Less drag, more freewheeling fun
The Rotor R-Volver rear hub features some genuinely innovative design and simple construction to minimise friction.
Rotor’s new R-VOLVER hub system promises to reduce the friction within your drivetrain. Now this might not sound that significant, but by effectively disengaging the freehub drive mechanism while the rider isn’t pedalling the hub should theoretically spin for longer.
Simply put you should be able to go roll further for no extra effort. Who doesn’t like the sound of that?
How does the Rotor R-Volver hub work?
The system is actually pretty simple. Specially shaped pawls located on the freehub body engage with a floating ratchet ring.
Put pressure on the pedals and the pawls engage with the toothed ring to provide drivetrain engagement. Stop pedalling and the unique shape of the pawl ‘pushes’ the ring away from the freehub to totally disengage the drivetrain.
You could think of it a bit like engaging the clutch pedal in a car. Press down and everything can freely spin about with no extra input. Release a clutch pedal and the engine drives forward.
As you can see from the short vid Rotor has produced the whole system is pretty simple. By doing away with connecting the ratchet ring to the hub shell Rotor has made the R-VOLVER lighter than many other similar hubs.
A Shimano compatible BOOST hub weighs in at approximately 238g (compared to a Hope Pro4 BOOST at 311g). The freehub body has multiple pawl recesses for either adding more pawls to enable quicker engagement or to rotate pawl location to increase the life of the freehub. The whole thing can be stripped using only a couple of hex keys.
Possible suspension benefits
Where the concept gets a little more interesting is when you consider suspension kinematics. Drivetrain friction and chain tension can drastically change the performance of some systems, pedal ‘kick-back’ being one such issue.
Whilst we need to test the hubs properly, the use of the hub and its ability to isolate drivetrain forces may lead to an improvement in the performance of a full suspension frame.
We have seen other companies experimenting with similar systems, such as Canyon Dis/Connect technology. Unlike this, the Rotor hub enables automatic engagement and disengagement without needing an external lever.
Rotor will be producing the R-VOLVER in BOOST and non-BOOST options, only the BOOST option is available with a SRAM XD driver. Rotor are also manufacturing a matching front hub in both widths.
UK availability should be from October. Prices were still to be finalised when we spoke to Rotor at Eurobike.