site  contact  subhomenews

Recumbent trike front suspension Mark-2 assembled

May 17, 2024 — BarryK

Continuation of the recumbent trike front suspension conversion project, this is the previous blog post:

I am referring to this as "Mark-2", as there was an earlier design that I partially built then abandoned.

There is going to be a "Mark-3", as I already have in mind many improvements; however, I intend to progress the Mark-2 right through to a rideable trike. The reason for doing this, is there are so many more parts of the trike that have to be built and tested.

The steering for example. There are a lot of questions about that, so have to experiment. Mark-3 is intended to be based on the same dimensions, and whatever is worked out for the steering in Mark-2 should be directly applicable.

Anyway, here is Mark-2 front suspension assembled on the trike:


As you can see, I decided to go with the Heim joints; however, not for Mark-3 as I have conceived of a simpler and likely lighter design for the swing-arms.

The shock absorbers are quite soft, rated at 200 pounds per inch. That was the softest available for that model of shock absorber. Sitting on the trike, suspension seems OK, but won't really know until it is loaded and out on the road. There will be a lot more weight up front due to the electric motor, and I will probably mount the battery at the front. The next rating-up is 350 pounds per inch; anyway, we shall see how it goes.

The suspension retains the ability to be a tilting trike, as where the two shock absorbers meet is a pivot. It is currently locked in place, but by simply removing a bolt it will swing freely. The intention would be that the central pivot will be linked to the steering mechanism, so that the trike will tilt when cornering.

At this stage, don't know if will ever get to implementing the tilting. It depends on cornering stability. My trike is only 750mm wide, measured from the extreme ends of the wheel spindles. The main reason for that is I want it to fit through my front door, so can keep it inside. Also, if I go touring and stay overnight in a motel, want to be able to bring it into the room.

All recumbent trikes (that I know of) are over 800mm wide. My "320" trike is, or rather was, I think, 870mm. Making it narrower will decrease cornering stability. But this is where I need to get out on the road and find out whether 750mm width is OK, or whether have to go for tilting. I'm not going to be racing around corners, so likely it will be OK.

I should also mention that here in Western Australia, the legal maximum width is 800mm. Which means that, technically, all recumbent trikes in WA, apart from mine, are illegal. Not that anyone is bothered by that. Prior to June 2022 here in WA the legal maximum width was only 660mm, but the police turned a blind eye to trikes and mobility vehicles that were wider.

Anyway, it is continuing to be a fun project, as is going to the workshop.   

Tags: light