Tire pressure gauge for spoked wheels

Hi all,

Became frustrated recently trying to check tire pressure on my new 1200 8V SE. I used my trusty dial gauge that works well on my car but it was almost impossible to use on the bike because of the spokes. Ended up letting out a lot of air and not getting good measurements. Had to resort to a crappier stick gauge that I know is not very accurate.

Please advise as to accurate gauges that work with spoked wheels. I don’t have a compressor (yet) but am considering a small one. Thinking I would do well to get some kind of digital gauge and inflator combination...

Donzo

Donzo, I use a stick style that is available at auto parts stores and truck stops. It's about 12 inches long.
It's one of the long ones, and while it's not flexible, it has an angled tip that works well on both of my tires. My front wheel has a 90 degree valve stem and my rear stem is straight. It's about as accurate as they come. As far as small compressors, I recently bought a Dynaplug Ultra compact inflator that is extremely small but worked well in my test.

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This type works well on all of my toys.
If you buy wise, you only buy once.

I keep a digital gauge in each vehicle, plus one in the farm shop and one in the house garage. They're pretty cheap and very convenient. Most have lasted a long time, some over 10 years on the original battery. My tires range from 6 psi to 130 psi. It takes multiple gauges to cover those numbers.

I keep a digital gauge in each vehicle, plus one in the farm shop and one in the house garage.  They're pretty cheap and very convenient. Most have lasted a long time, some over 10 years on the original battery.  My tires range from 6 psi to 130 psi.  It takes multiple gauges to cover those numbers.

Hi Guys,

Many good nuggets found in your feedback:

tvboy: the Dynaplug compressor looks incredible. A must for my upcoming trips

Rick: digital seems ideal given the odd pressures indicated in the manual (33.4F / 36.3R)

eeyore: the Intercomp gauge seems to have the flexibility to reach the valve stems amidst the spokes and brake rotors

Many thanks all!

Donzo

Digitals typically read in .5# increments.  The odd values come from converting metric to US standards.  Keep in mind, the correct pressure for you, on your bike, and riding style, may differ from what the book says.  Gravity seems to have a firmer grip on me than on the 140# (63.636363.....kilo in metric speak) test rider, so I'm happy with about 39# front and rear.  Any less in front and it starts steering like a wagon.

Donzo, The Dynaplug inflator is small and really pumps the air but the selling point for me was the additional Shrader valve it provides to put your air gauge on. Meaning you can leave the compressor screwed to your tire's valve stem then attach your pressure gauge to the additional valve while filling the tire. If it had a built-in gauge then that would be cool but it had other features which sold me.
Peace of mind on the road. You should be able to use any gauge with it then. I understand you want a gauge to check the tires without having a pump attached.

Digital gauges may give more precise measurements, but they are not necessarily more accurate or reliable. Just because it displays a reading to one-half of a pound does not mean the reading is accurate to one-half pound. It also doesn't mean the gauge will give consistent readings.

Concerning analog gauges, I recently compared two Accu-gage dial-type gauges with two Milton stick gauges by measuring the same tire four times each with each of the four gauges. The Milton stick gauges were more reliable from test to test than the Accu-gages. All four gauges measured within about a pound of each other, with no way for me to judge which was closer to the true value.

I used a systematic approach, described here:

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with the results graphed here (click to enlarge):


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The graph shows a decrease in tire pressure over the course of the experiment, caused by loss of air during measurements. The Miltons are the blue and green dots.

In summary, the red and brown dots from the Accu-gage measurements are all over the place, while the blue and green Milton values are almost incredibly close to straight-line reflections of the slow loss in pressure. It's unfortunate that they read about one half pound different from each other, however.

I now think the 6-inch, brass tube, Milton model S-921 stick gauges are probably better than the Accu-gage dial-types that I had previously thought of as my standard. So I bought some more Milton gauges, and won't be worrying about this issue any more.

Don't waste money and storage space. Buy a reliable Milton S921 for about $6. It fits nicely with spoked wheels, of course, and works well with cast wheels too.

Moto

Hi Moto,

Thanks for the thorough and convincing evidence in favour of analog gauges. Even if I do eventually settle on something else, I clearly can’t go wrong with a Milton stick gauge given their low price and wide availability.

Donzo

Somebody has waaay to much spare time on their hands.

sideshowbob wrote:

Somebody has waaay to much spare time on their hands.

A long time ago, I was in an auto parts store where they had cheap dial gauges for sale for about $3-$4 each. I bought a half dozen and took them home and did a check similar to that outlined above, with good results. They were all very close, to each other and also to the expensive gauges I had. They're pretty easy to slip between spokes, but don't hold the reading after removing them from the stem.

Bottom line.... this isn't rocket science. The polar ice cap won't melt any faster if you're tires are off by 1 or 2 psi. See what pressures make your bike ride handle and ride best according to the gauge you have handy, and always use the same gauge on that machine.

Keep in mind that a fully loaded bike will require some extra pounds in both wheels (as well as luggage...) to cater for the extra weight - despite what the sticker under the seat (on mine anyway) that says they should be the same whether or not you have a pillion and/or luggage. I guess the original tyres on mine were Metzlers and a pressure change didn't alter the performance at all under any condition - always felt like I was riding with wooden tyres on cobble stones; wet was downright dangerous - unless you got them super hot, when they kinda worked better, but still felt awful.

I bought a Topeak D2 digital gauge after having similar issues. Has an angled head which also rotates through 90 degrees, so getting an accurate and quick seal onto the valve is very easy on both the front and rear tyres. Also, the way the unit "seals" as such onto the valve means that I almost get zero air loss when testing. Not cheap (about A$50), but after experimenting with various cheaper options that failed/broke/leaked air/chewed through batteries etc, I haven't looked back.

EDIT: Looks like these are available in Canada too (Canadian $43 or so).

You're welcome, Donzo!
This wasn't hard for me to do. Really I've just been too lazy to get it done, been thinking about it for years, and realized I had enough gauges to make an interesting experiment. The actual data collection took less than 5 minutes.
More than a question of accuracy, the reliability or consistency of the Milton gauges really recommends them for checking one's tires and experimenting with different pressures. If you don't have reliability from test to test you don't really have a way to determine how much you've changed the pressure. The Milton results were a real shocker for me.
Moto
EDIT: By the way, these things don't use batteries and they don't break. One of mine is 30 or more years old, the other probably 20.

Bought this from fortnine.com, works great :

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In my happy world I have 3 air compressors at my disposal. One for work, one in the garage and a baby one I can carry on the bike.

For air gauges I gotta admit I tend to hoard them. But my "main" gauge cost bout $100, used it at my last job. Big digital numbers, back lit and recently upgraded with a lock on chuck so I no longer have to hold it on the stems. Like Tanabuso I compared all of them against the main one. All within a pound of each other. The digital gauges were easier for my too lazy to get glasses ass to read.

And I fixed the straight valve stem on the back wheel by replacing it with a 90* stem. Problem solved.

Accu-Gauge
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Don't settle for an Accu-Gauge Chinese knockoff from Amazon

I use one of these. I’ve nothing to test it with but it’s well made and fits the GRiSO spiked wheels without a problem

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After many (many) hours reading reviews, I ended up on this one

Motion Pro Digital Gauge

Not the cheapest (probable the most expensive), but easily fits both front & back wheels

How about putting Fobo Bike sensors on your tires. App goes on your phone. Less checking needed manually. I’ve had them on my bike for about 5 years trouble free.

I have Fobo sensors on my work van and borrowed two of them to test on my GRiSO. The pressure showed up immediately on my phone and was similar to my gauge too. I'm leaning toward buying a Fobo set for the bike. Knowing if I have a slow leak while riding would be really nice.