Fox Manufacturing facility has filed a patent titled “Suspension Enhancing Hub and Rear Derailleur Meeting”, outlining two separate however associated innovations designed to get rid of the destructive results that chain stress exerts upon a bicycle’s rear suspension and trip really feel.
A rear derailleur with an electronically actuated clutch mechanism offers with chain stress between the chainring and the derailleur, whereas an computerized digital decoupling hub meeting offers with chain stress created between the chainring and the cassette. Within the patent, each parts are described as being managed by sensors detecting vital details about the trip, equivalent to gradient, pitch of the bike, and suspension motion, whereas the potential for an “over-ride” can also be described that might enable the rider on-the-fly management over the conduct of the parts.
It’s a “no-comment” from Fox on this one, however we’ll definitely be maintaining an eye fixed out for these parts come the opening spherical of the World Cup DH in Lenzerheide this Might.
Fox Suspension Enhancing Hub and Derailleur Meeting: Context
Earlier than digging down into the main points of the 2 innovations described in Fox Manufacturing facility’s patent, it’s vital to debate why both could also be vital within the first place. So, you’ve all seen Aaron Gwin’s 2015 World Cup DH Run at Leogang, proper? If not, go watch that then come again and skim on.
Certainly, Aaron took the win regardless of dropping his chain as he cranked out of the beginning gate. Not to remove from Aaron’s achievement that day, however it’s no secret that depending on the actual linkage design, the efficacy of a full suspension mountain bike’s rear suspension stands to learn from the absence of a series.
Within the presence of a series, pedal kickback will be skilled because of rising rear-center size, notably on bikes the place the principle pivot is just not concentric to the BB; i.e. most of them. Concurrently, alongside the decrease chainline if you’ll, resistance is obtainable up by the rear derailleur because it extends in the course of the suspension’s compression section, notably if that derailleur’s chain tensioning facet has a clutch mechanism damping motion of the cage. Each of those phenomena are largely thought-about undesirable traits, notably on this planet of downhill mountain biking the place suspension efficiency is paramount.
The Fox Manufacturing facility patent mentioned herein describes two distinct innovations seeking to clear up the aforementioned points led to by rear-center size adjustments occurring because the suspension compresses and rebounds.
Fox’s Digital Robotically Decoupling Hub Meeting
One in every of these parts is an “digital mechanically decoupling hub meeting”. A set of pawls are housed inside the hub, from the place they are often compelled to selectively interact or disengage with ratchet enamel housed on the freehub physique (or cassette physique) such that when the rider pedals, pressure is transmitted to the hub shell to drive rotation of the rear wheel. That uncommon, kind of inverted association seems to be essential to the center of this invention; the digital management of pawl engagement.
Whereas pawls are often spring loaded, right here Fox describes conditions (or embodiments) the place the engagement state of the pawls is set by an electromagnetic circuit managed by the inputs of a sensor or sensors distributed concerning the bike.
The patent doc states, “In a single embodiment, digital mechanically decoupling hub meeting makes use of magnets in every of the pawls with inductors/electromagnets above it and managed by a controller contained in the hub shell NDS. When not pedaling the pawls could be disengaged by the inductors/electromagnets turning on or flipping polarity to draw the pawls upwards away from the ratchet ring on the cassette physique. When pedaling the inductors/electromagnets could be turned off and the magnets of pawls interested in the ferrous ratchet ring (much less vitality utilization). Or the polarity of the inductors/electromagnets may very well be flipped to repel the pawls away, forcing them towards the ratchet ring”.
It goes on to explain the potential advantages of getting real-time management over engagement and disengagement.
“the digital mechanically decoupling hub meeting may have a virtually infinite quantity of computerized engagement and disengagement, in real-time, and all through the trip. As such, the rider would have the entire regular suspension articulation throughout a lot of the trip and when completely different ranges of violent suspension articulation occasions occurred, the chain strain by way of the digital mechanically decoupling hub meeting could be decreased to make sure full suspension articulation whereas additionally minimizing the chance for a violent suggestions by the pedals that may be transferred to the rider”.
Fox’s Digital Disengageable Rear Derailleur Meeting
The second invention described inside the patent is an electronically disengageable rear derailleur meeting. Figures printed as a part of the patent depict a derailleur with a mounting part, a parallelogram part for shifting by sprockets of the cassette, and a P-Knuckle housing a clutch mechanism that’s coupled to a short-cage with an higher and decrease pulley wheel.
The attention-grabbing parts of this derailleur lie inside the P-Knuckle. The Fox patent describes the P-Knuckle as housing a motor and kit, a spring (or solenoid) housing, a linear solenoid, a torsional energy spring, a P-Knuckle clutch plate, at the least one thrust bearing, and a P-Knuckle cowl.
The “digital disengageable” bit refers back to the articulation of the derailleur cage concerning the P-Knuckle. It appears as if the electronically operated clutch mechanism inside the derailleur will be selectively switched on or off, as determined by a controller processing info from varied sensors on the bike.
“In a single embodiment, disengageable derailleur meeting stays engaged beneath regular chain keep size adjustments equivalent to suspension articulation as a consequence of pedaling, regular suspension journey points, and the like. Nevertheless, when a major suspension occasion happens, e.g., hitting a big bump inflicting a big, fast articulation of the suspension P-Knuckle meeting is not going to present important damping in the course of the chain size extension”.
It makes numerous sense to reduce the results of chain stress throughout suspension compression, to permit the suspension to work its magic over tough terrain. Nevertheless, the clutch on a derailleur is there for good motive; to cease the chain slack from rising to some extent the place the chain is ready to leap off the chainring. That is, after all, thought-about within the Fox patent too.
“Sustaining chain stress is vital to keep up chain retention such that the chain doesn’t bounce off a series ring. Nevertheless, the disclosed expertise selectively engages and disengages the cage meeting from the P-Knuckle, such that the strain on the chain is relieved (as a result of disengagement) when the chain development is rising. Furthermore, (as a result of re-engagement traits of the cage meeting with the P-Knuckle) stress is maintained when the chain development is decreased or is not rising”.
As any model would, Fox is protecting many, many bases with this patent, rising its scope to incorporate a model (or embodiment) of the disengageable derailleur meeting that is ready to make use of the “wave dynamics” of the chain itself to handle frictional disengagement and re-engagement.
It reads, “disengageable derailleur meeting can actively, mechanically, and regularly modify the place of P-Knuckle meeting with respect to the place of cage meeting based mostly on suspension place and gearing such that the system will at all times have the right amount of chain paid out. This might reduce chain slap and will get rid of load on the entire suspension system”.
The place is Fox going with this?
We contacted Fox to inquire about their meant use of this expertise. As anticipated, “no-comment” was the reply. Thus, we’re left to hypothesize.
An apparent software for this expertise is in Downhill and Enduro Mountain Biking, the place the scope for pedal suggestions and chain stress to negatively impression a rider’s efficiency is comparatively excessive. Certainly, a number of makes an attempt have been made over time to cut back pedal kickback. For instance, OChain’s Energetic Spider has develop into fashionable on the World Cup DH Circuit; it permits for some dissociation of the chainring and cranks such that the cranks aren’t compelled to rotate rearward throughout pedal kickback occasions, permitting the rider to keep up a “pedals stage” place.
I digress. It’s attention-grabbing to notice that whereas a lot of this patent doc particulars the usage of sensors and processors to regulate the working state of the decoupling hub meeting and disengageable rear derailleur, the potential for an “over-ride” can also be talked about. This means a chance that the 2 parts may additionally conceivably be managed by a distant operable on-the-fly by the rider if mounted on the handlebar.
One can think about a state of affairs whereby the rider would be capable of change between two pre-set drivetrain states, depending on what sort of terrain they have been about to cost into. Come the beginning of the 2023 World Cup DH Season, we shall be maintaining an eye fixed out for something of the type.
In the end, it appears logical that management of the digital mechanically decoupling hub meeting and digital disengageable rear derailleur meeting described in Fox Manufacturing facility’s patent could be built-in into the Fox Dwell Valve ecosystem whereby suspension damping is mechanically and electronically adjusted in real-time.
Provided that these suspension parts home accelerometers and different sensors monitoring the bike’s state, it isn’t too wild to recommend that those self same sensors may ship info to a processor to additionally make choices on the suitable state of operation for the decoupling hub meeting and disengageable derailleur meeting. In spite of everything, the Fox Dwell Valve digital compression damping system is being requested to observe the terrain 1000x per second and to make changes based mostly on that info inside 3 milliseconds. That’s 100 instances quicker than the blink of an eye fixed!
Lastly, provided that present suspension linkage designs should take into consideration the presence of chain stress, it’s doable that profitable implementation of the Fox Suspension Enhancing Hub and Derailleur Meeting or parts to that impact may have big implications for the way body engineers design full suspension mountain bikes in future.
As ever, you’ll have extra info on Fox’s Suspension Enhancing Hub and Derailleur Meeting once we do!
