The fork mount is a challenge for me, My trainer is shared between myself and my wife and having to reposition the fork mount and adapt for her would be a barrier to training. where as the wheel on a lazy susan would just be as it is now, just on top of a platform.
That’s a limit, because I think you may need more “connection” between the bike and rocker if you really want steering input to have a real impact on leaning.
I do have a concept that I have never made, but can share with you if you want to be a test pilot
If the front wheel platform didn’t rock, maybe that would force more ‘connection’ on the rocker/trainer side of things? I’m all ears, I can’t promise it will get build though.
Imagine a rear only rocker plate, with the front wheel on a turntable, allowing the wheel to turn both directions.
Then, locked to the front riser that does not move, imagine a vertical fork sticking up along side the front wheel, about mid way between the front axle and the front of the wheel.
- This fork might have some foam on it, that is meant to allow wheel lean a bit as pure lean, but also twist the wheel within the gap.
Idea here being a loose but connected way to convert steering input into leaning action at the frame.
Here is a horrible quick example sketch.
the red is the vertical forks, the blue is the turntable. The red forks extend up past the lower part of the tire, and only really need to be as high as the tire contact.
Essentially, I am trying to turn the wheel into a lean input device, buy “pushing” against the fork to create a leaning control. Imagine having a friend stand in front, with their legs around the tire, then turn the wheel to control the lean.
Does that make sense?
That makes total sense, Need the wheel to push against something to be able to force the rear to tilt. This is really taking me down a rabbit hole I had no intention of going down! LOL
Ha, well let me know if you got that route. I have no idea if it will even work, but I always wanted to try (even before I got my E-Flex). Now I see how much having some steering controlled lean can add, I think the concept is worth a test at least.
Key will be the right placement of the tire contact (height and distance from axle) to the amount of lean in put per steering angle. I also think some level of “flex” is beneficial vs 100% hard connection.
Good luck and have fun with whatever direction you head.
Great start! Looking forward to learning more.
Has anyone actually tested the speculated reduced frame stress with a rocker plate? It indeed make sense that allowing a few degrees of lateral movement would reduce the stress on at the bottom bracket and seat stays. However, it would be good to have more than intuition to verify this. Too me it seem a little strange that Saris and Kinect haven’t marketed this aspect of their products, if true.
Perhaps an cyclist engineer with CAD/SimScale experience can do some FEA? Too bad that I’m just a mere data scientist or I would do it myself.
Just speculation at this point, AFAIK. I’ve seen no data or testing shared publicly.
I’m no engineer, just a mechanical designer with enough training to be dangerous. I’ve discussed it with a few engineers at work (some are also riders) and we all have the same engineering guess that stress is likely reduced.
I have access to SolidWorks and FEA, but am not an avid user. We also have the statics version, not the more advanced dynamics one, so I don’t know if I can add much via that tool, unfortunately.
I’ve considered trying to measure deflection of and between frame members in static and rocker versions, but I don’t know if that has enough fidelity to capture the small deflection differences that might exist.
Using strain gauges would be ideal, but I have limited experience with them other than pre-built load sensors.
Essentially, to do this with any level of accuracy that people would take seriously will take some time, money and skills I don’t have.
I wouldn’t take the lack of data from the makers as any kind of sign. Honestly, I am still shocked at what I see as a total failure of marketing by them. They can’t even seem to really identify and share the most common benefit to trainer motion, comfort. At least I have published something on that via my saddle pressure mapping video. Its far from perfect (one biased sample), but they should be doing snd showing that on a much larger basis. All that to say, their failure doesn’t mean there is no benefit to be had.
Just finished this. Used Lacrosse balls and tennis balls along with bungee cords to pull it when it moves forward and back. Bungees are noisy so I need to tape up the attachement points. I will also need to stretch out bungee cords shortly as they were brand new and will stretch. I will probably switch to the old rubber bungees as they wont stretch over time. I’m thinking it was around $130 Canadian.
Most of my rockers are made with reclaimed pallets.
Thanks! That’s good to hear.
I’m really hoping to get my plates rockin later today/tomorrow. Had to fix the paincave door first, couldn’t get in or out.
I whipped up another rocker plate for a co-worker. She’s ridden through a few trainers as a dedicated triathlete and is now on a spin bike as a result. She’s been having hip flexor issues which led me to offer a rocker to try and see if it helps at all. Covid friendly pickup too.
No reports yet on the feel but she’s pretty happy for fit to start with.
Looks great! Is there a pivot or support in the center, or just suspended by the 4 balls?
This is all rocker, I’ve found it to be a really simple method to achieve the movement without any extra hardware needs. The balls are just for the limits and cushion in the lean like you know already.
This is 18mm baltic birch plywood, with 6 rockers to help with the 90lbs spin bike.
Also goofing with a logo for our northern city for some fun.
That is great!, Thanks for the details and additional pics.
I love rib rockers for general simplicity. The feel is amazing for how little there is in them.
Your logo is quite cool too.
Just to try and increase your sales…if the CNC machine could add a name or initials without weakening…