- Top of the line 500 watt electric bike kit with a focus on acceleration and low end torque for climbing
- Unique center-spoked design for improved comfort and wheel durability, narrow casing accommodates a larger cassette for wide range of pedaling gears
- Offers regenerative braking and four levels of pedal assist and regen mode (for exercise or descending)
- Larger visual footprint with wide diameter, experiences some cogging due to direct-drive setup, increased unsprung weight
The D Series is a fifth generation electric bike motor kit from BionX that offers higher power (500 watts) and more torque than the older PL, SL and S series kits. In this review I test the BionX D 500 DV (the D stands for downtube and V stands for 5th generation). BionX was started in 2000 as EPS (Electric Propulsion Systems) and was acquired by Magna (a Canadian automotive company) around 2008. Since then it has grown into one of the largest high-end manufacturers of drive systems for electric bicycles in the world. I like this kit because it’s quiet, works with nearly any bike and is well balanced. The downtube battery design is more balanced than a rear rack. This system offers regenerative braking, four levels of regen and assist as well as light integration (so you can run everything off of one main power source) and a Deep Sleep mode to protect itself from complete discharge (which is harmful for Lithium-batteries). It’s due out around late August 2014 and can be ordered and installed bike by ebike dealers.
The motor itself is contained inside a plastic composite shell that is thinner than other BionX kits but has a larger diameter. This is because the magnets are distributed further out from the axle to provide more torque through mechanical advantage. The magnets and drive system on the D-Series don’t mount to the shell at all, they are built onto an aluminum wheel attached with four spokes that meet at the axle (this is where the torque sensor lives). In addition to improved low end torque for accelerating and climbing, this narrow design provides more room for a cassette in the rear. It’s ideal for hardtail mountain bikes that need power and gears to really perform as well as responsive power that will start and stop quickly. Another interesting quality of this design is that the wheel containing the motor is center-spoked meaning the spokes are setup like a normal bicycle wheel vs. connecting to the hub motor itself. This provides more flex and give when riding, it feels comfortable and is easier on the rim and tires when going over bumps.
The battery pack I used to test the D-Series is one of the largest and most powerful in the BionX line with 555 watt hours of capacity. It uses trusted Lithium Manganese Cobalt 18650 cells from Panasonic (should last 1,000+ cycles if cared for). BionX offers a solid two year warranty on this part and is known for good service (responding well to an issue in 2012 with a batch of batteries that had a circuit board issue). It’s a big company that’s in it for the long haul, working towards quality and partnering with brands like Smart and BMW as an OEM supplier. Interesting fun fact here, you can see the sticker on the side of the battery that shows three white bars right? These relate to its size whereas smaller packs will just have one or two bars for a quick visual guide on size. This black plastic with honeycomb pattern and bars is their new style for 2014 and I like that they’re also going with simpler names. I asked about heat (black absorbing more than white or silver) and they assured me that the system has been rigorously tested (both the motor and battery) to perform well in all conditions. I was able to tour their factory near Toronto and was amazed that they actually assemble the motors by hand in Canada! That’s pretty rare and awesome in this space where most are assembled in Asia and then shipped across the world.
One of the coolest things about BionX is their cloud computing platform that lets batteries, motors and consoles “check in” when they are connected for diagnostics. It makes troubleshooting, upgrading and warranty service much easier for shops because it can pinpoint issues vs. guess and check. The D 500 uses their second generation console that has a symmetrical design with four buttons built in (thoughtfully created for left or right hand use). Either of the two top buttons activate the display, if you hold down on the top right it activates your lights (if you’ve wired a set in) and you can arrow up or down from there to choose a performance level from -4 to 0 to +4. There’s also a neat break-out console that can be mounted separately with a +, – and variable speed trigger throttle. The entire thing is sleek, flexible and easy to use when riding. I also love that the console itself is powered by the main battery, removable and backlit for use in low light conditions. It’s one of the best display / control systems I’ve ever used, especially for off-road use because the trigger is better than twist throttle on bumpy terrain.
The D-Series motor and associated DV battery pack offer great performance, high quality and excellent balance (for a hub motor system). It’s sleek, smooth and very powerful (the most powerful 500 watt kit I’ve tested to date). I like how zippy it is in any gear vs. mid-drive and appreciate the smooth, efficient torque sensing technology in use. It does take up more visual real estate in the rear wheel and increase unsprung weight compared with a centerdrive but is much quieter and offers regeneration. The downtube style battery pack keeps weight low and centered and is removable for convenient charging or transport which I love. It does take up the space where water bottle cages might otherwise mount but that’s not so uncommon. It can be charged on or off the bike and fits on a range of frames including recumbents, tandems, cruisers and mountain bikes. This is a big step forward in technology from a company that has been around since 2000 and sells products all around the world. Whether you get the kit and work with a shop to have it installed or wait for a third party complete (which will be available in Europe first from Wheeler) this is solid choice.
- Disc brake compatible (narrow hub motor design accommodates larger cassettes as well)
- Very quiet thanks to the gearless design and sound dampening system (quieter than most mid-drives)
- Unique center-spoked design dampens vibration and absorbes shock to improve ride quality and reduce wheel/tire maintenance
- Excellent low-end torque for starting and climbing thanks to wider hub motor design
- Offers regenerative braking as well as four levels of regen mode and four assist levels
- Removable display panel deters tampering and vandalism, display runs off main battery pack
- System will work with wired-in lights so you don’t need to rely on separate batteries
- Display is back-lit and right or left hand accessible (symmetrical design with buttons on both sides)
- Small break-out tactile button pad makes changing assist levels or using the throttle easy
- Solid two year warranty, larger established company (in business since 2000)
- Uses one of the largest and most powerful BionX batteries to date 48 volt 11.5 amp hours (555 watt hours)
- Rear-wheel hub motor exerts force onto the part of the frame that is designed to handle it vs. front hub designs, great if you mount to a bike with a front shock
- Deep Sleep technology senses if battery is getting low or hasn’t been used and completely shuts down to avoid damage (after 2 months of inactivity or 2 weeks if battery is >= 10%
- The D-series will work with any BionX battery but is recommended for >= X (eXtra Long range)
- In kit-form, the wire from your console to the battery and motor may not be concealed as well as a purpose-built ebike
- Increased unsprung weight 8.9 lb motor (4kg) as compared with a centerdrive (mid-drive) electric bike
- Direct-drive setup enables regen but also creates cogging drag compared with geared freewheel designs (this somewhat reduced given the large diameter and flat disc design compared to smaller diameter hub motors)
- Throttle and computer may not mount as easily to road bikes with drop handle bars due to shape and size of tubes and grip tape
- This kit is only compatible with 135 mm axle size so check your mountain bikes carefully or bikes with thru axles. Also, given the larger radius of the motor it is not available in quite as many wheel sizes… other BionX kits come in 20″ and 24″ but this one does not
- Battery pack takes up space where you might otherwise fit a bottle cage, consider a CamelBak
- One of the most expensive electric bike kits around (due to high power, regen and battery size)
- Official Site: http://ridebionx.com/media/photos/bionx-d-series-2014/
- Official FAQ: http://ridebionx.com/services/faq-ebike/
- More Pictures: https://goo.gl/photos/gZmUogxqzqQyj6xL6