Different bikes need different hubs and bearings to optimize performance. We’ve talked about how MTB hub design affects performance, and the design features of eBike hubs, but why do you need specialized eMTB hubs for bikes with integrated motors? The answer lies in the speed at which the power assistance from the motor kicks in and increases acceleration. This puts a lot more strain on the hub components, and that’s why Revv manufactures a specialized hub just for eMTB use.
How do eMTBs crank up the torque?
When you go faster on a bike the increase in forces acting on the hub is not linear, the rotational energy of the bicycle wheel is a form of kinetic energy that obeys a square law. This means that the forces on the hub and hub components transferred through the pedals don’t just add up as you pedal more quickly, they multiply.
Changes in cycling cadence, or the speed at which you turn the pedals, affect torque transfer to the hubs, but because the power a person can put through the pedals is normally not more than 300W, it’s not too difficult to design a hub that can handle the torque generated by even a highly trained cyclist. The problem comes when you add the energy of an electric motor to the setup.
Why is delivering more power a problem for eMTB hubs?
Even the most basic electric motors fitted to an eMTB generate around 250W of power, with many able to deliver 1000W of peak power. Electric motors are able to deliver this power instantly, which adds to the shock loading on all the components in the drive train when you accelerate your eMTB using motorized power assistance.
With an eMTB, you want a hub that can immediately absorb and transfer the increase in power when accelerating, and also disconnect just as fast for smooth freewheeling. The Revv MX series of eMTB and MTB hubs are custom designed to deliver fast take up without complaint even with the highest torque electric motors, without compromising on freewheeling performance.
How do Revv eMTB hubs shoulder the load?
When you design a high performance eMTB hub it has to have features that meet the needs of the rider. Like all MTBs, the eMTB has to be robust and easy to maintain, especially if you’re planning to head out into the wild. The added torque demands of eMTBs requires a more robust ratchet pawl system. Revv hubs have a patented four pawl design to absorb the increased stresses without the risk of breakages, even when paired with the most powerful eBike motors.
- Robust steel construction
- Patented four pawl, responsive rear hub SRS ratchet system
- Standard dimensions match modern bike frames
- J-bend spokes for easy maintenance and adjustment
You’ll appreciate the robust steel construction, even stronger than the forged aluminum alloy we use in our other high performance hubs, which increases robustness and reliability in the harsh conditions of rough off-road trails.
J-bend spokes are easier to fit, adjust, and replace than straight spokes, which is why they are a favorite of MTB and eMTB riders everywhere. The reduction in wind resistance of straight pull spokes is not a significant advantage at the slower speeds experienced in MTB riding. 32 spoke configuration adds strength and resilience to the wheel to get you through those tough tracks.
Experience the high quality and performance of Revv eMTB hubs
At Revv, we don’t believe in compromise. If you want high performance and exceptional quality that’s what we deliver with our robust, reliable, smooth-operating eMTB hubs. Not only do we offer performance-optimized designs from the ground up, we build them to exceptional quality standards, with comprehensive quality checks at every production stage. Perfect for high performance mid-drive eBikes with a crank-mounted motor, our eMTB hubs will make good use of all the torque you can throw at them!
What are the quality control stages for eMTB hub manufacturing
- Specification Checks For Incoming Materials
- Full Dimension Inspections
- Key Dimension Measurements
- Reference Piece Checking During Assembly
- Hub Cylindrical Dimensions & Ratchet Torque Measurements
- Finished Product Quality Checking
The patented Revv SRS (Spring Ratchet System) eMTB rear hub design features balanced springs and a four pawl ratchet to combine high strength with the direct road feel that today’s cyclists demand from their bikes. We have tested our hub designs on the road for more than 8,000km without failures, testament to our dedication to delivering the optimal hub performance for any cycling demands. Contact us today to discover how Revv hubs can complement the excellence of your eMTB designs.
