Spoke w/ a Unisport distributor

Well I just had the pleasure of talking to a Unisport distributor who was there at the end of the company. He said total production reached about 1500 kits before the 70's economy and a large stock of improperly stored firewalls took the last of the company's resources. Apparently the machine shop making the forward firewalls - the 1/4" steel plates that mounted the linear actuators & centered the tilting parallelogram & steering & lined up the frame, pretty much the linchpin of the design - at the end of production was storing them leaning at an angle instead of stacked flat. A slight bend started showing up and finished cars were wearing out tires quickly. The expense of dealing w/ this problem was the straw that broke the camel's back.

The linear actuators are military issue, from airplane landing gear (sorry not sure which plane), and even have a clutch that's plated off here:



I haven't had much time for the project this summer, but now I have a line to the original circuit diagrams and build manuals - once I've got them I'll get as much info online as I can, & I'll have an easier time replacing the broken old switches.

Where To

The goal of this restore is a drivable vehicle. Specifically, a fun ride for one or two that can handle freeways and rain, but that's longer term. This is a hobby, the project lives in the workshop I run my business from, so when I need a break from work, I'll try to make progress on the Unisport. Here's the plan:

-Step 1: Working tilt circuit-
I don't know how much of what's there is usable, several switches need to be replaced before I can turn anything on. My next post will map out the circuit, then I'll know where to jack in power to test. With the Unisport up on jack stands I won't be putting much load on the system, so I'll replace what's obviously broken, turn it on and see what happens.

-Step 2: Cleanup mechanicals-
Once I see the tilt system in action I can take everything apart and clean/replace. Some things will be updated instead of restored, like the brakes and possibly hubs and wheels, too.

-Step 3: Suzuki Burgman 400 donor
The big scooter donor is pretty capable, but I'll need the Unisport cabin & front clip to weigh no more than 400lbs to run the engine in it's normal range. I'm not too worried - there are a bunch of almost 700lb Messerschmidt & Isetta replicas running 2 people w/ Honda 250cc scooter donors - but I'd like to carry a passenger if I can so I'm curious about the actual weight of the Unisport parts. Rather than hook up the Burgman at the header tube like the original design, I'll slice up the scooter frame to save weight and length.

This biggest consideration is always moving forward, I want this project on the road.

Tilting Overview

Here's a first look at the Unisport's tilting system. Start w/ 2 of the buttons on the steering wheel (R1 & L1 are turn signals); L2 was once a toggle, connecting the ignition switch to the main relay controlling power to the linear actuators, so I'm assuming that's the switch that enables/disables tilting. R2 is a 3-position spring-centered switch (also needing replacement) that moves right & left to lean right or left...



And this is where the leaning happens, w/ the front wheels connected in a parallelogram hinged at the corners. The two linear actuators get power at the same time, so one's pulling and the other's pushing on the base of the parallelogram. Bottom and top horizontals are hinged in the center against the 1/4" steel firewall, so the push/pull creates lean for the body and for each wheel.




The circuit is pretty simple - 5 PRD relays & two "snap switches" w/ piles of dusty goo under them - routing power to two electric motors crosswired so when one is going up, the other is going down.

General Condition is Better Than Expected

Having had a little time to look over the Unisport I'm pretty happy about the overall condition of things. Lot's of surface rust & degraded rubber & brittle plastic, but much of what is there looks usable.


A big part of this project is appreciating the work of the designers - it's simple and sturdy design, no clutter. With the fenders and wheels off the hubs/brakes are on the heavy side but not as much as I'd originally thought.


The biggest unknowns are old switches (some brittle and broken) and old linear actuators w/o labels (dirty & a little beaten up, will they still work? force, speed, stroke? Who made them?). But overall the restore looks very possible, it's encouraging.

Unicar Corp Logo

This is the sun-beaten Unicar Corp sticker on the center of the nicely molded & simple dash. I haven't spoken to anyone who's driven a Unisport as an adult, but I know of at least 2 others sitting in garages, and it only took 15 minutes in Illustrator to restore the logo, so here's an oversize JPG:


EPS version in actual size 3/4"X2" is available if you need it. And I have to wonder about the Star Wars theme, very tie fighter, and George Lucas woulda been writing the first movie right about the time Unicar Corp existed... sorry to geek out, I worked for George at ILM for 10 years.

Walkaround Pics

Before getting into the systems in detail, here're a couple photobucket folders full of pics:

a full-frame walkaround -
http://tinyurl.com/y2dyqkx


& a closer view all around -
http://tinyurl.com/y25rr3u


The windshield is missing in these pics, but I do have it for install later. Otherwise you can see in the "clothed" pics that I'm missing the bottom side panels & belly pan (possibly all one piece?). Oh well.

Meet the Unisport

This is a new Unicar Corp Unisport circa 1973. I really don't know a lot about it. I know a small SoCal company called the Unicar Corp lasted 2-3 years in the early 70s making these vehicles. That alone is impressive, very few small car co's complete as much as a single vehicle. I've heard that the body was designed by Bruce Meyers, the creator of the classic Meyer's Manx dune buggy, and I heard they even sold a couple of these to NASA.

This vehicle is unique. The idea was in about 2 hours you could take your Honda CB450-750, remove the front forks, and attach the rest to the Unisport 2-person tandem tub with 2 wheels up front. Steering was by steering wheel, and buttons on the steering wheel controlled 2 electric motors up front, one pushing and one pulling on the tilting parallelogram front suspension - in other words, you could make the 3-wheeled vehicle lean into turns.

Why this blog? As a fan of small 3-wheel vehicles, especially tilters, I've seen the same small collection of old Unisport pictures here and there for years, including one very small and fuzzy pic of a Unisport mid-lean, but very little info. Then out of the blue, someone posted a Unisport for sale on craigslist.org. It's been sitting under a tarp in Texas for the last couple decades, it's rusty (but not pitted), the tech is 37 years old. The state-of-the-art-1970s disc brakes are 1/2" solid steel. I bought it.



This blog is to document the restoration. This is a partial restore - the goal is to get the vehicle back on the road with minimal work (ha ha), just adequately powered by a 04' Suzuki Burgman 400 donor that I have stripped for another project. Identify, test, remove, clean/replace/rebuild, put back together, drive. And I'm hoping if you're reading this blog you'll come back & help w/ triage in future posts, reverse engineering the tilting system should be fun.

What happens when you push the tilt buttons? Can I restore the old tech as-is? Can I resist updating everything before I even drive it (1/2" X 9" solid steel discs as part of the unsprung mass on a light weight vehicle? Practically 4-decade old microcontrollers w/ dusty piles of goo under them? C'mon!)? I don't know what'll happen, I just know the dormant headlights of my Unisport are crusted with old dead bugs. Somebody was tearing down the road in this thing, probably a big smile on their face, teeth bug-free behind a glass windshield, looking for more curves ahead.