A couple of months back, when I'd got the hang of riding the SMGT and was just venturing out on it in traffic, I thought I needed a mirror. I'd randomly lost about 30dB of hearing in both ears after a nasty asthma attack, and felt very vulnerable not having any idea what was going on behind me without looking. My hearing returned to normal a couple of weeks later, by which time I'd become proficient at looking over my shoulder, so it bothered me less.
Until the July WARTY, when I heard the third of a group of cars coming up to overtake, ran out of room to crawl forwards in the passing place I was in, so hit the brakes and put a foot down. Except the car turned out to be boab's tandem right in my blind spot, and we proceeded to get nicely tangled.
After a couple of other incidents, I've decided that crashing into tandems at low speed is the SMGT's major hazard (this is less silly than it sounds - a loaded SMGT has very similar speed characteristics to a tandem where hills are involved, so you tend to end up riding with them), and that a mirror would be genuinely useful for situations where I'm likely to have other cyclists (which you can't reliably detect by hearing alone) around me.
My Eustachian tubes are crap, and mild but disorientingly intermittent hearing loss is an occupational hazard, so it'll be useful next time that happens, too.
I have a B&M Cycle Star on order. It seems decently made, and doesn't require a bar-end to mount to.
