluctant in this regard. In our shop, we have a group of people with degrees in Physics, Biology, Computer Science, and (most of) a math degree. With that kind of background, figuring out what's wrong in an electrical system is not rocket science (it's not like what I do in my day job, which is developing computer programs to analyze genomes). But the typical bike person is not versed in volts, amps, power, and etc. I hope someday the USA will get to the point where many bike shops are versed in these things, because that will help all of us. But that will take a lot of time. In the meantime, I just wish those folks who complain about e-bikes being "difficult to fix" would just come out and admit that the reason they are "hard to fix" is because the person making this statement doesn't have the proper training to fix them.

5. I'm not going to "graduate" to a real bike (seriously, I've been asked when I will "graduate")! I have non electric bikes, and I ride them fast and hard. But I ride my electric bike fast and hard too. It is a great bike. There is nothing to graduate to, except an even more advanced electric bike.

C'mon bike purists, let it lie. There are more important battles to fight that affect all of us who bike, like getting better bike facilities and friendliness in our cities.

------

And finally, something that all cyclists should cheer about (electric or not): The "Bicycle Commuter Act" passed as part of the Financial Bailout Package. This provides a tax credit for "Any qualified bicycle commuting reimbursement," of up to $240 per year ($20 per month that the bike is used for commuting). We're not tax experts, but it seems that a bicycle hub motor used in commuting should qualify... (ask your tax person to be sure!)