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View Full Version : HowTo: Setting the front tire pressures equally each side.



mecsw500
11-05-2023, 10:09 PM
I use the following Amazon purchased product to set tire pressures:

AVID POWER Tire Inflator Portable Air Compressor, 12V DC / 120V AC Car Tire Pump, Air Mattress Pump with Inflation and Deflation Modes, Dual Powerful Motors, Digital Pressure Gauge

You dial in the tire pressure you want, press start and it inflates to the desired pressure and stops. Makes it easy to set both tires to the same pressure. I run 20 psi in the front Kendas.

I measured it against a calibrated gauge and it was less than 1/2 psi out. The connection hose has one of the better valve connections I've used and the whole unit seems pretty rugged, certainly for Spyder kind of pressures.

This one is 110 VAC powered as well which makes it easy to use in the garage, includes a battery backup for USB power storage in case the power goes out, you can't have too many of those battery backups.

So far so good, its lasted the season and seems to be still working fine. For the price it makes setting pressures on the Spyder really simple. A bit bulky to carry on the bike though.

It beats trying to get the fronts really balanced by hand with a pump and a gauge.

DGoebel
02-02-2024, 08:57 PM
Or make your own Dual Fill airhose system like JT's Spyderstore used to sell. Maso EMS2 did this years ago.
Here's his thread on spyder lovers https://www.spyderlovers.com/forums/showthread.php?79304-Made-my-own-quot-dual-fill-quot
We've made a few since JT quit selling them online.
Makes it really easy to balance the front tire pressure.

206744

mecsw500
02-02-2024, 09:43 PM
Now that's clever.

BTW, I used the air compressor I quoted in the original thread to pump up an SUV tire to 40 psi and it worked fine. Took a few minutes but it worked OK, no problems. It was less than 0.5 psi out at that pressure from my graduated gauge.

I like the T-piece dual air-hose system though. I never thought about that idea. That's clever that is.

BLUEKNIGHT911
02-02-2024, 09:47 PM
Or make your own Dual Fill airhose system like JT's Spyderstore used to sell. Maso EMS2 did this years ago.
Here's his thread on spyder lovers https://www.spyderlovers.com/forums/showthread.php?79304-Made-my-own-quot-dual-fill-quot
We've made a few since JT quit selling them online.
Makes it really easy to balance the front tire pressure.

206744

:agree: this is the only way the PSI in each tire will be EXACTLY the same ....Mike :thumbup:

EdMat
02-03-2024, 11:28 AM
One thing to remember when using a balancing rig like this is pressure equalization between tires is not instantaneous. It takes more than a few seconds due to the typical small pressure differences between the 2 or 3 or 4 tires and the small size of the tubing connecting them. Also, the longer the tubing, the longer it takes.

On the Spyder I use 3 leads at once and go for 18 PSI all around.

On my Mazda Miata I use 4 and go for 29 PSI all around. I typically go do something else for a couple minutes to allow plenty of time.

2dogs
02-03-2024, 09:13 PM
I’ve battled this tire pressure setting (TPS) thing for almost 10 years now and have finally come to one conclusion. You are never going to win. TP's are always changing and you can’t stop it, you can only control it to a small degree. If you are anal about your TP's like I am you’ll have to accept that. Whatever TP's you run at, and no one agrees on what that should be, outside ambient influences will always override your favorite settings. For example (only) I run 18 psi all the way around, and I used to use a three-way octopus to set them at 18 psi. Well, I found out that’s pretty much a waste of time. Now, I start with the rear tire because I only want to get up and down once. I will fill it to 20 psi and use a small digital air gauge to bleed it down to 18 psi. Then I do the same with the front tires to make them all match, and I am good to go. I’ll always keep monitoring my psi with my FOBOs which don’t always agree with my digital gauge. But I know just how much they differ. During a 100+ mile ride, my psi’s will change as much as 4 psi or more depending on which way I'm going, the time of day it is, and what elevation I'm riding at. But the thing is, as some will say, "Ride more worry less".

Woodenfish
02-03-2024, 09:58 PM
Tire pressure no matter how it’s measured by digital gauge or TPMS will seldom match. If you are within a couple of tenths of 1PSI you are good to go. Tire pressure equalization is stretching it. This is a motorcycle and not a Space Shuttle.

Peter Aawen
02-03-2024, 10:01 PM
I’ve battled this tire pressure setting (TPS) thing for almost 10 years now and have finally come to one conclusion. You are never going to win. TP's are always changing and you can’t stop it, you can only control it to a small degree. If you are anal about your TP's like I am you’ll have to accept that. Whatever TP's you run at, and no one agrees on what that should be, outside ambient influences will always override your favorite settings. For example (only) I run 18 psi all the way around, and I used to use a three-way octopus to set them at 18 psi. Well, I found out that’s pretty much a waste of time. Now, I start with the rear tire because I only want to get up and down once. I will fill it to 20 psi and use a small digital air gauge to bleed it down to 18 psi. Then I do the same with the front tires to make them all match, and I am good to go. I’ll always keep monitoring my psi with my FOBOs which don’t always agree with my digital gauge. But I know just how much they differ. During a 100+ mile ride, my psi’s will change as much as 4 psi or more depending on which way I'm going, the time of day it is, and what elevation I'm riding at. But the thing is, as some will say, "Ride more worry less".

THAT's ^ EXACTLY what you want to see after an hour's ride! :ohyea: An increase of 4psi means your tires have heated up enough to bring them to operating temperature, but not so much that they're over-heating and at an increased risk of failure; or so little that they are at an increased risk of failure!! nojoke

If they DON'T go up by (about, or close too... ;) ) 4psi, then your tires are OVER-inflated for your load/your current riding style &/or the conditions etc. and you have reduced traction, a harsher ride, less suspension compliance, a greater risk of punctures if you run over any road debris &/or potholes, excessive tread wear in the centre of the tread, yada, yada, yada! And if they go up by any more than (about, or close to... ;) ) 4psi, then your tires are UNDER-inflated for your load/your current riding speed/style &/or the conditions etc. and you are risking catastrophic tire failure due to over-heating, excessive tread wear on the sides of the tread, poor handling, breaking the bead during hard cornering, yada, yada, yada! And if you get NO pressure change after riding for about an hour or so (and this goes for your car &/or your trailer tires too!) your tires are GROSSLY Over-inflated and apart from the significant loss of traction and the very harsh ride you'll be subjecting yourself to, you are also likely to be pounding the crap out of your vehicle, excessively damaging the road surface itself, and I'm surprised you've got any fillings left! :shocked:

But riding for about an hour & finding your tire pressures are increasing their pressure by 4psi (+/- no more than about 1 psi on most reasonable quality but not necessarily perfectly exactly accurate tire gauges ;) ) from your cold start pressures is pretty much spot on for the vast majority of pneumatic radial tire users! :ohyea:


Sure, changing ambient temperatures, the load on your bike, the surface you're riding on, the speed you're riding at, how hard you're pushing it etc. etc. are all things likely to change the temperature increase of your tires and the air in them, so therefore the change of pressure, but if you're getting ABOUT a 4 psi increase (+/- as above) after an hour's ride (or however long your ride is over 30 or so minutes ;) ) then you are running tire pressures that are close enough to 'right' for some one riding a Spyder with all if it's inherent 'features' and capability - cos as someone mentioned (Thanks Woodenfish! :thumbup:) your Spyder is a motorcycle and not a Space Shuttle... And it's not a race bike or ultra high performance machine either! :2thumbs:

EdMat
02-04-2024, 12:46 AM
Tire pressure no matter how it’s measured by digital gauge or TPMS will seldom match. If you are within a couple of tenths of 1PSI you are good to go. Tire pressure equalization is stretching it. This is a motorcycle and not a Space Shuttle.

If you are within a couple of tenths of 1PSI you are pretty much golden.

Latrappe
02-04-2024, 07:00 AM
As Peter mentioned as you ride Tires heat up, so it is best to check them when they are cold.:chill:

pauly1
02-10-2024, 04:45 PM
That's well and good to try to be precise. However, if one tire is setting in the sun, guaranteed they will not be at the same pressure as soon as you turn it in the shady side. I'll wager that there isn't a rider on this forum that can tell the difference in 5% in differential pressure. Corollary: if you can, then riding East, switching direction to West, or vice versa, on a sunny day would drive you insane.

Ride more, worry less.