Tom wrote:

I think there could be a lucrative niche market in
affordable, functional cycle-commuter wear & accessories.

OK, I dropped by a fabric store. Picked up three remnants of polar
fleece (about $8 out the door). Experimented with the neon hunter
don't shoot me orange piece.
This morning I cut a rectangle about twice the size of the helmet
strap triangle. Cut along the diagonal to make two of them. Cut a
horizontal slit for the strap. Ta-dah!! (No s-w-ng at all)

ASCII art (NTS)

__________
|\ | cut along diagonal to make 2 triangles
| \ |
| \ |
| \ |
| \ |
| \ |
| \ |
|_______\|

____________
\ /
\ /
\ /
\----/ slit (about 1/2" in from edges)
\ /
\/

The remnant is large enough to make a set for everyone reading this
thread.

I'll post a photo or two once I get it refined, and sluggards can
send me $10 for a set.

--Karen M.