Pressure Gauge

[pesto]

Ok possibly most pathetic thread, but I started looking into getting a tire pressure gauge for trackdays and am finding google results dizzying. What do you use and recommend?

[ellingly]

A relatively cheap one, and I aim for +3-4psi increase between cold and hot pressures. Gauges are often more precise than accurate.

My mechanic has a fluid filled uber expensive motion pro one, and it reads about a quarter of a psi higher than my cheap analogue Michelin branded one.

One thing - a gauge that holds the reading so you don't need to be reading it with it on the valve makes life easier.

[pesto]

Thanks. The precision vs. accuracy makes sense.

[Brian@speedymoto]

The longacre ones are really nice. The glow in the dark faces are pretty handy...

[oldndumb]

Can't remember specifically where, but I recall reading a test of air pressure gauge accuracy and the lowest priced AccuGage (sp?) was the winner.

ellingly has the right idea. Main thing is to use the same gauge and then monitor cold to hot deltas.

Myself, I use the $10.00 Slime electronic one from WallyWorld because it has several convenient features.

[BoDiddley]

A bit pricey but when I compared it to the three gauges that I had been using I found a # and - of 4lbs in all of them, none were spot on.  It will last a lifetime and worth it for the confidence.

http://www.motionpro.com/motorcycle/articles/view/261/motion_pro_professional_tire_gauge/

[Triple J]

The longacre ones are really nice. The glow in the dark faces are pretty handy...

+1 to Longacres. They aren't cheap, but they're accurate and they last, and they can be calibrated. That matters for the track. They have a blemished items section on their website where you can get better deals.

I have this one and it is awesome!

http://www.longacreracing.com/catalog/item.asp?id=982&catid=8

[Triple J]

ellingly has the right idea. Main thing is to use the same gauge and then monitor cold to hot deltas.

Not for the track (which is what the OP said). Tires have specific operating temperature ranges and 1 psi can make a big difference, depending on pace. You need to know that the tire pressure is...not +/- 3 psi or more.

[ellingly]

Not for the track (which is what the OP said). Tires have specific operating temperature ranges and 1 psi can make a big difference, depending on pace. You need to know that the tire pressure is...not +/- 3 psi or more.

I go off what the Pirelli and Michelin tyre techs (and at the track, not on the road) have told me and it works pretty good. Gets me happy looking tyres and good grip.

[oldndumb]

Not for the track (which is what the OP said). Tires have specific operating temperature ranges and 1 psi can make a big difference, depending on pace. You need to know that the tire pressure is...not +/- 3 psi or more.

You'll have to explain that for me as I always thought the amount of pressure increase (Delta P) from a warmed up tire was more significant than the actual gauge numbers. For example, a gauge that reads 1/2 pound less than a selected reference is still an effective instrument if you use it for measuring pressure increases at different lap starting and finishing pressures. In other words, determination of a percentage increase is not dependent on the gauge accuracy so long as the same gauge is used for both measurements.

[Triple J]

Both are important. The pressure increase is for sure a useful tool, but you also need to know that the pressure you're measuring is correct. It's no good if you think you're starting at 31 psi, but are actually starting at 34 psi. In short, get a good gauge. Any tire supplier worth anything is measuring pressures with a good gauge, and continuously checking to make sure it is accurate. As an example, our tire supplier has a tank where anyone can come check their gauge for free.

I used to be a bit skeptical on tire pressures, figuring +\- a couple psi wasn't all that important (I still don't think it is for the street) so long as the gain from cold to hot was OK (~10% is the general rule). At a race weekend this season I was struggling with my front end pushing through a relatively high speed corner. Dunlop recommended hot pressure was 33 psi (NTec DOT race tire), which my gauge pretty much confirmed. After the second time it happened I borrowed a buddy's Longacre gauge, and it showed my tire was actually a hair below 32 psi hot. I increased it to 33 psi and the push went away. I bought a Longacre gauge the next week.

You guys can do what you want...I think a good pressure gauge is worth it.

[ellingly]

Both are important. The pressure increase is for sure a useful tool, but you also need to know that the pressure you're measuring is correct. It's no good if you think you're starting at 31 psi, but are actually starting at 34 psi. In short, get a good gauge. Any tire supplier worth anything is measuring pressures with a good gauge, and continuously checking to make sure it is accurate. As an example, our tire supplier has a tank where anyone can come check their gauge for free.

I used to be a bit skeptical on tire pressures, figuring +\- a couple psi wasn't all that important (I still don't think it is for the street) so long as the gain from cold to hot was OK (~10% is the general rule). At a race weekend this season I was struggling with my front end pushing through a relatively high speed corner. Dunlop recommended hot pressure was 33 psi (NTec DOT race tire), which my gauge pretty much confirmed. After the second time it happened I borrowed a buddy's Longacre gauge, and it showed my tire was actually a hair below 32 psi hot. I increased it to 33 psi and the push went away. I bought a Longacre gauge the next week.

You guys can do what you want...I think a good pressure gauge is worth it.

For really accurate race stuff, knowing where it is at at hot also helps along with checking if it's losing or gaining pressure during the race.

For trackdays, which the question was about... Especially for someone starting out? Much more like a street scenario.

Knowing where your gauge is at is useful: if I hadn't done that, I wouldn't know where mine was at in relation to a good gauge .

Easy to read is good. Hadn't realised the Longacre ones have glow in the dark numbers. Might need to treat myself to that sometime.

[Skybarney]

I bought a simple Standard Tools gauge from Cycle Gear.  looks to be spot on for $24.00.  It has a large dial and saves the pressure reading.  It also has it's own bleeder so that you can air down while watching the gauge.  Handy and most importantly no batteries!

[BK_856er]

The Longacre gauges are great.  I use one and keep it safe like any precision calibrated tool.

Over the years I messed up several $20 Accugauges with the rubber bumpers.  Once like an idiot I checked the pressure of an air tank and exceeded the range.  Two other times a dropped them from 1-2 feet and they were subsequently off by ~5lbs.  The brass bourdon tube mechanisms are very fragile.  The factory will apparently repair/adjust for the cost of shipping, but I ended up tossing the whole collection because I lost trust in their reliability.

My kids and neighbors don't get to borrow my Longacre.  I keep a cheap pencil type to loan out.

BK