I'm with toodeep on this one, keep your eyes on the trail instead of the dash, and if you find yourself bouncing off the rev limiter every gear then try shifting right before your teeth start to rattle. These things aren't racing machines, they are four stroke thumpers that don't have to be redlined every gear like the 2 stroke.
With that logic you don't need any gauges at all. LOL it's not like I want to mount it in the center of my windshield or that I spend 100% of my time tearing down a trail and staring at the tach. Trust me, this isn't going to be a safety issue. I found a tach, I just wanted to know if anyone had one with a light.
For many years all that was on them was a few lights for neutral, reverse and oil temp. On the BigRed if you wanted a meter unit you had to add it on. The meters on them are very nice for keeping track of oil changes. The tach shouldn't be a factor in any way and you'll probably find yourself never looking at it after a while. It is a fairly cheap little set up and won't hurt a thing.. BTW... Posts some pics when you do get one installed, everyone likes pics of mods that are done to the machines.
I'm definitely installing the tach. My wife confirmed it would make driving it a lot easier on her... she has a tendency to slow way down and leave it in fifth gear going 5 mph. Now I just have to decide if I get the Trail Tech or one of the cool old-timey dial tachs.
Pioneer riders do it side-by-side... it looks weird.