The NYX frame kit uses carbon fiber in the construction of the main frame battery compartment, and using this light and strong material makes this frame a rare and upscale product.
Eloi Fugere and Cedrick Baker
The NYX company is based in Drummondville, which is located in Quebec, Canada. The concept of an upscale electric bike frame kit using carbon fiber was finally put into action by the NYX company founders, Eloi Fugere and Cedrick Baker. Eloi remains as the head of NYX, but Cedrick has moved on to other ventures.
The ebike in the pic below is a snapshot of a typical NYX build. The frame “can” be used for a street ebike, but the vast majority are currently used for an off-road build, and this one uses knobbie tires that are mounted on very strong moped rims. This example is outfitted with high-end brakes, and a well-regarded fork-set.
The rear hubmotor is a common size, using a 205mm diameter stator. If you look close, you can see the radial aluminum fins that have been added to help the motor shed heat better, and…although you can’t see it, the inside of the motor has a sample of Ferro-Fluid in it to further improve the heat-shedding. Don’t let the mirror, headlight, and fenders fool you…this ebike is VERY illegal on city streets due to the “over the top” power level.
Several different controllers have been tried, and the Adaptto Max-E from Russia appears to be a NYX-builder favorite…just like the one shown here.
There are several frame-kits available that have a large “boxy” section in the frame in order to hold a large battery, such as the Qulbix, the Phasor, the Greyborg, and also the Vector (among others). You can always have a smaller battery inside in order to keep the ebike as light as possible, but…I immediately wondered…exactly how large of a battery could fit?
After some searching, I found a build that was using two rectangular blocks of cells that formed a 20S / 12P battery pack (240 cells in the 18650-format). The nominal (average) voltage of lithium 18650 cells is 3.7V, so 20 of them in series is a 74V system (It’s 82V when fully charged to our recommended maximum of 4.1V per cell).
Now that we know the voltage, the total power in watts is that number multiplied by the amps. The cell this builder chose is the highly-regarded Sony VTC4. Each cell has 2100-mAh of range, and a 12P pack results in a fairly large 25.2-Ah pack. Since this cell is factory rated at 15A per cell, a 12P pack also means it should easily produce peaks of (12P X 15A =) 180A!
74V X 180A = an eye-opening 13,000W
The NYX battery box is formed by bonding the two side halves together. That’s not just the most cost-effective way to make a box this size, it’s also a great way to make a very light structure that still has great performance. The heavy loads from a hard hit when taking big jumps will focus a lot of stress along the side-panels. If the battery access opening was on the side, then the removable cover would have to be strongly re-enforced to handle it, which would add weight.
The more consistent and rigid that the side-panels are…the less stress the top-panel feels.
Concentric Bottom Bracket and Pivot
There are actually two distinctive features of the NYX frame. After the eye-catching carbon fiber, the swingarm pivot is concentric (having the same centers) with the bottom bracket.
Most off-road ebikes have the swingarm pivot located nearby the bottom bracket, usually a little above it, to reduce a reaction called “squat” when high power is applied. However, since the swingarm pivot and the Bottom Bracket centers are in different locations, the chain path must change as the suspension moves up and down, sometimes resulting in a reaction called “chain growth”. Even in ebikes that don’t have a derailleur (such as a single speed system), the chain is usually sized a little longer, and then the varying chain-run length will have it’s slack taken-up with a “chain tensioner”
The Greyborg also uses a concentric bottom bracket, so…both of these frames never experience any chain growth. This means that…as soon as you move the wheel axle back enough to tension the chain, you can just set it and forget it…with no slack-tensioner needed.
Another ebike that is known for this feature is the Stealth Bomber.
In the pic below, our friend Luke chose a belt instead of a chain, which runs very quietly. This is one of the benefits of a hubmotor, even in a time when so many are switching their off-road builds to a mid-drive. A direct drive hubmotor that is driven by a sine-wave controller, and then combined with a belt-drive from the pedals? That is about as quiet when running as physics will allow. The loudest noise will be the sound of the tires rolling across the ground.
He also added a top-of-the-line Schlumpf drive crank-set. This allows him to use a smaller pulley in order to retain a good amount of ground clearance, while still being able to pedal along at the higher speeds, due to its 2.5:1 gearing.
If the picture above looks a little “off”…it might be because of the proportions of the motor. It is a QS 273, which is extra large, and extra powerful. A common 205mm diameter stator is more than enough for my wildest dreams, but…Luke wanted just a little bit more.
A NYX in the Garden
Here are a few pics of a NYX build that show how pretty it is, when you finally get up close. Pics courtesy of ES member ‘Grunt’.
The controller dash panel is from a Russian “Adaptto Max-E”.
Below, you can see that, rather than make the battery box shorter and fatter to have more battery space, NYX opted to make it narrow and taller. The interior dimensions easily fit 18650 cells on their sides, laying left to right.
Dr Bass, 2WD, and MXUS
Dr Bass has been a famous ebike hot-rodder for years, and he was an early promoter of high-performance ebikes. Since he is from Canada, he was one of the first early adopters of building with a NYX frame, except…he went in a slightly different direction.
If you look closely, you will see that his NYX below is using street tires, and that is the main clue to why he went to 2WD. The desire to make a 2WD ebike for off-road is an obvious choice, but for the street?…Dr Bass knew from “hands on” experience that when you build something with VERY high power, you can quickly reach a point where traction becomes the limiting factor. Doing a burnout with the rear tire can be fun…maybe a few times, but…after while you begin to realize that spinning your rear tire…is not the same as accelerating.
Dr Bass has been improving his 1/4-mile acceleration times with each upgrade. Although I normally recommend a geared hubmotor for the front motor of a 2WD build, Dr Bass knew he was going to be pumping a lot of heat into his motors, and he decided to use large direct drive hubmotors from MXUS on both axles, along with drilling ventilation holes into the sideplates to let the heat out.
Dr Bass’s 2WD NYX ebike doesn’t have a lot of range or a heavy battery…he only needs it to travel 1/4-mile at a time (*wink).
For more information about NYX…
And…if you want a pre-built ebike instead of building up your own, NYX now has several turn-key ebike models available
Written by Ron/spinningmagnets, May 2018