First, I considered the 5" tach, but I think it's a little too big for my liking. Then I was considering a 3 3/8" or 3 3/4" tach. I'd have to do the same thing you're thinking about, with a clamp on each side of the handle bar clamp, and then a strap between the two. I'd have to put another kind of gauge on the left side, to replace the small tach, to balance the clock on the right side. Maybe a transmission temp gauge.
For now, I've decided that until either Mountain, or Marv, or someone else comes up with a Tach mount for the pullback risers I have, I'm gonna let it slide. I only look at the tach when I'm checking idle speed or occasionally when cruising. If I'm really on the Throttle, I rely on my ears and the shift light. So maybe I'll give that new Carb a little more thought instead. :wink:
Let me know what you decide on. If you mount a tach, maybe post a picture?.............Don