This just popped up in my RSS feed. It's an inexpensive, lightweight rearview camera system designed for use on bicycles. I could see this system finding its way onto motorcycles or even ATVs. At just $180, that's pretty accessible for the Streetliner. I'd like to run at least a rearview camera, if not side view cameras as well to replace traditional rear-view mirrors. A system like this could remove all need for a rear window and help keep the outer aerodynamics nice and slippery.

One of the last things Chris Bangle designed at BMW before he retired was the car you see above. It was a concept for a modular vehicle with a flexible skin that would literally change shape based on what you were using the car for. It's trunk could change size and shape, and it could hunker down aerodynamically when it was time to go fast.

While obviously just a thought experiment, the flexible skin has me thinking about how to surface the Streetliner. Up to now, I've been planning to use foam and fiberglass to create the outer aerodynamic shell. However, looking at this concept and also remembering some fabric-shelled velomobiles I've seen online, the idea of using a more flexible material as an outer shell has a lot of appeal.

Firstly, it would greatly simplify construction. Since I'm not actually intending to mass-produce this vehicle, there'd be little point in investing the time or expense in creating a mold for a fiberglass body. Then there's the added complexity of creating all the mounting points that join that body to the underlying chassis. Then there's the added hassle of fabricating all the access panels and such needed to access key mechanicals under the body. I shouldn't have to take the whole nose apart just to top off the radiator, for example. Furthermore, creating a fiberglass shell of adequate thickness so as to be good and sturdy would mean adding a not insignificant amount of weight to the vehicle.

Instead, if I were to build a series of essentially ribs over top of the chassis and safety cage, I could wrap the body in some sort of flexible skin. There are a number of durable thermoplastics I could use that would be resistant to weather, stones, bugs an the like out on the road, yet also be heat shrinkable and easy to patch and paint. Hell, you could use model airplane covering. The cloth-style covering is durable, paintable and very lightweight. Access panels could actually be pre-fabricated in framing, rather than having to be cut out of a hard shell. If designed correctly, the whole look would have a great antique aircraft look to it — like dope shrunk canvas over wooden ribs, spars and bulkheads.

Fundamentally, air doesn't really care what a shape is made from. It just needs something to push against. Furthermore, an imperfect shape can still be very aerodynamic if it's smooth enough. Further still, every pound of weight shed from the Streetliner is a pound I don't have to push through the oncoming air. Additionally, I anticipate that building in this method would cost less, take less time, require fewer specialized tools and actually give me a much greater amount of flexibility to change the body shape as needed. Even the wheel pants could be made using this method — likely lessening unsprung weight and greatly simplifying installation. Anybody out there know of other examples of a flexible vehicle skin?

While none of this work has been directly related to Project Streetliner, it's all been tremendously helpful in laying a solid foundation of both component knowledge and general motorcycle understanding. As much as the Streetliner looks like a car in the latest renderings, it's still basically about 90% motorcycle. It's a three-wheeled cabin motorcycle where the frame is doing double duty as a safety cage. Having now pulled several bikes apart in pretty significant ways, I'm feeling so much more prepared to take this project on for real. I know I won't do this alone, but thinking back to a year ago, I'm now so much closer to being ready to kick this project off. Funding is still a huge question mark, but money aside, I'm feeling a lot closer to getting this project started from a place where success is that much more likely.

On the funding front, I'm thinking very seriously about putting this up as a Kickstarter project. I'm thinking I'd need to raise about $15,000, which is pretty small by their standards. What I'd love to get everybody's input on would be this: what incentives sound appealing to you guys? I was thinking perhaps of a range from high-quality prints of the renderings (like a poster series), all the way up to a complete set of kit plans. What do you guys think? What would you pitch in $50 for? How about $500?

This has me thinking. Why hasn't this happened with cars? I know there's a vibrant kit car community, but the majority of their time seems spent building Shelby Cobra replicas or other poor man's super cars. Why isn't there a kit car equivalent to the LongEZ? Where is that simple, economic, interesting vehicle that almost anybody could screw together and pilot? Maybe the Streetliner is that vehicle. Maybe this project, and others like it, can spur a small revolution in transportation where instead of big, heavy boxes of steel, some of us zip around in lightweight composite vehicles that get us back and forth to work. I like the sound of that. Who's with me?

Wheel Assembly Front (left and right)
-rim
-tire
-lugs
-hub/axle
-brake rotor
-brake caliper
-brake line
-brake pads
-steering arm (with hub/axle/bearing receiver)
-wheel bearings
-upper pivot assembly
-lower pivot assembly
-upper pivot bearings
-lower pivot bearings
-upper ball joint
-lower ball joint

Front suspension (left and right)
-upper swing arm
-lower swing arm
-upper swing arm pivot bearings
-lower swing arm pivot bearings
-center pivot shock mount arm assembly
-center pivot shock mount arm bearings (upper/lower)
-front suspension sub-frame assembly w/mounting hardware (including radiator mount points)
-shocks w/mounting hardware
-steering arms left/right
-steering column terminal assembly
-tilt lock rotor
-tilt lock caliper/pads
-tilt lock mounting assembly (on center pivot shock mount arm assembly)
-tilt lock hydraulic line

Safety cage / main chassis
-main hoop w/engine sub-frame mounting points and firewall
-secondary hoop
-tertiary hoop w/front suspension sub-frame mounting points
-roll bars
-door assembly
-door hinges w/hardware
-door latch/release assembly w/hardware
-seat mounting point assembly
-belt mounting point assembly

Body shell
-mounting point assemblies and hardware
-body shell panels
-radiator intake opening assembly
-latch assemblies for access panels and boot
-window assemblies (frames and canopy plastic)
-window latches and hardware
-windshield w/frame pieces and roof panel
-boot structure

Interior
-carpets or other lining material
-seat and mounting hardware
-safety harness and mounting hardware
-dashboard assembly
-steering column
-handlebar mounting assembly
-handlebar
-left controls (clutch, blinkers, hi/low beam, horn, grip)
-right controls (throttle, start, kill switch, hazard lights)
-foot pedal for rear brake
-rear brake master cylinder
-foot tilt lock pedal
-tilt lock master cylinder
-tilt lock locking mechanism and actuator
-parking brake actuator
-interior insulation panels (front bucket, sides, floor, door, ceiling)
-gages (speed, tach, temp, volts)
-12V accessory port(s)
-dome light and switch
-shifter pedal
-reverse selector

Electrical
-wiring harness
-front headlight(s)
-front blinkers
-rear blinkers
-tail light(s)
-battery
-rear camera
-rear camera display
-side mirror camera(s)
-side mirror display(s)
-iPad mount / charging dock
-interior environmental controls
-interior blower fans

Engine
-the engine itself
-engine mounting tabs and hardware
-front and rear sprocket
-drive chain
-ignition components
-radiator
-radiator hoses
-cooling fan
-fuel tank
-fuel pump?
-heat exchanger, air box, blower (for cabin heater)
-engine sub-frame
-exhaust pipe and silencer

Rear suspension
-rear swing arm
-rear shocks
-rear brake rotor
-rear brake caliper
-rear brake line
-rear inner fender
-rear rim
-rear tire

Just recently, I got another such message from a fellow called Russ. He's had similar ideas and appreciates where this design has come to, and inquired about the possibility of a future Streetliner kit. While a kit isn't a particular aspiration of mine for this project, the conversation we had via email inspired me to do a little update here.

While the lights have been dim here at Project Streetliner for a few months, I've been doing a lot of things that support this project. Specifically, I've been working on and off as a mechanic's apprentice down at Bluecat Motors. I write for their blog, and in return, they're helping me become more than just a recreational mechanic. I also spent a year working for an actual product development firm helping to bring actual products to market. I understand now — more than I could have ever known when I kicked this off — how unprepared I was to take this one when I started. That said though, I feel like with the knowledge I have now, I can actually really get started on this project. 

Direct work on Streetliner is still several months away, but I'm going to keep the concept finalization moving forward. I have no fewer than three motorcycle projects that need to be completed before any work on Streetliner starts. But the upside is that these motorcycle projects will help to prepare me for fabrication. I've also got a line on a building space. Details to come later. Stay tuned.

Thing the first
I have a lot of really cool stuff going on. I'm writing daily for Motoringfile.com, weekly for Bluecatmotors.com and both gigs afford me ancillary opportunities to do cool stuff with cool people. I was a guest host on two automotive podcasts this week (bimmercast and whiteroofradio). I'm becoming more and more regular on WRR and in fact one of my recent episodes was the most-downloaded automotive podcast episode ever on iTunes. Now that's not because I was on it, but still, it's pretty awesome. Working with Bluecat Motors is also giving me really awesome opportunities to expand my mechanical skills and have access to their expertise in customizing motorcycles. So there are a couple of motorcycle projects I'd like to see happen this season and that's going to take up both time and money that might have otherwise been used on the Streetliner.

Thing the second
I've really come a long way in this past year in understanding this project and what it's going to take to complete it. I'm actually very, very confident in my designs and in the feasibility of a vehicle of this type. Unfortunately that deeper understanding has some unpleasant realities. The design has evolved into something really, really strong, but unfortunately the improvements to the design mean that I'm not going to be able to meet my price criteria of $10,000 or less in materials. I'm looking at more like $15,000 before it's all said and done. Now that's not bad. That's the price of a really good motorcycle or a really cheap car. But it means that my original criteria are unrealistic. That has a domino effect on my timeline as well. The biggest thing that keeps me from starting construction isn't interest, it's money. I don't have the cash to buy parts. So my 2012 debut deadline is pretty much out the window.

So is it dead?
No. Not at all. I still want to do this. However, the scope of the project may change drastically. That, or it may simply be years before I get around to it. I'm thinking about doing a recumbent trike velomobile with a tilting front end and an electric assist. There are great bike paths here in the Twin Cities and I can get basically all the way to work on them. So that's an option. I'm also thinking about a Streetliner-style custom-built entry for the scooter Cannonball cross-country race event. We'll see.

Either way, thanks so much for everybody's support and everybody's interest. This project (and the site) aren't going anywhere, they're just not going to have my undivided attention for a while.

I'm in the middle of making a small-scale aesthetic prototype, which I'll post about later, but in the midst I made this little video showing how the double parallelogram tilting front suspension works. The prototype is made out of black foam core with hockey tape in the joints. Bone simple, very cheap and easy to modify. More on that later.

Nothing big here, just some new details. This rendering shows an adjusted cockpit position, door opening, and A-pillar spread. I'm considering flopping the door to the other side as left side impacts are more common on motorcycles. That would also mean a curb-side exit in the states.

It's a lot of spec to pour through for the casual reader, so here are the highlights as they pertain to this project.

• Must be of one of two designs: A high roll hoop (over the windshield), or low roll hoop (over the steering wheel).
• Must be protect from roll over, impact with an obstacle, and impact from another car.
• Must be able to support the weight of the vehicle if overturned
• Must be able to withstand the forces withstood should the vehicle go sliding on the cage
• Head restraint is mandatory and must prevent whiplash as well as prevent the driver's head from striking the main roll hoop. Depending on what seat you use, the head restraint may or may not be required to be physically tied into main hoop.
• Any forward bracing from the main hoop must be padded if the driver's head is able to contact it.
• Neither the cage nor the chassis can have an aerodynamic effect that creates lift.
• The cage must prevent engine intrusion into the driver compartment.
• Minimum tubing sizes for mild steel for vehicles under 1500 lbs: 1.375" x .095"
• The main hoop must be one continuous piece of steel, can have no more than four bends, those bends cannot total more than 180º, and the radius of those bends must be more than 3x the diameter of the tubing
• The front hoop must also have no more than four bends
• Rear hoop supports (cross bracing) must be straight
• The rear hoop, if possible, should go all the way to the floor and all joints should be reinforced by gussets or sheet metal webbing
• The main hoop must have at least two braces extending to the rear, and two to the front, attached no more than 6" from the top of the hoop, with an angle of at least 30º
• The front hoop requires two braces to protect the driver's legs
• Side protection should include at least two tubes connecting the front and rear hoops across all door openings
• The roll bar must be able to withstand stress loading of 1.5x laterally, 5.5x longitudinally, and 7.5x vertically where x is the minimum weight of the car.
• The race seat must be firmly mounted to the frame, and the back of the seat must be tied into the main hoop or its cross bracing unless the seat is specifically designed to be unbraced.
• The main hoop cannot be less that two inches above the driver's head
• A straight line drawn from the top of the main hoop to the top of the front must pass over the driver's head.
• The main hoop must be at least 15 inches wide where attached

There's a lot there, but there are a couple of things that had a really profound effect on my design. The first is the minimum tubing size of 1.375". I'd been doing all my weight calculations on 1.675" tubing and by scaling down to this standard, the estimated weight of my safety cage goes from about 130 lbs to about 80 lbs. That's a huge difference, especially for a vehicle this light and with the efficiency ambitions that I have. So that's a win.

The second significant standard wasn't so kind. It's this one:

A straight line drawn from the top of the main hoop to the top of the front must pass over the driver's head.

Here's what that looks like in my current design:

The problem here is obvious. I'm less concerned about the standard itself than what the standard is meant to prevent. Namely, the vehicle landing on my head. There are really only two solutions to this, at least that I can think of. Either both the front and rear hoops get taller (which kills my streamlining and visibility), or I'm going to have to brace across that gap in a way that clears my head. So I took a page out of the off road buggy book an designed a pair of curved A-pillars to connect the front and rear hoops.

What I've rendered here is incomplete, in the sense that there will be a lot more cross bracing than is currently showing. For simplicity's sake, I've kept this rendering to just the main hoops and cross members (plus the door). This change doesn't really have any impact on the body shape or my aerodynamics, thankfully.

What these new A-pillars do effect, however, is the canopy design and entry/exit. While the struts themselves may indeed bolt in and out in the end, they won't swing over with the canopy as it previously worked. In fact the whole removable canopy idea is kind of out the window at this point, I think. Instead, there will likely be more of a t-top arrangement where the side windows and perhaps part of the roof are removed and stowed. That, or perhaps just go Jeep-style and do zip-out covers that are heavy canvas or nylon with polycarbonate windows suspended in the fabric. This does afford an opportunity for an elegant permanent windshield, however. By curving the A-pillars in as well as up, that compound curve (which will be a bitch to fabricate, but worth it), should make getting in and out (via the door) easy as any normal car, if not easier. And at just over an inch in diameter, they shouldn't impede my visibility. While perhaps not as mean looking as the full canopy was, this new design is mean looking in a different way, and a whole lot safer. I'll take that.