A “Rocker Plate” is a device used to add one or more motion (degree of freedom) to an otherwise rigid bike & trainer combo. Most designs sit on the floor, and then support the bike, trainer and rider on top of them. The rocker plate has mechanisms (simple or complex) that allow motion for the rigid trainer bike and rider combo.
Why use a Rocker Plate with your Rigid Trainer?
Comfort In & Out of the Saddle
The small side movement of the saddle, even when seated, helps relieve pressure on the sit bones and soft tissue.
The added rocking motion encourages standing because it feels more free than rigid trainers which can lead to more frequent breaks between seated efforts.
When you have a bike that is perfectly comfortable outside, and then leads to problems when ridden inside, I feel it is important to look at what is different. When you do, there are two key differences.
Lack of wind resistance on the body riding inside. That is a difference that I find because you end up with slightly more weight on the hands and arms, because you don’t have the wind pushing your upper body back.
To compensate for that, I recommend that people raise the front axle about 1"-2" [25mm-50mm] higher than the rear axle. This shifts the weight slightly back onto the saddle and off the hands and arms.
A bike mounted into a typical trainer ends up being very fixed and rigid in position. This can lead to excessive loading on the sit bones on the saddle because there is no shift in the demand on the muscles and tissue around them.
The non-equipment solution is to introduce standing breaks into your riding. Anything from every 5 to 10 minutes is common. These breaks can be for anything from 10 seconds or pedal strokes, up to minutes at a time if desired (for saddle relief directly or other training reasons).
The equipment solution I recommend is adding motion to the trainer setup. The Kinetic Rock and Roll trainer was my inspiration. But I made a simple double plate stand with a hinge that allowed me to mount a rigid trainer and turn it into a rocking trainer. These are called “Rocker Plates”.
Core & Upper Body Use
With softer leveling spring settings, it requires more engagement from the core and upper body to ride level and maintain a smooth pedal stroke.
This is true for seated and standing efforts, when compared to rigid trainers.
More Standing Pedaling Motion Freedom
Standing pedaling on a rigid trainer is awkward and not at all like riding a bike outside.
On a Rocker Plate, the bike & trainer are more free to lean to both sides. This can allow the rider to move in ways that are less awkward than on a rigid trainer.
Frame Stress
Unproven by testing and data, but Rocker Plates are likely to reduce stress on frame members since they allow float and likely reduced side-loading to the frame members.
Question - I ride a Neo, and it “rocks a little”, but I still have significant saddle issues, especially in classes that have long steady intervals. I’ve been through 4 saddles that all work fine outdoors but are torture devices indoors. It’s bad enough that I’d rather do a class like Spanish Needle than a class like Petit.
I wonder if rocking the trainer will introduce additional stress to flywheel bearing. Kickr has a heavy fast spinning flywheel, which makes a great gyroscope. Gyroscopes don’t like being tilted sideways.
I have a Kinetic Rock and Roll trainer and really like the sideways movement that gives. It certainly provides a bit more saddle comfort when doing long steady state intervals and longer turbo sessions and the pedalling motion feels much more natural when doing out of the saddle drills. It (and rocker plates more generally) doesn’t give you the same motion as you get when out of on the road - it’s of a different nature - but it feels more natural than the locked in position of most turbo trainers. It’s just a pity that it’s such a beast of a turbo trainer in terms of its footprint
We have plenty of people with Neo’s that have added a rocker plate. They notice a real improvement in motion and usually in comfort as a result. The flex built into the Neo is better than nothing, but it is pretty minimal when compared to a more functional rocker plate.
The fact that a RP allows that subtle shift from side to side, it replicates what we experience on the road. It changes the loading on the sit bones and related tissue with every bit of motion. I find it removes that tendency to grind those parts with no change in loading.
Overall, saddle comfort is the driving reason people build a rocker plate. Most of the people I have seen add one, say that the RP has noticeably increase the seated comfort on the bike, especially when seated. Very few say there is no difference.
Doubtful. The motion is minimal when you look at where the trainer sits and the total displacement that it experiences.
At max, my rocker plate is 7* off-center. It spends much more time in the 1-3* range which is what I consider to be negligible. AFAIC, it is a non-issue.
That and the desire to use the trainer I already had at the time (Kinetic Road Machine) is one of the reasons I may my first rocker. There is no need for the width they made, IMHO. Maybe it is there to prevent those larger riders and/or those with questionable balance, but I have not had issues with my 32" wide footprint.
While I’m really tempted to build something, or just get the Rockr, I’m waiting for CycleOps…this design is the most promising I’ve seen. The forward/back and side/side motion seems to be very natural from the videos I’ve seen…I wish they would announce it already…
I use sqlab saddles ( SQlab GmbH Online Shop | SQlab - Ergonomic bike equipment, award winner, ) and their ”active” saddle technology and find this helps greatly with hours in the saddle on a rigid trainer. I definitely notice the benefits when riding inside. Likely more epensive than setting up a rocker plate like @mcneese.chad and others but it can follow me outside.
I’m looking at building a rocker plate. I’ve watched Chad’s video on the plywood version but I was thinking of building something a little more robust with a shaft and pillow bearings. I looked on the Facebook rocker plate group and saw several examples but didn’t really see any DIY guides or materials lists. Anyone know of any?
Pretty sure there are some ‘files’ on the FB group page.
Loads of pictures too so if you’re technically minded you can reverse engineer something.
I’ve picked up pillow bearings, rod, tennis balls and some (to be decided on my day off tomorrow) MDF/Ply.
There’s more than one way to skin a cat with people opting for rubber bushing etc over bearings & rod. Equally you can use a combination of balls, bushings, inner tubes etc to give varying ‘rock’ resistance and feel.
(Something to consider is where the central mass of your trainer lies and whether you will need to counter this with weight or your positioning of the rocker stops (balls, bushes etc))
