2_i 

This is to solicit recommendations for a digital pressure gauge that works well with Presta valves.

In the past I used a Meiser mechanical gauge, but over time it started giving erratic or no readings. Having success with conversion to digital in other instruments, I've got a Topeak D2 gauge, based on positive Amazon reviews.

Using the high resolution of D2 has been a pleasant experience. Unfortunately that gauge turned out to be, otherwise, a poor compromise in the area of utility for both Schrader and Presta valves. In the Presta setting, the central post sticks out and depresses the valve well before you manage to secure the gauge over the valve. In effect, you lose a good deal of air before you manage to take any measurement. To compensate, you try to place the gauge quickly over the valve. However, misalignment is likely in effect of the bulky stem of the gauge. If the gauge and valve are not properly aligned and you apply a large force to get it done quickly, you can damage the valve. In fact, today I managed to rip the pedestal of the valve in a pumped tube and decided to move on from D2.

Have you had any good experiences at the interface of digital pressure gauges and Presta valves? Thanks.

Jed19

Why digital? I have owned a Zefal Twin Bicycle Tire Gauge for a long time. It works well and has been very durable. Like you, I remember buying the Meiser/Presta and returning it b/cos of the unreliability.

Another thing about the Zefal is that the same gauge can be used on Presta and Schrader valves, while the Meiser are valve-specific.

Of course, I see that it is now super expensive. I bought mine about twelve years ago for about $7 or so. I won't hesitate to buy another one were it to pack up.

Hendricks97

I bought a SLime brand digital for under $10.00 at Performance. It does only work for Presta (they have a Schrader version also) but all of my bikes are Presta anyway. Its worked fine so far

2_i 

Thanks for the info. With this and upon reading additional critical and conflicting opinions on the web it became apparent that different possible solutions at present might each have drawbacks.

Frustrated, I started looking at my Topeak SmartGauge D2 to see whether maybe I could take it apart and remove the central pin. In experimenting, I actually found a simple solution to the Presta valves. The solution is to use the Schrader setting, but with a twist. Namely, all that the Schrader setting does is to lock the central pin. However, that pin can both locked sticking out of the gauge as well as locked in. If you push the pin into the gauge in the Presta setting and move the valve choice lever to Schrader, the pin stays locked inside and you can safely measure the pressure for a Presta valve without letting much air in.

MudPie

I have one of these Topeak (I know I didn't pay this much for it 8 years ago): https://www.amazon.com/Topeak-Smart-D.../dp/B000FIE4Q8

However, I always felt the mere act of measuring pressure decreases the pressure in the tire, especially a road tire.

I do have a pressure gauge on my floor pump, which is an accurate measurement of the tire pressure right before you disengage the chuck.

My Topeak pressure gauge is stashed in my car's glove box and used for checking its tires.

durrrell

Here's the one I bought for $12-13. 3 different types of measuring, i.e. bars/PSI and it can be used on both Schrader or Presta valves without changing anything. It seems accurate, is easy to use, but there's just a couple slightly annoying features on it. After measuring the air, you have to turn it off and then back on to measure again. Oh, it has a light too.

https://www.pricepoint.com/detail/160...p=245%20SETBT7

2_i 

durrell, do the opposite sides of the gauge mount on the Presta and Schrader valves or is one side of the gauge used only, for both types of valves? From what you are saying, is the pressure readout staying constant during bleeding? The Pricepoint site says that it has a bleeding valve. Thanks.

Bianchigirll 

Get yourself a Silca floor pump, then learn how it feels against your thumb when the tire is at your desired pressure for when you flat on the road.

2_i 

I learned not to argue with religious convictions.

reddog3

Good for the poster who has a Slime guage that works, but the one I bought doesn't work with all Presta tubes- just some.

Looigi

Yes. With a pump gauge, you read the pressure as the pump piston is moving down and air is going into the tube. Do the last few strokes slowly to get an accurate reading. Once the piston of the pump stops moving and air stops flowing into the tube, the presta valve can close and you're left reading the pressure in the pump hose, not the tire.

bored117 

Topeak D2 one works fine for me. I also have analog gauge mentioned above and they mostly agree but digital is definitely easier to read.

durrrell

It has separate mounts for each type value. There is a button you can push to bleed off pressure. The more I use it, the better I like it. I was mistaken in that there is a button to clear the reading to retest. It is also lighted which is a GREAT feature as my garage light is very weak at night.

While it is taking a reading, it takes 3 readings before issuing a final reading. It also loses very little air when you place/remove the gauge from the valve, less than .3 lbs, which on a 110+ psi tire is nothing. It is actually a pretty remarkable gauge for the money.

2_i 

OK, I've got a Beto gauge of my own and it is a significant improvement over Topeak D2. Hardly any air is lost during a measurement and the gauge goes on securely over a valve, without a danger of breaking that valve such as for D2. The illuminations of the readout and of the valve area are both very handy.

There is still indeed some quirkiness to the gauge. The first reading the gauge take is practically always off, typically by half, but then correct readings follow, somehow automatically. Also the gauge defaults to a setting where the reading is forgotten when the gauge is taken off the valve. Because of the separate mounts for Schrader and Presta, the range of angles for the mounts, to facilitate mounting and reading, is limited. In spite of those issues, the gauge is a keeper. Thanks durrell!

ultraman6970

100% on this one, it is nice to know how much air are u pumping into the tires but with time by only touching them u know if the pressure is right or not. It you tap them the tire changes the tone depending on how much u have in there.

mechBgon

I have the SKS and it's pretty good too. Swivel head, separate valve chucks, bleed button, backlight, auto-off and a reading-aqcuired beep. Repeated uses don't draw the pressure down much... if anyone has a burning curiosity to know how much, I can report on that on Monday when I'm back down at work.

2_i 

Some market update to this thread: In Japan the Beto gauge is sold under the Panasonic brand, at 3x the typical US price.

ultraman6970

I'm w/u on this one, some guys are just to anal for air pressure and has to be right all the time, like 2 to 3 pounds more would make a difference in a regular rider.

Camilo

Have you found you can accurately tell the difference, say, between 90 and 100psi... or 100 and 110? Are you able to just do away with routine topping off of the tire based on feeling it? I just cant' distinguish between "hard" (which could be 80 psi) and "hard enough" (which would be 90 - 100 for me).

But I just go with the gauge on my floor pumps. I have four different pumps and they are all accurate enough so I haven't had a pinch flat in 5 years, and then only because I didn't top them off for 4 days. I try to go low-ish on my pressure (90-95 front, 100-105 rear, 23mm tires), so accuracy is pretty important, and the pump gauges do just fine.

When it comes down to it, the "feel" test really is irrelevant for me. I just top off the tire routinely - easy, quick, fool-proof. For me, there's no point in guessing when it takes 30 seconds to top off a tire.

I tried a pressure gauge, and it always seemed the air would leak out significantly before the reading would occur, so I just quit using it. I don't know what they're good for if a pump has a gauge.

On the road, I just pump with my mini pump as hard as I can possibly get it and (from later testing), I know it's around 90, if I really grunt.

vredstein

I've had a Schwalbe presta-only digital gauge for a couple years and had no problems. Since it's presta only, there's no central post, just a rubber gasket that surrounds the knurled presta piston. It shuts off after about 10 seconds of non-use so it saves batteries. I've had the same batteries in it since I first bought it.
With all heads, whether they're analog, digital, stand alone, or on a pump, you have to insert it onto the valve as quickly as possible to minimize air loss. When checking pressure, I'll only unscrew the presta valve 1/2 or 3/4 of the way, minimizing the amount of shaft that exposed and unsupported.

ultraman6970

Camilo... yes you can notice, as bianchigirl says, you tap them and you know. The issue I see is that you are like .. ok tell me this is 120 and that one is 110.. tell me which is which... doesnt work like that, im good at it but that good, doubt anybody can tell anyways Just doesnt work like that but look...

One detail... with tubulars i easier than with clinchers because clinchers vary in the surface, some are extremely hard, other clinchers no matter how much air you put to them they remain soft in the surface but just do an experiment... always put 90 pounds in the front and 120 in the back (same clincher brand and model) and tap them, they will sound different, or just touch them to feel them. Do that everyday and you will start hearing or feeling the difference.

I mean probably you wont be able to notice between 105 and 110 but if one day you get a flat and you just have a CO2 bottle you might be able to tell if the air you put is around what you want or not... oh i put too much air... oh, still needs tiny more... but to know exactly what you have in there, pinpointed accuracy no way to know

No flat in 4 years here using tubulars but with the time you get used to touch and feel, and lets face it.. 5 pounds more or less in the tires for a weekend warrior wont make any difference Even 10 pounds wont make a single difference Obviously is not the same 90 to 100 in the front that 60 to 70 in the front, we have to put everything in the respective range too. But pretty much in the ranges you are managing 5 pounds less wont affect your riding at all. I use tubulars and i use the same ranges you do, my only difference is that I take 50% of the air off the tubulars when i'm done with the bike. SO if i have to ride again I'm forced to get the pressure back to what I like, thats why I get used to the tapping in case the gauge is not reading well.

The other reason of the tapping is because back in the day we did not have pumps with gauges as today, so you had to kind'a guess touching and tapping the tubulars, at the end you get used to it. Too much work and not accuracy for the guys that are anal with this but it worked for me back in the day