Bionx: Advertised range per charge may be too low

[Zeuser]

I was quite surprised by this. It seems that the advertised ranges for the Bionx may be too low.

I have a PL350 (36V Li-ion battery with 350W motor). Assistance mode #4 is advertised as 35km. That seems way too low. I just got back from a ride which clocked in at 54km. I was using assistance mode #4 all the time and I often used the thumb throttle when I hit lots of pedestrian traffic on the lakefront paths.

When I got home my battery idicator was down to zero bars left and I had clocked 45km. I jammed the thumb throttle all the way down and just did a few laps around my neighborhood totalling an extra 10km. Only when the bike was moving too slow for me to retain my balance did I stop. But then I simply pedaled with assistance mode #4 and despite the battery being really low, I could still feel the push of electric assist helping me out all the way to 30km/h.

The controller never shut down. You really... and I mean... REALLY have to run the battery to it's last "mah" (miliAmp per hour) for the controller to turn off.

The conclusion I came to: that advertised 35km (page 21 in the Bionx book) is REALLY conservative. I was using the thumb throttle a lot and I got more than that. If one were to use assistance mode #4 alone (no thumb throttle) I suspect one could go past the 60km range with still some juice left.

Conditions were: 190lbs rider with fully laden bike (GPS, watter bottle, saddle bags, rack bag, BLT lead-acid headlight and horn), 30-something ' C weather, very humid, mix of downhill and uphill, lots of regen braking, lots of full speed riding, average speed of 25km/h... which is faster than anyone else out there in this heat. I passed about a hundred riders and never got passed once; so I was going pretty fast when I was going. 38-40 km/h was not uncommon.

This was some real world driving and I got better results than advertised. I know that most times advertised ranges are actually lower in the real world, like the EPA ratings on Hybrid cars, but in this case, I got better results than what was advertised.

I'll have to repeat the route again to confirm the results.

Battery is being charged. Lets see if it takes the advertised 3-4 hours to recharge.

I have every reason to believe that Bionx's claim of 90km on assist mode #1 is realistic and perhaps even underrated. I think it can go a full 100 to 110 km on assist mode #1.

Any other Bionx owners see similar results?

PS: I forgot to mention: My Bionx controller is slightly "hacked". The limiters have been removed and other adjustments have been made. Check the "Bionx hack" thread for details.

[geebee]

It all depends on the rider, if you use the motor as an assist you will get massive range, if you let the motor provide most of the power your range plummets.

[adamtki]

I'm jealous. I wish I got the 350 instead of the 250 system. What was I thinking?

I typically run at assist mode 3 with my 250 system and I get around 24 miles which is what is advertised on the site. However, I didn't run it until it turned off. I'm 150lbs and I usually provide a lot of assistance with the motor. My tires are 700x32c.

[redden]

Using this calculation(ahxvolts=watt hours) and assuming that 250 watts will give 18mph average a BionX 36 volt system would give a range of just under 25 miles, so to get 60 does that mean minimal assist and how much does the generation setting on down slopes add to the range?


Do geared systems offer better range from the same battery?

[BroadwayJoe]

Do geared systems offer better range from the same battery?

Between my geared Panasonic equipped ebike and a hub motor ebike at my other home - both the same wattage - the geared system (Panasonic) is at least double the range from the SAME battery.

[redden]

thank you. That's very helpful

[balitom]

I'd been planning to buy a Bionx conversion kit his spring but got a new 29er instead. What's held me back has been real performance information. Specifically I want some idea how far I can go if I mainly pedal and only use enough assistance to eliminate headwind or perhaps turn an 8% climb into a 5% climb. Can I go 190K on a rolling route faster with moderate assist than on a bike with no assist, or am I going to end up pedaling the extra weight most of the way.

[redden]

I am still in the education process but it seems that when it comes to assisted riding the results will vary but the watt hour calculations can give you an idea. One of the things that turn me off about hub systems is the weight of the wheel. My test ride was on a smooth road so it didn't show the disadvantages of such a heavy wheel. I suspect a little off roading would make it very apparent. I know that racers spend big bucks to keep the weight of the wheel down.

[cerewa]

I know that racers spend big bucks to keep the weight of the wheel down.

Because wheel weight hurts your accelleration... when you are not running under motor power.

When you DO have motor power, the acceleration you lose due to wheel weight becomes a trivial matter if you aren't racing.

[redden]

It's not just acceleration, it's handling too.

[cerewa]

It's not just acceleration, it's handling too.

In my opinion, heavy motorcycle wheels handle just fine. But perhaps others disagree.

[redden]

Go to any road race track and ask how many opt for heavy wheels

[adamtki]

While the bionx wheel feels heavy compared to a regular bike wheel, only the outer shell and the ring of permanent magnets just inside the outer edge spin with the wheel. Most of the hub's interior does not spin.

What I did notice with the bionx system is that it's actually *harder* to go above 25 mph than a regular bike. That's because of the electromagnetic resistance is greater than what the controller can provide. There's a term for this which I can't remember.

So basically, on any downhill a regular bicycle with the same tires can fly past a bionx bicycle.

[Abneycat]

As the weight of the BionX is at the center of the wheels radius as opposed to rotating about the rims, it has *very little* effect on the handling of the bicycle, at all. In fact, you can take a considerably heavier system like a Crystalyte front mounted and it really isn't hindering. At that point it may simulate a slightly more relaxed steering tendency, but nothing else.

Balitom,
If I were going on a long trip which exceeded the range of the system, the drag for me would literally be the drag - not the weight. 13-15lbs is gravy at speed and not going to ruin your life on a hill, but the constantly engaged design of a direct drive hub motor is about the same as having a constant drag force, much like a dynamo but much more pronounced. For a system which might not go the whole run, something which freewheeled when not in use would be far preferable.

[balitom]

Abneycat,

So are you saying there is no freewheel mode with the Bionx. I'd hoped it would freewheel on the flat and downwind without drag. Then I could tolerate it slowing me on descents, while it charged, knowing I'd be enjoying a little leveling of the hills and reducing of headwind drag.

[Abneycat]

There is no freewheel mode, correct. The nature of the BionX motor which allows it to have no internally moving parts, silent operation and regenerative braking also mean that the motor is constantly engaged and will cause rolling resistance when not in use - that said, the level of resistance can vary with each brand of motor and design, and I find BionX to be fairly decent.

as said, its not a murderous amount of drag (the bicycle can still be operated near-normal), but you *definitely* feel it. I would most certainly put non-freewheeling over weight as something to be concerned about with a motor which wouldn't be used all the time.

Regenerative braking isn't a great feature, its an "extra" which can be nice to have, but you'll probably get only about 3-5% more range from your ride depending on the hills you meet. Comparatively, a geared motor which can freewheel will save considerably more energy than that *without* regenerative capabilities simply because it rolls better for the rider and typically has a much better output to weight ratio.

[BroadwayJoe]

Regenerative braking in this industry has become a "fluff" item IMO. I doubt it delivers 3-5% range improvement in real world riding while the potential to cook batteries and/or controllers = 100%. It's sales engineering for the folks that want to believe in perpetual motion. Nice in theory - in practice not so much...

[redden]

I'm leaning heavily away from the hub systems. What are the options available in the US short of the 5-7k optibike?

[Abneycat]

Frame mounted motors such as Cyclone, Currie, and eLation, they utilize the drivetrain of the bicycle - and as such, operate in more than one gear ratio which allows them to have good efficiency in most situations. There are ways to use a direct drive motor in the same manner ala Stokemonkey, but these are uncommon.

You could also go with a geared hub as opposed to a direct drive one. It would freewheel.

[mostlybent]

Regenerative braking in this industry has become a "fluff" item IMO. I doubt it delivers 3-5% range improvement in real world riding while the potential to cook batteries and/or controllers = 100%. It's sales engineering for the folks that want to believe in perpetual motion. Nice in theory - in practice not so much...

So true,
I have a 350 Bionx and the regen braking is nice, but it's also the most prone to failure because the sensitive proximity switch located on the brake. It will lock (regen mode) your rear wheel if knocked out of kilter. But the same lock feature prevents theft.

Hub motors in general are a great design for the reliability factor, they are near bullet proof and never wear out. Also completely silent if non geared type.

The original poster saying 90km range is rediculous, you have to pedal the first 70 km to reach that goal.

Bottom bracket design electric bikes are good on paper but are prone to drive train failure because bikes are not designed for 1,500 watts of power constantly through a tiny chain, never mind the freewheel.
Plus the annoying noise of the reduction gearing before it even reaches the sprocket.

[Harbournet]

You don't need to have a geared hub to have freewheel capabilities. The bike i ordered is a brushless DC Hub that freewheels fine - best of all it's almost silent, as opposed ot the geared 'whine' - plus virtually maintanence free.