The new Flux Primo is a bike that caught our eye as soon as it was teased back in 2022. Needless to say, we were honored to be the first to go to Slovenia and test this impressive machine. Well, technically this bike we’re testing is Flux’s development mule. The development mule means that Flux is using this bike to test ride characteristics and develop software before moving on to a more refined pre-production model. We really enjoy to see the bike in these early stages though, as it makes it very fun to compare to the production version when it comes, but more on that later.
Flux primarily identifies itself as a powertrain company, focusing on innovating in the areas that matter most to them: the battery and drivetrain. While they also very much care about the chassis, they believe that frame geometry and flex characteristics have already been mostly solved and are therefore less of a challenge to conquer.
This production mule bike is equipped with a massive 450 volt 7kWh battery, which generates approximately 80 horsepower. Knock knock, Stark Varg, you have a new neighbor. It features an aluminum chassis, currently utilizing a KYB SSS fork and an Ohlins TTX shock, as well as Brembo brakes and a unique virtual clutch/regen lever.
Flux Primo Power
Now, let’s talk about power. The claimed 80 horsepower on the Primo is as insane as it is surprisingly subdued. The power feels abundant, but it’s also extremely mellow for the first half of the throttle. There is an obvious threshold though, and it’s right around half throttle. At half throttle and beyond, the Primo absolutely screams. This balance reminds me of an electric version of a 300 2-stroke like the KTM XC-W. It rolls on slow and has kind of a mild luggable feel down low, but once you wake it up, it quickly reminds you that it is a ferocious machine, with more than enough ponies to humble you.
Virtual Clutch / Regenerative Braking Lever
One of the most pleasant surprises for me was the virtual clutch/regenerative braking lever. When accelerating, it acts as a digital clutch, reducing power while you’re on the throttle. Once you release the throttle, it seamlessly transitions into regenerative braking, helping to slow the bike down using the motor. Though I didn’t have much use for a clutch in the riding environment, I found myself using the regen lever as a so-called third brake to reduce speed. It quickly became a standout attribute of the bike, especially in right-hand turns where I preferred to keep my right foot neutral on the pegs. In fact, in some cases, I was able to forgo the brakes entirely and rely solely on the regen lever to decelerate. Now I wish every bike in our fleet had one of these regen levers!
Chassis & Suspension
Moving on to the chassis, I was surprised by how similar it felt to some gas-powered bikes I’ve ridden in the past. I won’t call it directly, but if you could envision the combination of these two specific bike colors I’m thinking of, it would result in the color purple. To me, the bike feels stable and confident, although the inverse of that is that it leans towards not being a super quick turning bike. It took me a short while to get used to this, but I believe Blue Cru riders would feel right at home. Once I became familiar with the steering feeling, I truly appreciated how predictable the bike felt.
In terms of suspension, the setup on this specific bike was a bit oversprung and overvalved for my weight and this terrain. However, the KYB SSS fork performed exactly as expected: it was awesome. Being that it was on the firm side, the harder I pushed it, the better it responded. Although the Ohlins shock may be replaced by KYB for the production model, the bike felt well-balanced and inspired confidence.
How Far Can the Primo Go?
Now, let’s address the battery. While I couldn’t accurately gauge the range during my ride, I estimate that this current model is on par with a Stark Varg, if not better. However, I cannot fully verify this at the moment. Flux did mention that the next prototype model is expected to have a larger battery capacity of just under 8kWh, but at the same weight. If achieved, this would be quite impressive, but we’ll have to wait and see.
Supercharging the Flux Primo?
Next, let’s talk about charging. This aspect truly impressed me. Flux brought along their in-house Monolith supercharger, which requires 3-phase power and Flux claims will charge the 7kWh battery pack from 10% to 80% in just 25 minutes. We put this claim to the test, plugging the bike in after I had depleted the battery to 14%. In approximately 15 minutes, the battery charged back up to an impressive 62%. This was plenty of battery to continue riding, the bigger question was if I had enough energy to match the Primo. It’s unclear if the Monolith charger will be available for sale with the Primo, but regardless, it opened my eyes to the potential of quick charging for high-voltage bikes.
Flux Primo Price and Production Target
The Primo is a highly promising offering from Flux. While it still has a way to go before becoming a true production bike, Flux aims to have a production model available by the end of 2024, with deliveries starting in the 4th quarter of 2025. The target price is $13,000 USD, and a refundable reservation of 50 euros locks in a price of $12,000 USD.
In the meantime, we’ll be keeping a close eye on the progress of Flux and reporting on their victories.
