Max pressure ratings and real life application

[Guest]

My natty new hoop ( us cool types call tires hoops ) has a max psi at 42
that is with a max load of 6 hundred and some pounds

Do that mean with my 420 dry bike plus fuel and fat bastard driver should get a very high PSI?

My chassis sticker says 32 IIRC.

[koolaid_kid]

You should use the 10% rule. Start with cold tires, inflate to xx psi, ride until tire is hot, check pressure again. It should increase 10%.
For example, I run 32 psi front, 36 psi rear. It increases around 10% after they get hot.

[gsgeezer]

I run 32 psi front, 36 psi rear. It increases around 10% after they get hot.

Those are the same psi I use, and it seems to do great.

[JEEPRUSTY]

Im going to do that 10 per cent rule if it ever stops raining.

This was the easiest tire mounting I have ever done. Put the dot beside the heaviest spot which was just a few degrees away from the stem.

And no more that 35 PSI and POP POP and away we go.

I really need to make a balancing stand as its seems my heavy spot has moved a fifth of a turn or so.

[sedelen]

I run my GS1000E at about 26 front, 31 rear,
I run my GS1100E at about 25 front, 31 rear,
with those pressures and my 175lb frame and Avon Roadriders, I get good traction, handling, and I don't feel every pebble in the road.
With my GS1100E I was experiencing a problem with it going all over the road, especially with a little crosswind, that all disappeared when I dropped the front wheel tire pressure a couple of pounds, now it tracks straight and true, it's nice not having to fight it anymore to keep going straight down the road. What I should've done was look at the manufacturers recommended tire pressures in the first place.

[OldVet66]

I have been using 36 front 38 rear on my bike with Shinko 230 TourMasters. No apparent wear on the front, good feedback and expected wear on the rear. Should be changing the back tire at about a season and a half riding.

[elrico]

On my 83 GS 550 ES I inflate to Suzuki manual and sticker recommendations. Front 16" tyre @ 28psi and rear 18"tyre @32psi. Pressures worked perfectly with Sport Demons installed. Pressures worked when I weighed 200lbs. and still now at 162lbs. I found higher psi resulted in poor grip and harsh suspension action compromising handling.Your results may vary like my weight did

[koolaid_kid]

It all depends on your weight, and more importantly, your riding style. I personally discount recommendations made 30 years ago on tire technology that is now 30 years old. I trust the 10% rule a lot more and it works for me. The 10% Rule
YMMV.

[JEEPRUSTY]

Damn well the tire is on and Noah next door is building a large boat.

Reading the lowdone on the 10% rule now.


Thanks for all the input guys.

[scrapper]

Read the 10% rule but was wondering if justing riding on a mostly straight road would work and about how long would that take. We have a 65 mph state highway road I can ride on. Will that work?

[OldVet66]

I went and applied the 10% rule and adjusted my tire pressure from 36 front 38 rear to 33 front 38.5 rear. I wasn't too far off on the previous guess. I'm running 110/90 front and 130/90 rear tires.

[JEEPRUSTY]

32 cold on my new rear went to 36 warm

not hot but warm and not uncomfortably warm


so I reduce pressure?

[bwringer]

32 cold on my new rear went to 36 warm

not hot but warm and not uncomfortably warm


so I reduce pressure?

No -- 4psi is a 12.5% increase, so you're very close. But you might try bumping your cold reading up a wee bit. Maybe try 33 psi.

Of course, when you're talking about 1psi differences, it's within the error range of most gauges, so 32 is pretty darn close.


As Koolaid noted above, the recommendations on the sticker on the bike were based on tires from ancient history. And the pressure listed on the tires is a maximum, not a recommendation.

The truth lies somewhere in between, and for street riding on modern tires, the 10% rule is an easy and accurate way to find it.

[gsgeezer]

It is amazing how much tyre pressure can increase, when warm.
I just bought an old drag bike and, since I had the front fender off, I noticed that the tyre had expanded to the point that it had rubbed on the bottom of the fender.

[Andrew Vanis]

I trust the 10% rule a lot more and it works for me. The 10% Rule
YMMV.

do you run 10% on front and rear? the article you linked says 10% front and 20% rear - " If the pressure has risen less than 10% on the
front or 20% on the rear, the rider should remove air from the tire"