Unagi Model 1 E500 Dual Motor: Reviewed!

24-Dec-2024

24-Aug-2021 : Initial edit

New TL;DR: THROW AWAY YOUR UNAGI SCOOTER

A few weeks ago, I was riding my 3 year old Unagi E500 scooter on the street at about 16 mph when without warning, without any brake lever input, full brake action -- almost lockup -- was applied for about 200 milliseconds and then released. I was thrown forward from the scooter into the road. I was uninjured -- but had a car been behind me, I would have been killed.

I did not know what happened. I walked back some distance on the road; had I hit a pothole or major street imperfection in the dark? I hadn't. The resurfacing of this stretch of road on West End Avenue is actually pretty new. The unit had turned off so I turned it back on. With some hesitation, I started off but kept my speed to about 6-8mph.

Two blocks later, the lockup happened again, although this time I was moving slow enough that I was able to recover. Moments after, I looked at the console and it read "E6" and then slowly faded to black. The unit would not turn back on. I walked it home.

Research reveals the E6 error code means controller failure and therefore I certainly was not going to get back on the scooter until it was repaired. I asked Unagi to fix it gratis but I would pay for shipping; they politely declined.

I had the battery replaced last spring (Apr 2024) and did not want to spend more money on the repair so I took the scooter and its charger to the DSNY e-waste site and junked it. Why not give it away? Because I realize now it is very, very dangerous for the computer to be controlling the brakes. You want to have your throttle separate from the brakes and have the brakes be powerful enough to at least somewhat slow down a runaway throttle. When I first got my Dualtron Spyder 2 I thought the mechanical brakes were "ancient" and clumsy compared to the Unagi electric brakes; now I realize the value of the separation.

TL;DR

A superb scooter to handle the "last mile or two" problem in commuting or going a few blocks and back very quickly -- but it won't go far.

Always start with The Good Things

I did extensive research on the electric scooter market, had specific requirements, and knew what I was getting into with the Unagi Model 1 E500. After 8 months and 500 miles of ownership, here are my observations:

Highly portable. This was my #1 requirement. Only 26lbs, compact design, trim (only 2 short external cables, no sharp edges, remarkably few protrusions, etc.), and fast-foldable, the Unagi transitions between road and not-road with aplomb.
- On the NYC Subway, I fold it and stand it on its front wheel and tuck it in between my legs. Standing or sitting, the result is a footprint barely larger than my body. No angry glances.
- A few stairs ahead of you? Don't even bother with folding and fussing. Get to the obstacle, then just lift by the handlebar stem and walk over it and then put the unit down and continue scooting. In no time this becomes second nature and makes for a very highly mobile, efficient transit.
- The unit is compact enough that it doesn't scare people on sidewalks on those occassions when you need to do a bunch of yards there. Just slow down and it is easy to gracefully navigate along with and then through the bipeds.
More than fast enough for the bike lane in NYC. Top speed is 19-20mph and that is too fast for narrow bike lanes in NYC.
Impressive pickup and hill climbing ability for a small scooter. There is only 500W nominal power output to the dual motors yet I climb the hills of Central Park and the Upper West Side at 16+mph. I can even tackle the steep grade in the car parking facility at 9 mph.
Electric braking is very good but cannot approach the deceleration of physical brakes applied in a controlled emergency stop. As a bicyclist, I know.
Yes ... it is a very nice looking unit. The deck in front of the rear wheel enclosure is less than 1 1/4 inch thick. From the side at a few feet away it looks impossibly thin, an effect further reinforced by the additional thinning of the rear wheel support arms. The handlebar integrated dashboard is slick but also helps reduce external clutter: snag points, cables, etc.

As fond as I am about the unit and would recommend it to others, one must consider another factor: range.

Figure on a maximum usable range of 7 miles under the BEST circumstances

The Unagi website has this to say about range:

The Unagi Model One, for example, lists a range of 15.5 miles (25 km) for both its single-motor E250 and dual-motor E500. Some scooters will list a slightly lower range, some higher. But it's important to understand that this is only an estimate and may not represent real world conditions. Achieving optimal range depends on a number of variables, including scooter weight, rider weight, terrain, average speed, battery size, motor size, and motor efficiency. Electric scooter manufacturers calculate range using a few basic assumptions that may not apply to many riders, including a weight of around 165 lbs (75kg), an average cruising speed of around 12 miles per hour, little to no wind, and dry, flat terrain.

Most of my scooting is relatively short, using both motors and top speed, and then recharging the unit in the evening. That works fine, but it began to irk me that I was routinely using 75% of the battery charge after only a few miles of scooting. I decided to perform a controlled experiment:

The unit was fully charged.
The speed control was set to level 2 to max it out at 12mph -- just like the range conditions standard suggests.
Single motor mode was used.
Outside temp 55F.
A 0.5 mile downhill ride on asphalt was made to Riverside Park. There is a wonderful flat 0.4 mile asphalt paved track that was perfect for just scooting back and forth, back and forth, to drain the battery. Very little braking needed, just constant throttle (but top speed limited) 12mph on flat asphalt. I weigh a bit more than 165 lbs but I assert not so much more that it would materially affect a steady speed test, i.e. no extra energy to stop or accelerate. And certainly no hills.

My expection was not to get 15.5 miles but perhaps 12? Remember: these are ideal conditions.

I got only 7.5 miles before the battery completely gave out.

And the battery indicator went from white bar to red bar very quickly in the last .5 mile and performance suffered significantly, leading to my assertion that the maximum usable range is 7 miles. I walked / coaxed the unit home and did a full recharge and tried again. Again, only 7.5 miles. If this is the result under the best circumstances, then what happens in other scenarios? Read on!

All test scenarios except C are performed twice and averaged.
Unit is run until battery in the red but note: The battery drains very nonlinearly toward the end. On the dual motor high speed test in particular, the meter skipped over red from 1 white bar to blank and then the unit started to periodically emit the warning beep. Performance errodes very quickly in the red. In general, you have to assume that 1 white bar means you are practically empty.

Scenario Codes:

A: Riverside Park loop constant speed test. Flat, smooth surface. 0.4 miles up and back for a full loop of 0.8 miles.
B: Lower Loop, Central Park, constant speed test. Rolling hills and dips, nothing too steep, smooth surface. 1.7 miles.
C: Complete Loop, Central Park, coasting sometimes. Cat's Paw Hill and North Woods Hill figure prominently here. 6 miles.

# motors	Top Speed	Scenario	Usable Range	Notes
1	12	A	7	The Best Case
2	19	A	6	Something of a surprise here: only a 14% reduction in observed maximum range for dual motor and top speed! The battery drain at the end is significant; at 1 white bar on the meter, you had better be close to a charger because it will go red in about 0.7 miles.
2	19	C	5	Not surprising that rolling hills would reduce the 6 mile range on flats even further. The meter went from 1/4 to zero (not even red) and the 3-beep warning started at 4.5 miles. Switched to single motor mode and interestingly enough, managed to go another 1.3 miles to get home, and the unit did not give out. Unagi has to rework the battery meter algorithm.

Other Important Observations and Experiences

The lack of suspension and (almost) solid wheels demands a bent-knee, body-assist active ride profile. That's fine and after only a short amount of time you get used to this but make no mistake: this is not a luxurious cruising vessel. At speeds below 10mph (which is still over 3X faster than walking), it is far easier to spot and avoid "problems." Faster than that, you have to really be on your game.
The (almost) solid wheels do not behave like inflatable tires. In particular:
- Be very careful about leaning into turns above, say, 10mph on less grippy surfaces -- like poured, smooth concrete in a parking facility. The interface between the hard rubber wheels and the contact medium cannot deal with the big lateral force and the wheels will slip out sideways opposite to the direction of the turn.
- Painted lines -- crosswalks, lane dividers, etc. -- have the same albeit reduced effect as above. Driving in a straight line on an intersection-long white stripe creates a very mild jiggle. You simply have to get used to it -- or avoid it.

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