The Ace Cycle-Car

Seattle-based Liberty Motors makes this Morgan-esque three wheel vehicle that I think is just fantastic. Scale it down a touch and put leaning suspension up front and it’s very, very close to what I want Project Streetliner to ultimately be, even in aesthetic sensibility.

The Ace Cycle-Car

But what I’m especially interested to see are the specifications on their website. Specifically, the 950 lb curb weight. Given that this vehicle appears to be made completely out of steel, including the body, and powered by a 103″ Harley motor, that’s pretty darn light. I really think that this makes my 500 lb goal for Project Streetlinervery realistic.

Suspension concerns

I have a couple of concerns about this suspension geometry.

I understand it, and see how everything connects and moves, but my concern is about the rebound and dampening. The wheels are obviously able to move up and down as well as tilt on the a-arms, but with the shocks hooked to each other it would seem like the suspension travel of one side is dependent on the other side being planted. This is disconcerting. The last thing you need on a leaning vehicle is wonky suspension. Sure this arrangement tilts just fine, but what happens when you’re deep in a lean and run over a pothole? Does the vehicle shoot one direction or another? It’s enough of an issue in traditional 2-wheel vehicles. So this is something I’ve got to get figured out during the prototyping process.

My prototype roadmap is as follows: Final concept » small-scale component prototyping » small-scale radio controlled, fully-functional prototype built mostly from R/C car components » large-scale prototype built from bicycle components and driven either by pedal power, electrics, or moped engine » full-scale chassis prototype with full drivetrain » polished full-scale vehicle made from chassis prototype and finalized.

Last night I swung by R/C Car Kings, a descriptively named shop in Burnsville, MN just up the road from my apartment. They’ve got every R/C car component known to man or beast in there. Fantastic stuff. I’m only just starting to understand the ins and outs of automotive suspension and as I’ve said before, I really want to engineer as few components for this vehicle as possible. Thankfully John, their resident suspension engineer, was on hand to walk me through my options. He expressed the same concerns I have about the pivoting, linked suspension on the design I’ve been referencing. He walked me through the different types of car suspensions and suggested either a king-pin set up (similar to what the Piaggio MP3 uses) or even a trailing springer suspension. Both are a tad tricky as they require me to essentially hang the entire front suspension (in terms of dampening and rebound travel) on the steering knuckles along with the brake calipers and wheels. It’s not impossible, it’s just complex. Anybody have any insights?

Thanks, YouTube

YouTube recommended this video for me this morning. A very interesting 48-volt electric trike commercially available in Germany and the Netherlands. There is something very sexy about the shape and upon further investigation of the websites associated with it, there is a very nifty roof option. Scaled up and with different (leaning) suspension geometry, this is close to what I am building. Although I really do like my Streetliner Concept #2, something more akin to this shape should be explored also.

http://www.sunrider-cycles.com/

http://aerorider.com/index.html

Suspension insights

Here we have a clear CAD rendering of the leaning front suspension in what appears to be an early version of the Aprilia Magnet concept. The one thing I couldn’t figure out 100% in looking at previous photos and video was just what exactly the struts attached to. It seemed clear that they attach to each other, but I knew there was a pivot in there somewhere. Looks pretty simple now that I can see all the components. Can’t wait to model this. I’m really curious how I’m going to source the upper and lower ball joints and spindle assembly. Might require some custom machining in the end. Hope not. The less of that I have to do the better.

Yet another tilting trike

@DuncanWilson sent me another great tilting trike video! This one has a close up of the lean locking mechanism, which is exactly along the lines of what I’d envisioned forProject Streetliner. I’m thinking a foot pedal that locks the lean on demand and a hand-lever (much like a parking brake) to keep it locked when desired. Looks like that’s a pretty universal approach.