Meanwhile I took an impact at 23+ mph (23mph was the speed I last saw before the fall) two weeks ago due to a giant gap in the road that was across the entire surface. That was at 8am and I was back on my board at 4pm while carrying an extra 15 pounds to go get my elbow checked out. I did skip riding the next 2 days after the fall but that was because of being sore. Falling is a “free” workout every time it happens.
My knee and elbow are both still bruised and I can’t kneel on the knee or on the elbow but I can still do everything else just fine. Basically just can’t put weight on either in the same location they hit the road. It was definitely my worst fall I’ve had so far though and the only one I have had in over a year
Here is a look at the cad model. I’ve made some design changes, going to try new shock mounting points that should be better geometrically. The parts are ordered for the new upper arms and shock towers.
Bellow is a rough draft of what I was thinking for the next iteration. My biggest gripe with the board right now is the rear arm/shock tower gets in the way of my my stance and feels a little cramped. To combat this I was thinking of moving the pivot points away from perpendicular.
Wouldn’t it be better if the angle was shallower the more it compresses (asymmetrical 4 bar linkage with shorter bottom instead of a fixed angle parallel linkage)? That way when you hit something and it absorbs impact it is less likely to wobble
I would like to try that. My thinking in that scenario is when the truck angle decreases the leverage increases so it might feel more squirrely. Although that leverage gain might be offset by the leverage loss through the suspension travel as the deck height drops… On flexy decks the trucks actually increase in angle while flexing, since I never had issue with that, fixed angle just seems like a safe bet.
I would love to get these into peoples hands one day. You know that feeling when you find a smooth road, this board makes all roads feel like that haha. The carving is amazing, really impressive considering the weight. I’ll upload some videos soon.
Oh that looks great! Nice work, well done!
I‘m working on something in that direction as well right now, but just started to get into all the suspension stuff which is pretty new to me.
Could you help me out and tell me which spring damper you are using and which bushings you used in this places to enable everything to rotate?
I’m using this shock in 150mm. They sell different springs, I’m going from 250lbs to 350lbs. The one complaint so far is the bushings are really hard to remove which you need to do in order to replace the springs.
For the bushings on the arms I’m using this type.
I saw the build you got going on freesk8, very cool. I was going to suggest suspension for it. Another route that might interest you is cartridge style suspension. It is less tunable but very compact.
Thx man! I’m actually trying to integrate a suspension system in that board, but as i said, I’m pretty new to it and have some reading and researching to do.
I thought about ptfe lined bushings, but good to know yours work well.
I‘m geared 90-95kg, would you recommend the springs for 350lbs for that weight as well?
Were you thinking of doing a double arm suspension? With single arm the big drawback is the amount of angle change in the truck can be really high depending on the arm length and amount of travel wanted.
The spring rate really depends on many factors. The geometry, the amount of travel (for reference I have about 65mm of travel). Happy to give input if you have a suspension design.
Suspension is a real game changer. I don’t think we really need independent suspension since the trucks do a pretty good job of going side to side over impacts. Independent might do better but they seem so unstable. With the truck design I have now, it is more stable than rkps, yet more carvy.
I think ultimately I want to have a wooden deck. I do want to do bottom mount for that. There might not be enough ground clearance for the ride height I want to run which is 5 inches (axle height) and at least 2 inches of down travel and still be able to go over speed bumps without scraping… I also like the ability to switch to lipos and drop 10lbs.
You could pull this off without pivot angle changes if your suspension assembly movement is purely vertical. You’d probably need a slot of some sort.
Or super long arms such that your suspension travel creates a very small/acceptable angle change. Just brainstorming
Why though? If aesthetics, so be it. But for comfort and ride feel, shouldn’t most of that be taken care of and tuneable via the shocks, bushings, and angles?
If you’re willing to sacrifice some looks, i think you can really take advantage of the metal tube frame. You need places for your feet, at a certain height, of course. But in the center, you could drop your electronics box down into/onto the frame. You could utilize both if there’s not enough room under the deck
Scooters have forks, they are still pretty big tho… Single pivot, with 150mm arms was like 13 degrees of angle change for the amount of travel I have now which is bit much.
Part of the reason for the wooden deck is aesthetics definitely. There is still a little vibration that gets transferred to the deck that wood would do a good job of getting rid of. The tires due a great job at soaking up the road, the shocks seem to due best at bigger impacts… Idk if my knee will ever get back to 100% but seems to be heading in the right direction. For reference riding other peoples board over expansion gaps is jarring, I need all the help I can get… This might be the most comfortable board ever built already.