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Author Topic: 2008 GPR-S Review  (Read 4303 times)

Richard230

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2008 GPR-S Review
« on: May 12, 2010, 10:14:46 PM »

Hello. My name is Richard Harmon and I live in Pacifica, California. I have been riding motorcycles almost every day for 48 years, during that time I have owned 40 IC motorcycles. I have been posting on El Moto for the past 9 months and only recently located this site (I am not too computer savvy). As my first message I thought I would post a review of the GPR-S that I owned last year. I wrote a longer and more general version of this article for a BMW club magazine in Vermont and was ready to contribute part II, but it was never printed. I guess BMW riders in New England are not quite ready for electric motorcycles. However, I have high hopes that you will find my comments interesting and informative.

In August 2009 I purchased an electric motorcycle. It was a 2008 model production Electric Motorsport GPR-S, manufactured in March 2009. I it bought from the Electric Green Showroom in San Carlos, California, a block north of the Best Buy store which now sells the Brammo Enertia in the Bay Area. The store had been open for about 6 months and I was told that my bike was the third GPR-S they had sold to date.

An announcement from Electric Motorsport in the fall of 2008 regarding the start of their firm’s production of electric motorcycles was described as follows: “The Electric Motorsport GPR-S is the first DOT compliant, street legal electric motorcycle capable of doing Freeway speeds. The Electric GPR-S is a Joint venture between Electric Motorsport and Tiger Motors. Tiger Motors builds the Electric GPR-S chassis exclusively for EMS. Final assembly is at the EMS facility in Oakland California”. Tiger Motors is a small motorcycle manufacturer in Thailand that builds a range of 50cc to 250cc motorcycles and an Asian version of the GPR-S called the e-Boxer.

During the first month I rode the bike some 200 miles, mostly back and forth to work. I was quite satisfied with the bike’s performance. A top speed run on the local freeway netted me a speed of 62. The bike ran right up to this speed and just would not go any faster. I believe that motor was limited by its maximum rated rpm and the gearing of the final drive. The maximum draw that I saw on the Cycle Analyst screen was almost 200 amps at around 50 mph, which seemed to be very good performance from the bike’s 20 Hi Power 50Ah batteries. The bike accelerated slowly upon starting from a stop when going uphill, probably due to the controller’s programming. But once you got moving, it would climb any hill and could keep up with expressway traffic – at least up to 60 mph. The throttle response was a little spastic, with noticeable surging on level ground (sort of like my old 2000 R1100R), but I got used to it after a while. The standard model GPR-S does not have regenerative braking, so going down the many hills in my area meant that my brakes got a workout, but they performed quite well. The Tiger brakes, which appear to be a copy of 1980’s era Brembos, seemed to be up to the task though. Going downhill uses no battery power, which is helpful. I liked the very low running noise and lack of vibration.

The quality of the GPR-S chassis is only fair, compared with the other modern Japanese and European motorcycles that I own. Everything is made in Thailand, of course, even the 90/80-17 front and 100/80-17 rear tires. The rear shocks appear to be stylized copies of Ohlins piggybacks, but of course they don’t work as well. The springs were way too stiff for my weight and the stiff springs overwhelmed the rebound damping of the shocks. Everything on the bike is made of either aluminum or plastic, except for the main frame, motor and battery mounts. The front suspension is sort of cute. It is an Ohlins upside-down fork look-a-like, not exactly something needed on this bike and the travel is quite short, maybe about 4”. However, the suspension and tires work just fine within the performance envelope of the bike and support my 145 pound weight with no problems.

But again, the forks were over sprung and under damped. The heavily-braced aluminum rear swing arm was particularly impressive. The bike has a rated carrying capacity of 560 pounds! (This is more carrying capacity than even my BMW R1200R is designed for.) But I think everything on the bike, including the motor, would be overwhelmed if you ever tried to carry that great a load.

The Electric Motorsport GPR-S is a lot of fun to ride in light traffic. Its light weight of 280 pounds and low center of gravity (due the low placement of the motor and batteries) makes the bike very easy to ride, although the seat is a bit narrow and legroom on the bike is tight for a typical American male. It is slightly smaller than a Kawasaki 250 Ninja and has almost exactly the same performance as a current-model Vespa 150 motor scooter, but the GPR-S handles and rides much better than the scooter and goes up hills without slowing down.

A full recharge, using the bike’s on-board charger, of my 20 cell Hi Power (Chinese brand name) lithium-ferrous-phosphate batteries took about 4 ½  hours The brains of the outfit is a 72 Volt, 300 Amp Alltrax Controller. My ride to work is 10 miles and I have to go up and down three long hills to get there and back at expressway speeds. I typically used about 15 AH in each direction while keeping up with traffic at around 50 mph. The manufacturer recommends not using more than 80% of the battery capacity, or 40AH before recharging, in order to get maximum life out of the batteries. The batteries are rated by the manufacturer as being able to accept up to 2500 charges before needing replacement. That is a lot of riding when you are pretty much chained to a 15 or 20-mile radius.

I had no problems insuring my bike, other than I was told that this was the first electric motorcycle that my insurance company had insured. Because I own so many motorcycles, have a clean driving record, am over 62 and only have them insured for liability (being self-insured really saves me a lot of money each year on the other 6 motorcycles that I own), the GPR-S only cost me an extra $5 (!!!) per year to insure. What a bargain!

This is the perfect vehicle for commuting to work, if your work place is not more than about 15 or 20 miles away. At my workplace I can park my bike next to my office window and run a 25 foot extension cord, connected to my desk outlet, out the window to “refuel” the bike for a worry-free full throttle trip home.

Unfortunately, my GPR-S met an untimely “death” after only 300 miles of riding. I decided to try for a maximum performance run to the local shopping mall. This involved a full-throttle run on a freeway for 10 miles and back, which included a 3-mile long 6% hill. The GPR-S performed really well on this ride. It was able to go up the freeway hill at 55 mph, which was exactly the same speed that my 1969 Yamaha 350cc YR2-C would climb that same hill. By the time I returned home, I had used 37 Ah and the batteries were starting to sag a bit. I plugged in the on-board 8 amp charger and recharged the batteries. During charging I noticed the smell of burning insulation, although charging proceeded normally. However, after my next ride the charger would no longer work. The problem was ultimately found to be a toasted BMS and was apparently not something easy to repair. Eventually, I sold this bike back to EMC for a new 72-volt, 50 Ah Sepex model GPR-S, which I purchased in January 2010. I will report on my new GPR-S model soon. It has the latest design BMS and has been functioning well over the past few months. I have over 800 miles on the clock so far and will report on its performance when it reaches 1000 miles.
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Richard's motorcycle collection:  2014 14.2 kWh Zero S, 2016 BMW R1200RS, 2011 Royal Enfield Bullet 500 Classic, 2009 BMW F650GS, 2005 Triumph T-100 Bonneville, 2002 Yamaha FZ1 (FZS1000N) and a 1978 Honda Kick 'N Go Senior.

Richard230

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Re: 2008 GPR-S Review
« Reply #1 on: May 13, 2010, 02:13:57 AM »

One fact that I forgot to mention is that my 2008 model GPR-S was powered by an Etek-RT motor, whereas the latest standard production 2009 72V, 40Ah GPR-S uses an Etek-R motor and Thundersky batteries. It is my understanding that the R motor has less torque, but revs higher than the RT. But I can certainly vouch for the RT when it comes to uphill pulling power.
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Richard's motorcycle collection:  2014 14.2 kWh Zero S, 2016 BMW R1200RS, 2011 Royal Enfield Bullet 500 Classic, 2009 BMW F650GS, 2005 Triumph T-100 Bonneville, 2002 Yamaha FZ1 (FZS1000N) and a 1978 Honda Kick 'N Go Senior.

Phantom

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Re: 2008 GPR-S Review
« Reply #2 on: May 13, 2010, 07:28:31 AM »

...riders in New England are not quite ready for electric motorcycles. However, I have high hopes that you will find my comments interesting and informative.

I am from New England and I did find your article interesting and informative.

Hi Richard, welcome to the forum. I have read your posts at elmoto.net and you have taught me a lot. I recently ended my lurker status over there.

I would try to push your article again with that same publisher or others. It is really good.
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Richard230

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Re: 2008 GPR-S Review
« Reply #3 on: May 13, 2010, 07:49:13 AM »

Thanks Phantom for the kind words. However, now that EMS has moved on and the 2008 model bike is now yesterday's news (to say nothing of now being called a "Native" GPR-S as the brand name), I plan to write about my Sepex GPR-S as my next project. At least then I won't have to try to keep my current and past tenses sorted out.

My feeling is that the EV market is not quite mainstream yet. There really are not very many non-technical motorcycle riders buying these bikes yet, due to their high prices, relatively low performance and the low price of gasoline. Once gas prices spike again, which will happen sooner rather than later, then I think IC motorcycle owners will be more interested in reading about plug-in motorcycles. By then the few remaining bugs should have been worked out of most production bikes, production capacity will be greater and sales will pick up. That is when these sort of product reviews will be appreciated by interested potential EV purchasers.
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Richard's motorcycle collection:  2014 14.2 kWh Zero S, 2016 BMW R1200RS, 2011 Royal Enfield Bullet 500 Classic, 2009 BMW F650GS, 2005 Triumph T-100 Bonneville, 2002 Yamaha FZ1 (FZS1000N) and a 1978 Honda Kick 'N Go Senior.

guity

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Re: 2008 GPR-S Review
« Reply #4 on: May 13, 2010, 11:20:57 AM »

Nice review Richard!  Thanks!  And all this time I just assumed that you didn't care for this forum for some reason!
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picasso

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Re: 2008 GPR-S Review
« Reply #5 on: May 17, 2010, 05:28:56 AM »

So why does the 2008 have a BMS and the 2009's don't?
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Harlan

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Re: 2008 GPR-S Review
« Reply #6 on: May 17, 2010, 07:31:15 AM »

So why does the 2008 have a BMS and the 2009's don't?

All the lithium powered EMS bikes have a BMS.
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Harlan Flagg
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Richard230

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Re: 2008 GPR-S Review
« Reply #7 on: May 17, 2010, 07:49:31 AM »

The 2009 bikes have a solid state BMS board that fits over each group of 4 batteries. So far this new design seems to be working very well.

According to information that I picked up on the El Moto forum: the EMS BMS used in the 2009 models was designed and built by Nathan Mariels of Modalis engineering for EMS. I would post a photo of this circuit board but my photos are too large to be accepted by the attachment system and I don't know how to downsize them. However, it looks like a white plate fastened over each group of 4 batteries . The plate is covered with electronic solid state devices and has red and green lights that flash to indicate what is going on with the BMS. It looks quite sophisticated.
« Last Edit: May 17, 2010, 08:11:40 AM by Richard230 »
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Richard's motorcycle collection:  2014 14.2 kWh Zero S, 2016 BMW R1200RS, 2011 Royal Enfield Bullet 500 Classic, 2009 BMW F650GS, 2005 Triumph T-100 Bonneville, 2002 Yamaha FZ1 (FZS1000N) and a 1978 Honda Kick 'N Go Senior.
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