I'm very skeptical of any EM claiming 45 - 50 mile range on 300lbs of lead. Cut that in half and you are in the right ball park. Either he has much bigger batteries than yours (the EV24a are listed at 50lbs each). Or you are riding on very flat ground (you are in Florida so that much is a given) at very slow speeds and still doing a bit of fibbing. For a motorcycle to get that kind of range on lead at the typical 40 - 60 mph I ride, it takes a lot of lead. I think by the time you add enough to get that much range you end up introducing all kinds of other design problems. If he is running lithium than I could see it, but not on lead.. damon
> From: [EMAIL PROTECTED]> To: listserv@electricmotorcycles.net> Date: Mon, 5 > May 2008 14:53:23 -0400> Subject: Re: [ElectricMotorcycles] two motor2> > > Jeff is <200lbs and gets 45-50 miles on his. Mine is unknown so far as when> > we had it running in January we only rode it for short distances. I am >200> > so we'll see how it impacts range with my, er, load.> > As far as 48VDC goes, > I think they would run really well on 48 or 72VDC. The> top end might be a > little less, at least with current ratios. We tested> several ratios before > settling on this one. Any lower and the torque at full> throttle is too much > for a street bike. It would definitely surprise people> the first time they > rode Jeff's. Go the other way and the launch was pulling> too many amps for > too long, and wasn't as much fun to ride.> > Hope that helps!> > Shawn> > > -----Original Message-----> From: [EMAIL PROTECTED]> [mailto:[EMAIL > PROTECTED] On Behalf Of SteveS> Sent: Monday, May 05, 2008 2:40 PM> To: > ElectricMotorcycles> Subject: Re: [ElectricMotorcycles] two motor2> > What > kind of range are you getting? How do you think the motor would > perform on > 48V?> > - SteveS> > Shawn Waggoner (FLEAA) wrote:> > I agree with Jeff on the > heavier Series motor idea. My bike is almost> > finished. (I was working on > it at Jeff Patterson's shop last> weekend...sorry> > I have been remiss on > posting any details on the project) The Patterson> > Cycle bikes weigh approx > 620lbs on a custom steel frame and use 6 AGM> > batteries - currently I'm > using 6 Discover Energy EV24A batteries. Jeff's> > original bike was the same > specs just different batteries. When he used a> > standard ADC 6.7" 4 brush > motor it would get incredibly hot after 5 to 10> > minutes of riding - 10 > minutes and you couldn't touch it. We worked with> Jim> > Husted to design a > motor for the bikes. The current motors (in his and> mine)> > are 7.5" 8 > brush series wound motors. They are awesome, after riding till> > batteries > were tired, the motor was only warm. The current setup is using> an> > > Alltrax 72VDC 450A controller and roughly 5:1 ratio on the sprockets. The> > > bike has great acceleration and a top speed of 67 MPH (actual - not> > > calculated). These 7.5" motors are wonderful for the heavier bikes. I> > > certainly would prefer to wire one motor and have one controller for a> > > street bike than two motors and or controllers - lots of extra space and> > > wiring. > >> > You will need to check with Jim, but I think the motors are > right around> > $900 or so - cheaper than 2 PMG's an only one set of > contactors and one> > controller. > >> > I took some pictures after the work > on Saturday and will get them posted> > soon...> >> > Thanks,> >> > Shawn> >> > > -----Original Message-----> > From: [EMAIL PROTECTED]> > [mailto:[EMAIL > PROTECTED] On Behalf Of Jeffrey> > Blamey> > Sent: Monday, May 05, 2008 1:43 > PM> > To: ElectricMotorcycles> > Subject: Re: [ElectricMotorcycles] two > motor2> >> > Having over 1300 miles on the PMG-132 in a light(er) bike > aprox.> > 440lbs and a <200lb rider I find the heat generated in the motor to > be> > controllable with the small fans and shroud I made. Where am I going> > > with this, oh yeah. If I were trying to build a bike based on a> > heavier > frame I would opt for a larger motor, like a D&D or if you> > have deeper > pockets one of the smaller Warps or a custom motor from> > JH versus a dual > Etek or Dual PMG (2 PMGs will set you back roughly> > $1600 so why not do the > series wound and have the thermal mass to> > handle the required power > dissipation under acceleration).> >> > Jeff> >> > On Mon, May 5, 2008 at 8:04 > AM, SteveS <[EMAIL PROTECTED]> wrote:> > > >> I get the idea of the two motor > system, but how does compare to using a> >> larger single motor? I imagine a > single larger motor would be easier to> >> install and control. The larger > motor would deal with the low speed> torque> >> need, but I wonder about what > happens when you get up to speed? Would a> >> larger motor be less > efficient?> >>> >> - SteveS> >>> >> dale henderson wrote:> >>> >> > >>> The > advantage of a transmission is more power at low speeds while at the> >>> > > >> same time reducing the power needed. But once you are up to a cruising> >> > > > speed> > > >> the transmission does not any help except for allowing the > motors to> >> > > operate> > > >> at high efficiency at more than one speed. > The disadvantages of a> >> transmission are increased drag, or lower overall > efficiency and> increased> >> weight.> >> > >>> The advantage of a two motor > system is that a second motor is often, if> >>> > >> not always, lighter, > smaller, simpler and more efficient than a> >> transmission. The disadvantage > of a two motor system is increased power> >> requirement.> >> > >>> Here is > another way to look at it: if your main concern is high> >>> > > efficiency> > > > >> at a particular cursing speed [e.g. highway travel] then longer you> > travel> >> the less efficient a transmission becomes and conversely the more> > >> > > efficient> > > >> a two motor system becomes. A transmission only > increases efficiency> >> > > during> > > >> acceleration once you are at a > steady speed the transmission reduces> >> efficiency in terms of drag and > weight. While a two motor system is only> >> less efficient during > acceleration, so if you have little acceleration> and> >> > > a> > > >> lot > of steady speed then two motor system is overall more efficient.> >> > >>> > Here is a very simple model; if it gives good results then a closer> >>> > >> > examination would be warranted: take a 25-mile highway trip, we'll give a> >> > > > ¼> > > >> mile acceleration; more simply a 100-mile trip with 1-mile > acceleration.> >> > > At> > > >> any give time the motorcycle needs X power. > A transmission is 5% less> >> efficient than a non-transmission so over 100 > miles it will take 100> miles> >> > > *> > > >> .05 = 5 units more power. The > two motor system will take twice the power> >> > > at> > > >> acceleration 1 > mile * 2 = 2 units more power. But if you are commuting in> >> stop and go > traffic then a 40-mile commute might have over a 1 of> >> acceleration. So a > transmission is 40 * .05 = 2 units and a two motor> >> > > system> > > >> is > still 2 units. So if your steady speed is more 40 times longer than> >> > > > your> > > >> acceleration then a two motor system is more efficient. But if > your> steady> >> speed is less 40 times more than acceleration then a > transmission is more> >> efficient. A closer study is needed and results will > vary based on> >> rider/bike/weight/route/etc… but I think it will be clear > that in short> >> > > city> > > >> travel a transmission is more efficient, > but in longer highway travel a> >> > > two> > > >> motor system is more > efficient. But since an electric motorcycle has a> >> finite range and can't > be filled up at the pump then it should be built> to> >> be the most > efficient for the longest-range option. Hence once you get an> >> electric > bike going over 50 miles on a charge [i.e. lithium] and you have> >> some > plans to travel on the highway then a two motor system is the best> >> > choice. Further with a 100+ mile range, city travel never be a concern,> >> > > > even> > > >> with the lower efficiency of the two motor system, but when a > long trip> on> >> the highway is needed the two motor system will shine as it > will give you> >> more range than a transmission.> >> > >>> harry> >>>> >>> > Albuquerque, NM> >>> http://www.austinev.org/evalbum/1179> >>> > http://geocities.com/solarcookingman> >>>> >>> > ------------------------------------------------------------------------> >>> > Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try> >>> > > > it> > > >> now.> >>> >> > >> > <http://us.rd.yahoo.com/evt=51733/*http://mobile.yahoo.com/;_ylt=Ahu06i62sR8> > > HDtDypao8Wcj9tAcJ%20>> > > >>> > ------------------------------------------------------------------------> > >>>> >>> No virus found in this incoming message.> >>> Checked by AVG. > Version: 7.5.524 / Virus Database: 269.23.8/1415 -> >>> > > Release> > > >> > Date: 5/5/2008 6:01 AM> >> > >>> > >>> >>> >> > >> >> >> >> >> > > > > > > _________________________________________________________________ Windows Live SkyDrive lets you share files with faraway friends. http://www.windowslive.com/skydrive/overview.html?ocid=TXT_TAGLM_WL_Refresh_skydrive_052008
