Okay so after numerous search I just wasn't pleased with what I could find on bicycle rack. I was playing a lot trying to find an of-the-shelf rack I could modify to my needs to no avail.
So I've been playing with designing my own and after a few weeks of "ideation", various concept approaches, today I finally settled on a direction which I've spend most of the day working on. What do you think so far.

I still have a lot of work and details to include but so far it's not too bad.
I'm at 13 lbs. It will likely go up from there but I feel it's a respectable number for the base elements.

Key design point:
- Within car width (and why I specifically intended to go with fork mount approach)
- Not much higher than top surface of the boot, to maximize roadster top down experience.
- Access to boot when bike are mounted

 

That's a cool, clean design.

The tilt enables trunk access without removing the bikes.

I came across this design in my searches

It's definitely not as good looking as your designs, but the same concept. My front wheels are bolted to my bike, otherwise I might have given it a shot.

 

Yes, I came across that one once I think.
I was concerned it was quite flimsy and would shake like crazy.
But you are correct, I'm not re-inventing the principles. A lot of the rack out there have similar features. I just needed to come up with something I can fabricate

The main issue I came across with a lot of them is that aftermarket hitch brace more often than not reach under the bumper rather than go through. As a result they always have that perching connector piece which for the MINI makes the bike held really up high.

Also I'm trying to build this so it has more rigidity and limited shakes, but still stays light weight. That's why I'm using nice 2" tubing. The weak area in terms of vibration will remain the hitch hub itself for the time being.

So far it's going well. Last night I was able to identify source for the main materials. The tube were the hardest since 3/16" isn't as popular. 1/8" is too dainty, and 1/4 inch adds too much weight... but finally I did find a source

 

Very nice! Love the clean simple lines! If I had a bumper hitch, I'd want one.

Might be nice if it could flip straight up when temporarily not in use.

 

Definitely in the realm of possibilities

 

Your design does appear structurally stronger than the current crop of fork/hitch mounts.

I have one more week to go before I can clear bra my rear bumper and see how my MiniFini/Saris combo works out (see hitch installed Roadster thread). I too am concerned about height. With the MiniFini the hitch comes through the bumper at axle height.

I'm one of those weird single speed bikers, and for consistency I bolt on my front wheels in addition to the rear, but I may need to rethink things.

Are you considering mountain bikes? Road bikes with large 32mm wheels?

Is this simply a one-off for yourself or would you entertain others covering some of the build and material costs in exchange for a rack?

 

Quick answers:
- I understand your SS biker stand but really removing the front wheel has always been one of my favorite way to haul my bike around. A quick flip of the brake hub, a quick flip of the wheel release and popped the front wheel is
I don't think you can go wrong with a quick release even on a SS bicycle imho

- No I'm not considering mountain bike. I've never been very attracted and load limitation on the roadster are met rapidly. That said all the difference on this design would be a matter of length and spaces. There is a vertical brace I'm working on now to allow for vertical stability that is not shown on the images. Also the tubular pipe I'm using should have plenty of space for larger tires. I'll be getting a good 1.5" of width to nest tires cross section so I'm no worried about that. Again length of the tube and space between bikes is the most change that would have to occur.

- Right now it is simply a one off. I'm in depth with product development, And while I'm doing my share e of engineering I am not an engineer. So for simplicity and timing sake I'm working on this with my knowledge and gut feel. For this reason it would be difficult for me to manage product expectations in the product and learning curve this may require.
For similar reasons this is also not going to be designed for manufacturing so it is likely going to be expensive and not use the best cost consideration I would normally use on products I can rely more on manufacturing than my own skills. I don't know any one would go for it when all is set and done. But we'll see. This is somewhat experimental so as I'm going through the design it is not my intent to break the bank either
But long story short, for the time being it's designed as a one off until I know more about it and possibly have started a functional prototype.

But stay tuned, who knows

 

If the rack design ends up being Roadster-prohibitive, there's always this alternative:

 

Ha ha!

Yes, but where would the fun be

 

Looks good TG, nice streamlined design! Something that might help rigidity is using a brace that screws into the tow hook threads.
Keep up the good work!

Steve

 

Thanks Steve,

Hmmm, that is certainly an interesting thought.
I like it. I'll have to look closer into that.
I was thinking of two braces going under the bumper on both sides but after looking under the car it is a long way around making it difficult and not the best for rigidity. Using the toe hook would be a lot closer and direct minimizing flex.

 

Love the design. Very clean and looks super solid.