Performance and Range test of Magnum Metro+ Electric Bike

Rather than post test results to my website, Court and I have an agreement where I will post test results here in the EBR forum and he will help get bikes to me for testing. In the spirit of openness and transparency, he has compensated me for this test (and the Faraday Cortland electric bike test). In the future, I'll work directly with the bike manufacturer or retailer regarding compensation for test results.

Here are the test results for the Magnum Metro+ Electric Bike:

Performance and Range Test Results

  • Braking Distance from 25 mph: 42.9 feet
  • Brake Fade: Moderate
  • Real World Range on Highest PAS (PAS 6): 38.7 miles
  • Real World Range on PAS 4: 42.7 miles
  • Max Speed Throttle Only: 20 mph (adjustable)
  • Zero to 5 mph Throttle Only: 2.0 seconds
  • Zero to 20 mph Throttle Only: 12.4 seconds
  • Max Assisted Speed: 25 mph (adjustable)
  • Zero to 20 mph with zero effort spinning: 10.7 seconds
  • Zero to 23 mph with moderate pedaling: 11.8 seconds
  • Throttle only hill climb: 0.71 miles before stopping at 3:20 (average speed of 12.7 mph)
  • 100 Watts of pedaling hill climb: 4:50 to climb 1 mile Ice Pond hill, average pedal power output of 99 watts, average speed of 12.2 mph.
Ebike Specs of Note

  • Motor type: Rear wheel mounted geared hub
  • Rated power: 500 watts
  • Battery Details: 48 volts, 13.0 amp-hour = 624 watt-hours
  • Battery amp-hour: 13.0 amp-hour
  • Total Weight: 59.1 lbs
  • Cadence or Torque: Cadence only
  • Mileage at time of test: ~1,600

For all of these tests, the power setting was set to “normal”, note that the power setting can be changed to “economy” and “power” to allow for different performance curves. I’ll evaluate those differences in a later post.

Brake Testing

Brake testing is probably the most important factor, at least when it comes to safety. With the higher speeds that ebikes can achieve, braking becomes critical. And with the advent of ABS systems for ebikes, manufacturers are catching on to the importance of good brakes. This test appears very simple, achieve the desired speed, then simply stop as quickly as you can. For the Metro+, this means pulling the front lever enough to lift the rear wheel while the rider (me!) is trying to keep their weight back to keep the rear wheel engaged to the ground. The rear brake is engaged fully as well, which usually results in some skidding until it leaves the ground. It takes practice to get it right! And every ebike rider should practice emergency stopping from top speed on different road conditions when and where they can safely do so.


The Metro+ stopped at an average distance of 42.9 feet from 25 mph (it’s top assisted speed). After four hard stops, moderate brake fade was noticed with the fifth and sixth stops requiring significantly more lever force to achieve maximum braking. Brake fade can happen to any brake as the friction surface becomes too hot to remain as effective as when cold. Better friction materials can prevent this. However, in real world use, it’s unlikely that one would need to use the brakes repeatedly enough to notice brake fade.

Real World Range Tests

For the real world range test, the battery was charged to 100% using the supplied charger and then the ebike was ridden with the same PAS setting for the duration of my commute. Most of the ride is on the Putnam and North County trailway, which are paved and do include several road crossing requiring full stops. Both trailways can be quite rough in some spots so maximum speed isn’t always maintained. In addition, the trail can be busy with runners, walkers, dogs, and other bikers. There is plenty of elevation change but it’s mostly gentle slopes as the trailway follows on old rail line. Remember, this represents real world use.


For the PAS 6 test, the rider (myself) and stuff (laptop, water bottle, lunch, etc.) weighed in at 210 lbs, the average temperature over the ride was 62 degrees F and the trail was mostly dry. The tires were inflated to the maximum sidewall pressure (80 psi) as is my custom. I started with a full charge and ended with the battery voltage at 44.8 volts, which is a state of charge of roughly 25%. I traveled 36.3 miles at an average speed of 20.8 mph, and I averaged 150 watts of output with an average cadence of 80 rpm. I climbed 1,119 feet during this ride, but the elevation at the end is 570 feet lower than the starting point., an average slope of -0.3%. By extrapolating to a 20% state of charge, the maximum range on PAS 6 of 38.7 miles can be calculated. The average power consumption from the battery works out to 12.9 watt-hours per mile. I spent the majority of the ride in a usual riding position but I do place my elbows on the grips in sort of a makeshift aero bar position for perhaps 20% of the ride. I find it helps to change positions to avoid stiffness. This position does improve the aerodynamics some and should be noted.


PAS 5 test: Same route as above, my AM commute. It was colder, average temp of 47 F. I averaged 19.6 mph, 145 watts of human input, and travelled the same 36.3 miles as the above PAS 6 test. The battery started with a full charged and ended at 45.4 volts, or 31%. By extrapolating to a 20% state of charge, the maximum range on PAS 5 (with 145 watts of human input) would be 42.1 miles. This works out to an average consumption of 11.9 watt-hours per mile (really not that much different than the PAS 4 test – although that test had more elevation gain).


PAS 4 test: I rode home from work (the reverse route of the morning). It was warmer so the average temperature was 72F. I traveled the same 36.3 miles all on PAS 4, and ended with a battery voltage of 45.5 volts, which equates to a 32% state of charge. I averaged 18.4 mph, 147 watts of pedal power at 78 rpm, climbed 1,617 feet, and the overall slope was +0.3% (opposite of the morning). By extrapolating to a 20% state of charge, the maximum range of 42.7 miles can be calculated. The average power consumption for this ride works out to 11.8 watt-hours per mile.

Road Load Range Evaluation

For the road load range evaluation, the bike is simply pedaled with zero assist at 10, 15, 20, and 25 mph (or higher). The power required to move the bike at each speed is then determined and an equation is developed to represent that relationship. The Metro+ results are below:



Once this is determined, one can calculate the power required to maintain the speed of each each PAS setting:

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Once the power required is known, the range in miles for each PAS and rider input can be calculated, results for the Metro+ below:

1563200608884.png


This road load range should differ from the real world range as it assumes a constant steady state speed over level ground with no coasting. In real world usage, many variables can affect road load and range.

Acceleration Test Results

The acceleration test is fairly straight forward, how fast does it get from zero to the desired speed?


  • Max Speed Throttle Only: 20 mph (adjustable)
  • Zero to 20 mph Throttle Only: 12.4 seconds
  • Max Assisted Speed: 25 mph (adjustable)
  • Zero to 20 mph with zero effort spinning: 10.7 seconds
  • Zero to 23 mph with moderate pedaling: 11.8 seconds

While the max assisted speed is 25 mph, this ebike will barely achieve that without rider input over level ground. Therefore, the measured time to 20 mph is recorded with zero effort spinning, which activates the cadence sensor. It’s interesting that it’s faster with zero effort spinning, this is most likely due to the little bit of inevitable torque applied to the pedals while starting out. You’ll also note that the acceleration to 23 mph is recorded with moderate pedaling effort (about 150 watts). Once the battery is not fully charged, the Metro+ struggles to hit 25 mph so 23 mph was used.

Hill Climb Performance

For the Hill Climb Test, the Metro+ climbed 0.71 miles up the mile long Ice Pond hill using only the throttle before coming to a stop. It’s average speed for this portion was 12.7 mph. For the 100 watts of pedaling portion, I averaged 99 watts of pedaling input and it reached the top of the hill in 4:50 at an average speed of 12.2 mph.

I should have some more test results coming, mostly additional real world range tests. As those are completed, I'll update this post.
 

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