I also had the problem with the sun always being in the wrong place in winter. I found a pattern on an Aussie website while surfing a while back. I think it was an HPV site but don't recall for sure. Anyway, I made one out of posterboard, then used that one to make a modified version that is even larger and has a slot for the helmet mirror spar to pass through. Once I was satisfied with it I bought a black plastic presentation folder for less than a buck at the local office supply store and cut it out of the folder. The visor had to include the fold in the center of the folder so I put it right in the center of the visor and glued a left over piece underneath to stiffen the fold. It really does the job. I need to add a couple more slots at the base to let more air through at high speeds but it isn't enough of a problem that I've actually gotten around to it yet. Four small pieces of velcro hold it to the helmet and it stays put at all speeds I've been able to manage so far.
BTW, I saw in an earlier post that top downhill speed on a trike is limited to some low number (18mph?) due to stability problems. Let me assure you that I get above 40 mph on EVERY ride in my local area on my ICE Q NT and my top speed so far on one particular hill that I only visit occasionally has been 52.3 mph. Sit still, relax and let 'er run!
I think about the consequences of a catastrophic failure at those speeds but, hey, I'm addicted to speed. I just make sure I do a thorough inspection if the machine once a week. At least I'm doing something I love!
