MYOG Tarp Help: Is this a bad idea?

[ArisaemaDracontium]

With the help of my experience seamstress wife, I am looking to put together a tarp for bike packing. My idea is to design a tarp that could use the bike as the structure for the shelter, or it could be guyed out. Basically, flip the bike over, stake the bars so it doesn't fall over, and then throw the tarp over that. The high points of the shelter will thus be the tops of the tires (keep the rubber side up), but this is also where we would put a couple guy-out points. The tarp would be asymmetrical so that the side of the bike away from me (probably the drive side) will slope fairly sharply to the ground, but the other side will be longer and depending on how I guy it out, could be an expansive shelter or a tight weatherproof nook.

Attached is a very crude diagram of what I want to do, not to scale, but the measurements are based on testing with a bike and tarp in my back yard.

Anyway, has anyone tried anything like this before? I could imagine a really dirty, muddy bike making this problematic... but other than that, it seems like a simply solution, much like hikers use their trekking poles.

Also, how do people make guy out points? I was thinking some narrow webbing and guyline tensioners would make for easy set-up, but is that a sturdy solution when using sil-nylon?

[Lentamentalisk]

If you google image search "bike tarp" you'll find a million different ways people try this. Definitely no need to stake the bike - it'll stay on its own. The only issue with  this is that the peak of the tarp is now taken up by your bike, so you can't really sit up. If you want to test your idea, clean off your bike and try this out with a blanket, just to get a sense for the space. You might find it cozy or you might find it claustrophobic.

[ArisaemaDracontium]

After I made a scale model out of paper and measuring out what we would need for fabric, my seamstress wife has concluded that the size of this tarp is impractical due to the size of fabric that is available. You can get some silicon coated nylon in 68" wide (the minimum we would need), but its tough to come by and the stuff we have on-hand is smaller. And, of course you can sew pieces together to make it larger, but extra seams are extra work, additional points for potential leaks and failures. I have also chosen to go with a fully waterproof bivy (OR Helium), rather than an ultra-light water-resistant bivy (was looking at Borah Gear), so I need less tarp.

I am going to keep the same concept and scale back a bit. Actually, this older thread is pretty close to what I think we will do. I won't need the tarp if I'm going purely minimalist, but it would be a nice addition for an emergency rain shelter and/or some extra living space. Should be really fast to put up and take up little space.