In this article, we’ll be discussing a Suspension System by Ohlins, US publication 20210179227. The publication date is June 17th, 2021 and the filing date is Jan 12, 2021. This has not been granted yet. This is a wordy article with no cool pictures.
Brief Summary (tl;dr)
11/24/21 edit: I’m listening to this podcast with the inventor of Live Valve, and he’s saying that Live Valve also has some type of delay/event metric associated with a valve change. So, this next paragraph may be off a little bit. Now I’m really curious as to if Ohlins can get this through and if it’s the same as Fox’s system.
Ohlins have created their own spin on an active suspension system. The best way to describe this is to compare it with the Live Valve system. Live Valve constantly adjusts the suspension based on each bit of sensed information (bump, pedal, etc.) in an attempt to optimize each immediate situation.
Alternatively, this Ohlins system takes sensed information and maintains the suspension setup in the same configuration for at least 0.1s. So, rather than constant adjustments, Ohlins want to maintain a setup for a longer amount of time. They say this is much better for battery life, since the system isn’t constantly adjusting, and the performance is only negligibly worse.
Intro
Ohlins are also stepping into the realm of active bike suspension systems. I know we all seem to have an opinion on what these will do and the ramifications, but this document only strengthens the argument that these systems are coming to mountain bikes, whether we like it or not.
In this system, rather than constantly adjusting the fluid pathways a zillions times per second, this system will detect how the rider is riding, and what they’re riding on. It will adjust the suspension and hold that suspension setup for a longer amount of time. So, it’s not instant for every single input. For example, when the bike detects you’re climbing, the bike will stay in a static climbing configuration, which saves battery power because the suspension isn’t constantly adjusting itself.
This document explains less about the actual fork/shock components and more about this new system. In particular, this system attempts to create an active suspension system with lower power consumption. They don’t say how they’ll do calculations or specifics about what the suspension will actually do, but they do have a pretty good explanation from a high level.
Why
Ohlins states that they want to provide a plethora of ride characteristics without the rider having to manually adjust the suspension. They do, however, mention a lockout quite a few times. It appears as though this will, primarily, be used for automatic lock and unlock situations. Although, Ohlins say:
Also, having two extreme positions (fully open or fully locked), does not always provide the required amount of versatility and performance. In certain situations, the rider would for example benefit from suspension adjustments lying somewhere between the two extreme positions.
So, it sounds like they also want to provide some level of automatic suspension adjustment. Ultimately, though, they want to provide a simpler active system that improves battery life.
This [invention] has been found to amount to a very good compromise between suspension performance and battery life which none of the previously known systems have been capable of.
What
First, let’s define the components:
100 is the suspension control system. This is just a generalized term for the entire active suspension system, including sensors, controllers, etc., not any particular component.
200 is the interface on the handlebars. This is where the rider would interact with the suspension system and is used to control the different ride selections. The ride selections would be things like uphill, downhill, etc. So, the rider picks a setting and sends the setting information to the control unit.
300 is the control unit. This is what makes the decisions based on the sensor input, and sends the info to the suspension. It’s the brain. Every active system needs this.
400 is the ‘sensor arrangement’. That’s just a funny way of noting the sensors around the bike. Ohlins says the sensors can be an Inertial Measurement Unit (IMU). Every active system needs this.
It has, however, surprisingly been determined by the applicant that for most situations it is fully adequate to use a single Inertial Measurement Unit (IMU) arranged at the main frame of the bicycle.
500 are the actuators. There’s one in the seatpost, shock, and fork. The actuators are typically little motors or something moveable to open and close fluid or adjust some kind of shock parameter. For example, Fox’s patents say they’re using a linear voice coil in their Live Valve system. Ohlins says their actuators can be a“…stepper motor, solenoid, piezo motor or other suitable machinery”. Every active system needs this.
The lower power consumption comes from the fact that the actuators are capable of maintaining their position in a non-energized state. This means the battery doesn’t need to be used to maintain the position of the actuator. So, the controller will tell the actuator what to do, then there is no more power to be used to keep the suspension in whatever state it’s in. Here’s a line that states this concisely.
…the actuator is only energized during a change of setting of the front suspension and/or the rear suspension and wherein said actuator is arranged to maintain its position in a non-energized state.
How
First, we’re going to start with a high-level view of this system. Ohlins says they can determine ‘ride states’, ‘ride modes’, and duration (time) to calculate an ‘event’. The ride modes are things such as ascending, terrain, airtime, etc. The system will allow the rider to select a type of ride they’re doing, which affects how the system reacts to the sensed information.
Typical user selections can be ride types such as “Downhill”, “Cross-country”, “Commuting” etc. etc. Event types may also be selected and can comprise e.g. “Race”, “Race practice”, “Training” etc. etc.
Ride Modes:
Ascents and descents can be detected and used in the calculations:
In order to make optimal suspension settings, ascent can be subdivided into low; moderate; and steep ascents. Similarly, establishing that a vehicle is descending is equally important and descending can also be subdivided into low, moderate and steep.
The system can determine how technical the ground is:
It is possible to differentiate on exactly how technical the ground is in a suitable number of sublevels, i.e. non-technical; less technical; technical; very technical; extremely technical, as required and preferred.
The system can also tell if you’re in the air:
It is also possible to add another sub-category, namely that there is no ground at all on which the bicycle is riding, meaning that the bicycle for example has hit a jump and is currently in the air. When this mode is detected, the system will prepare the bicycle for the often rather heavy impact that occurs when the bicycle hits the ground again.
Interestingly, the system also has impact modes. So, the system can adjust the suspension based on the assumed impact with the ground after a sick jump:
The impact as such is also a mode that the system of the present disclosure can detect and use when setting up the suspension. It is possible to for example differentiate between no impact; low impact; moderate impact; high impact, and; extreme impact.
Speed, acceleration, gear, coasting, and cadence can be detected:
Speed can also be monitored and used as a ride mode… The acceleration of the bicycle is also measured… front and/or rear gear selection can be monitored and used as a ride mode… it is possible with the present disclosure to determine whether the rider is coasting, i.e. not pedaling at all or if, pedaling takes place, if this is done at an easy, medium or high intensity and at which cadence this is done.
Here’s an interesting line about a very specific situation this system can detect and compensate for. Basically, it can keep you from fucking up your teeth because you can’t jump.
This [system] makes it e.g. possible to determine the position of the bicycle and take necessary action. For example, a forward tilted bike mid-air will probably require a rather stiff front fork setup to accommodate an upcoming front wheel landing.
Rider position can be determined for center-of-gravity (CoG) calculations:
…the rider position, i.e. sitting down or standing up can be determined and used in the suspension set up of the present disclosure. The rider’s position affects the center of gravity of the vehicle and as such it also affects the required suspension set up.
Seat position can also be determined and used in CoG calculations:
The seat position, if using an adjustable seat post, can also be monitored. This since it will affect center of gravity and it is also possible to dedicate certain suspension setups to the different seat positions. For example, a maximally lowered seat position is often used for aggressive downhill riding and as such suitable suspension setup can be coupled to such seat position.
Ride State:
The controller takes all of these ride modes and combines them into a ‘ride state’. An example of a ride state is a ‘…pedaling hard on a moderately steep but technical decent’. Notice how the modes are the pedaling, steepness, and technical ground. All of these are combined to determine the ride state. There are a shit load of different ride states, which (I think) would be determined using a matrix or a lookup table.
So, the bike now has a bunch of ride modes and a determined ride state. Now what? Well, the system then assigns a suspension setup based on the ride state. Again, I assume the suspension setup is applied based on a lookup table (could be wrong). Referencing the example above, the system assigns a suspension setup if you’re about to endo over a jump.
Event:
Lastly, the system takes the ride state, the suspension setup, and determines a duration (time) to define an ‘event’. The duration is how long the event will be maintained. Ohlins says the duration of the can be as short as 0.1s. This means the suspension will maintain a position for at least 0.1s.
The system then restarts the process all over again. This should happen a shit-load of times every time you’re riding, without you ever having to adjust the bike yourself.
At the end of each event, the control unit starts from the beginning again by assessing sensor input, user selections and defines again a ride state and a duration in time, thus creating a new event.
Conclusion
So, this is a kind-of-active system. The more I think about this one, the more I like it. Honestly, the Live Valve system is still the correct answer, though it is much more difficult to figure out. This Ohlins system is simpler and will probably work well. Here’s an example scenario I’ve come up with that you may understand:
11/24/21 edit: I’m listening to this podcast with the inventor of Live Valve, and he’s saying that Live Valve also has some type of delay/event metric associated with a valve change. So, this next paragraph may be off a little bit. Now I’m really curious as to if Ohlins can get this through and if it’s the same as Fox’s system.
With the Live Valve system, the suspension will continually and instantly react to each bump in a rock garden. As a result, the fluid paths are constantly adjusted for each immediate instance of each bump. In this Ohlins system, the bike will determine an ideal scenario for a rock garden and hold the suspension in that state until the rock garden is done. It can even do this for climbing and impacts after sick-ass jumps.
…it has surprisingly been established that even though the system of the present disclosure does not constantly react to the current ride situation, which may be seen as the way to go when creating an active suspension system, the performance, both perceived and measured, of the suspension does not suffer, or at least only to a negligible amount, from this creation of events having a minimum duration in time.
So, this system appears to be fluid, but performance restricted. Ohlins has compromised overall active suspension performance for battery life, and there is probably a market for exactly that. They do say that this system doesn’t compromise that much, but it does compromise. Either way, I love seeing what Ohlins is cookin’ up. This is a creative solution that may offer most of the current active suspension performance, while also being more ridable due to the fact that the suspension isn’t constantly adjusted.
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