Topeak SmartGauge D2 Digital Tire Pressure Gauge – Presta/Schrader Compatible, 250 Psi/17 Bar, Precision Air Pressure Reader with LCD Display for Bikes, Motorcycles & Sports Equipment

When my Toppeak analog gauge finally fell apart after over ten years of heavy use my first thought was to get one exactly like it, but I was attracted to the feature on this gauge which allows you to release tire pressure while reading it as it drops and the fact that it has a single hole head which is compatible with both Presta and Schraeder. Months later, I couldn't be more pleased with this gauge.When I look at the gauge on my Lezyne Alloy Floor Drive Pump as I'm pumping up the tires the gauge on the pump is fairly accurate, but you can't increase pressure by only a pound or three, and you can't decrease pressure with it at all. So when I overpumped the tire--as on most any floor pump--I would have to remove the pump from the valve, take a wild guess about how much air I should let out, and repeatedly use my old analog gauge to check it until it was roughly the pressure I wanted.With this gauge I always put more pressure than I need in the tire, then remove the pump, measure the pressure--which is too high at that point--then press the button to measure the pressure as I use the release button to get it where I want it.This would be a pain in the butt if it weren't for the swivel head on the gauge which allows me to point the display where I can easily see it rather than change the position of the tire or tilt my head to view it.Overall this process has become quicker, easier, and more accurate due to this gauge. And it's a great benefit to other riders when I'm on a club ride or volunteering as a ride marshal in a community bicycle tour that with the flip of a switch I can change between Presta and Schraeder valves without having to take it apart or switch around any gaskets.A lot of people will tell you that you don't need a gauge, that they can tell just by squeezing the tire. That's nonsense. I used to think that until I finally bought a gauge and found out that when my mountain bike tires feel rock hard by the squeeze test they actually have only about 25 psi in them when they should be at least 50 psi, and my road bike tires might feel rock hard at 60 psi when they should be 120 psi. For reference, your car tires only take about 35 psi.And by the way, this is a great gauge to use on your car too. I check the tire pressure on my car at least every month, and more often when the seasons are changing. Sometimes I need to put more air in using the electric pump on my Slime 50051 Safety Spair All-In-One 36 Piece Roadside Emergency Essential Kit and sometimes I need to let out a pound or two of pressure. With this gauge, I don't have to guess how much air to let out when the pressure is too high, checking each tire multiple times until I have it right, or use the needle on the analog gauge to get an approximate pressure reading.Whether on my bikes or in my car, inaccurate tire pressure can mean compromising fuel/power efficiency or traction, and with gas prices what they are these days even another three miles per gallon matters in my car, and incorrect pressure in bicycle tires make for a harder ride and lower endurance.So instead of thinking that maybe this is a little over the top, I recommend you buy it. The price is certainly reasonable and I doubt you will regret it.

Funny thing is, I was ready to return this thing in a fit of anger being sick of things not working when I buy them. But after a few minutes of forcing myself to make it work, I find that it works just fine. It's user error.Honestly, I would give this 4 stars due to the packaging. Oddly, it's a small box on a card, however, the unit is exposed which means anything that can scratch it if you ship with other items. There are some cosmetic marks on it, but, as time goes on, I will use it, drop it, scuff it, etc. So, it's fine. I just wish the item was IN the box. The only thing in the box was the battery and limited direction sheet.I first had no belief that thing was working at all. There are two settings. You will notice the yellow switch at the top, and you slide it to the tire valve type, Presta or Schrader. In my case, and on most bicycles, the valve is a Schrader. On the unit there is a small image of the valves, the Presta looking pointed, and the Schrader more of a stump. So, that simple selection will get you on your way to the next part.The power button is also a reset button. One click to turn it on... and it will automatically turn off after 30 seconds of non-use. Hold it 3 seconds to shut it off. When taking a reading, and want to reset to 0, hold the power button for 1 second. There is a beep acknowledgment for every action.Then there is the Unit button where you click once to rotate through 3 choices of PSI, Bar or kg/cm2. For the most part, just getting the correct PSI is all you need. You know the correct PSI and Bar range by looking at the side tread of the tire. Very hard to see, but it's there. In my case, the PSI range is 40-65, so obviously, you pump until you get into that range and where you are comfortable. Use the SmartGauge to check in intervals, and if it's higher that you would like, use the yellow button on the side to release air.Now, the frustrating part is taking the reading, but only at first. Then you realize how great and simple this is once it clicks in your head. There is an unexplainable "aha" moment after using it a few times. After you curse and scream "5 PSI, this is BS!" and then "12 PSI, WT..", you then get the position that is comfortable for you, and you get a perfect reading, with no air loss. For me, I found putting my thumb on the top grey part and put directly on the valve, it beeps in one second, and I get the perfect reading. You of course doubt the reading, do it 5 more times after resetting it, and realize it is the same number each time. You then think it's broken, go to the next tire, and see that it's a different number. And then return to the other tire, to see that the number is back to what it said before. In other words, that's exactly what I did, not trusting this thing was working at all, and about to send it back.The short story is that you need patience, and after a few readings, you will feel confident it's telling the truth. It's well made, sturdy, and the head of the unit rotates to get a comfortable angle in any position and visibly see the screen. But you don't really need to watch the screen. Just put the thing on the valve for one second, beep, take it off and read the number. Simple.I have found myself buying a heck of a lot of Topeak products, and happy with all. The Topeak Explorer Bike Rack is what started it with me. The easy ingenious click on bags, baskets and accessories are top notch. I have no idea why I doubted this SmartGauge.

I have been looking a long time for an accurate prseeure gauge for Presta that does not lose air while checking. This is the best I have found so far. It does take a little practice. Once you figure out how to place it and push it on, it works well. I lose exactly one lb of pressure with each check. I don't think you can find a gauge that does better than that. Line it up and push it straight on quickly (but not too much force...just enough).Now for the problem... I was prepared for a problem with the battery after reading other reviews before I bought this. When I opened the package and installed the battery, nothing worked (blank screen). I tried a brand new battery. Still nothing. I was ready to send the unit back! The original battery was fine. I had read a review that had said to remove the inspection sticker that is inside the battery compartment. So, I did and while I was experimenting with the battery again I heard a beep. I noticed that I could move the battery around and hold it in place (without the cover) to get a readout on the screen. So, I cut a small piece of rubber from an old bike tire inner tube and placed it directly on top of the battery (between the battery and the battery cover). I then screwed the battery cover on and everything worked fine. I have not had a quality control issue with Topeak before. Other than this, the unit seems well built and accurate. If it were not for the battery problem, I would have given it five stars.I have a Lezyne alloy drive floor pump with built-in gauge (another excellent product I got through Amazon). The pressure readout is exactly the same on the floor pump and on the Topeak. Since I am pretty sure the pump is excellent quality, this leads me to believe that the Topeak gauge is accurate.