Concept finalization


I’m gaining more and more momentum when it comes to finalizing the Streetliner concept. I’ll be putting together a more comprehensive full spec post later, but for now, here’s an update on the exterior design. I feel like I’ve finally found the art deco mojo I’ve been looking for all along. While the updates are subtle from concept Echo, a lot has gone on under the skin to help me arrive at this, the most finalized shape to date.

Most significantly, I realized that my seat and human analog were actually too large, as was my representation of the ATV drivetrain — each by about 20%. This meant that I could shrink the wheelbase as well as the cabin size by significant amounts. I had previously been concerned about the front to back balance of a rear-engine design, but these new proportions make it seem like it won’t really be an issue.

I accounted for a “jack shaft” that will inevitably be required to get proper rear wheel sprocket alignment. It also allows me to more easily monkey with the final gear ratio to the rear wheel. Additionally, it allows for easy fitment of a belt-drive, which will require much less maintenance than a conventional chain. I reworked the rear suspension in such a way that I can still get a lot of travel, but I don’t have to build a whole subframe back just to intersect the shocks. I’ve essentially just extended the rear swing arm. What may not be obvious from the side rendering is that there are arcs involved that would allow the shock(s) to be centerline instead of at either side of the swing arm. In the rendering there’s a ghosted wheel showing the full 6″ suspension travel. The jack shaft is inline with the pivot for the rear swing arm, which should keep things nice and smooth.

Front and rear, I’ve simplified a few things, and added others. Most noteworthy is the addition of a rear window, which is something I hadn’t had in the concept previously. The view won’t be great, but it’ll be much better than nothing. I’m thinking that rather than a rear view mirror, I’ll utilize a rear-facing camera built into the high brake light assembly. That will have a better view than any mirror system that would conceivably work (although I did have a hilarious rear-view periscope idea). I also abandoned previous modern-style brake lights and turn signals in favor of more conventional round lights. This is actually more in line with the classic design language from cars in the eras I’m trying to emulate. In the end, I’ll be somewhat limited in what I can find off the shelf, but standard round light will actually look better, in my opinion. I was designing those other signals and lights almost in a vacuum. I think they were cool looking, but in the end, such modern details would look out of place in this shape, I think.

Lastly, I finally paid some real attention to the front cross-section of the vehicle. I was able to resolve the shape such that I now have a completely flat front suspension parallelogram, but still enough body and wheel clearance to get about 40º of tilt out of the vehicle before the wheels bind or the body touches the pavement. I know for a fact that I’ve never put 40º of lean on any two wheeler I’ve ever owned, so this ought to be plenty. What’s more the cabin ought to be pretty comfortable, with little compromise toward comfort. It should just fit me, but with some reasonable room for comfort.

So let’s hear it. What does everybody think? If you’ve got other ideas, now is the time for them. As far as I’m concerned this is the design I’m moving forward with. I’ll hopefully be starting a small scale foam shape prototype today and I’ll share progress as soon as there is any. I’ll also be doing some small-scale safety cage models, likely in brass tubing, for structural testing and evaluation by people who know more about this crap than I do.

9 thoughts on “Concept finalization”

  1. I like where you are going on this..

    Can’t tell from the current drawings on how hard it is going to be getting in and out. I know earlier you were thinking one door. How does that work with the canopy in place (and the tube frame).

  2. The canopy is hinged along the right-hand edge, and the door opens on the left side of the cabin. So all in all, it’ll open up quite well for getting in/out. It’ll sort of clam-shell open on two axis revealing a rather large opening to the left side. I’d originally thought it’d open to the right side, but then I realized that going through parking garages and all manner of other things would get really tricky because the expectation is to be able to reach out of a vehicle on the left. Drive-through windows, parking garage ticket takers, toll booths, etc. So left side it is.

  3. Glad to see that you are making some progress. Thought you’d fallen off the project there. Would love to see progress pics of the foam and brass mockups as you go. Also, seems like we left off asking for some pics of how you construct the floral foam models. Did you happen to take any of those pics? And last, I forget, have you chosen your donor yet?

  4. Aaron, I’m going to share the modeling as I do it, I just haven’t done it yet. I’ll document both the foam and the structural modeling. There’s some full-size cardboard cockpit prototyping coming up too, which I’ll also share.

    As for the donor vehicle, I’ll be doing a full post about that soon. In short, it’s going to be a 2WD sport ATV with chain drive and reverse, per your excellent suggestions. I’ll elaborate soon.

  5. Suggestion – melding a rearview mirror into the trailing top surface of each front wheel fairing. Although as soon as you tilt you won’t be able to see jack out of them, I can’t see marring the shape with conventional mirrors. Perhaps one of those ridiculous tiny mirrors that tuners seem to like.

  6. I’d thought about that. My dad’s MG has a “wing” mirror out on the fender that he really likes. The pants do tilt with the body, so it might still work. What might be better and more likely is to take a page from the Aptera prototype’s book and do three cameras instead of three mirrors and have three small screens in the dash. Wouldn’t be inexpensive, but wouldn’t be hard either.

  7. I just thought that the relationship of the top of the pants to the driver’s head will change so much that you probably would not be able to see anything. Once you get the chassis mocked up you can test it.

  8. It’s true, I’m doubtful that it’d work, if for no other reason than the pants will float with the suspension, so they might be so shaky that I wouldn’t be able to see anything in them anyway. The camera idea really is my front runner right now.

  9. I really like the idea of a standard door,like streamlined electric on youtube or the C-1 by Lit Motor’.Yes,do use the wheel pants like the Aptera had,go with the camera’s after the vehicle is done to keep the cost down.Aircraft Spruce has some aero CM steel for the front links

Leave a Reply

Your email address will not be published. Required fields are marked *