Funny I just went through this (btw, I have that Roadgear one and it can be frustrating getting a solid seal on the valve stem). I started researching tyre pressure gauges and got caught up in reading on it for longer than I care to admit. Worse thing is I didn't come away with a definitive answer on what is the best or most accurate. In the end $15 digital gauges can be just as accurate (or inaccurate) as spendy dial or digital gauges costing as much as $100.
A few conclusions I guess I did get out of it:
- Any gauge that can be calibrated should be calibrated at least every couple years (much sooner if treated roughly).
- Dial gauges are easily knocked out of wack by rough treatment.
- Dial gauges are generally no more accurate than less expensive digital ones.
- The +- accuracy rating can be misleading because a lot of companies are quoting the accuracy of what you can read in the display or on the dial, not the accuracy of measuring air pressure.
- Gauges are most accurate in the middle of their range. E.g. 30psi get a 0-60psi gauge
- In general gauges are off more at the lower end of their range than the upper.
- Apparently the larger the dial on a gauge the more accurate it can be tuned for and the longer it will last
It seems a decent digital would be the choice to go with. So I of course bought two of the more expensive probably no more accurate more maintenance intensive less sturdy dial type gauges. I went with them, Longacre brand (popular with car and motorcycle racers and enthusiasts alike), for these reasons:
- Longacre has a good rep in the racing world and they are probably as accurate as anything you can buy for under $100
- Price, $45 for the 0-60psi Deluxe and $25 for the 0-30psi Standard
- Brass internals and dampeners to increase accuracy and life span
- I could get the PSI ranges I wanted (0-30 for dirt bikes, 0-60 for street bikes and my truck)
- Can get a swivel chuck (easier to get under the rotors and don't require twisting the hose around).
- Has an air valve bleeder and holds reading when disconnected
- I read Longacre will calibrate them for free but have not confirmed this yet. (EDIT: nope, $19.95 + shipping)
These two will stay in my shop for the most part to set pressure after changing tyres, before rides, before races and track days. I'll get a digital (I like what Collyer put up) for under the seat and in the glove box of the truck.