WARNING: More Motorcycle Content

Has anybody ever been in a situation where they were tempted to
*reduce* air pressure in their tires for comfort during a ride?

The recommended minimum air pressure and suspension settings
in my Yamaha FZR1000 owner's manual don't work for me.

The area I live in has rather extreme temperature variations which I
doubt ever occur in Japan where the test riders must have
determined the recommended settings.

It can be 55 degrees in the morning here and I set my rear tire
pressure to the minimum 36 psi recommended by the manual.

I have the rear suspension preload backed off almost to the minimum.
Backing off any more will result in bottoming.

By midafternoon, the temperature is up around 100 degrees and the
pavement temperature has to be at least 120 degrees.

The rear tire pressure rises to 40 psi and the motorcycle becomes a
torture rack over the roughly paved county road that is the last 20
miles of my route.

I was riding slowly along the bumpy back road yesterday when I saw the
lights of a bunch of Harley riders behind me, so I moved to the right
and let a dozen bikes pass me.

They were riding twice as fast as I could go, and I suspect that
their balloon tires and softtail suspensions made for a much more
comfortable ride than my sporty bike.

I wonder how much air pressure Texas Harley riders use in their back
tires, during hot weather.

 

Wrong.

Try different tyres.

 

Instead of just backing off preload, adjust compression and rebound too.
Or buy some good suspension bits...it is amazing how much better the good
aftermarket rear shocks are.

 

Not adjustable.

That's not in the budget for this fiscal lifetime...

 

You do realize that you can reduce your tire pressure to 36psi after
it has risen to 40psi, right? You do know that different tire guages
give different readings, right? And you have checked yours to see
that it is not reading 10 or 15% low, which is very common, and could
mean that you are riding around with 44-46 psi in your rear tire once
it comes up to operating temperature, right?

I know an experienced rider like you, riding a liter sportbike, knows
all this already. I'm just mentioning it because you did not mention
it in your whine^h^h^h^h^h post.

This is not a surprise in any way.

Softtail suspension is notorious for its short travel, harsh spring
rates, and poor damping. I suspect that they simply are much more
accomplished, capable, comfortable riders than you are.

Why would you wonder that? It has nothing to do with your problems at
all.

 

Then get a real job.

 

There's also a reason why tyre and bike manufacturers recommend checking
tyre pressures when cold. It's because they *know* that the pressure
increases as the tyres warm up, and factor that it.

 

Or any job ;-)

 

Fill your tyres with nitrogen.
The pressure will not increase so much as they heat up.
Not that it will make any difference....

 

It's a little late now, but I always stock up on spring air. Rides
better than the dead, overly humid summer air. Winter air you have to
be careful with since it freezes easily. Use fall air and you'll come
out one day to see it's come off the side stand.

If they're running hot, try using freon. Just be careful to put it in
on the low pressure side or the can will burst!

 

Of course I realize that I can reduce tire pressure when it's hot and
has risen.

However, doing so defies the "conventional wisdom" of decades of
published advice to the contrary.

Whatever a pencil type air pressure gauge reads is just a reference
point and a rider should treat it as a personal accessory like his
favorite tooth brush.

But I did buy two extra tire gauges and compared their readings to the
one I already had. I kept the two gauges that agreed with each other
and threw away the one that read too high.

So maybe the more flexible sidewalls of their balloon tires make for a
more comfortable ride?

Quien sabe? I still got back to Cowpoop City before them, because they
stopped and milled around like a confused convoy twice in twenty
miles.

Because it gets even *hotter* in Texas during the summer than it gets
here.

 

And I suspect that the daily temperature variations in Japan are far
less extreme than they are here in California's central valley, where
the temperature might change over a range of 60 degrees F in six or
seven hours.

So the advice in a Japanese owners manual might reflect less extreme
conditions.

 

The reason for using nitrogen to inflate tires is that it is a *dry*
gas and the pressure won't increase so much due to the vaporization of
*water* when the tires get *really* hot.

The first time I ever saw nitrogen used to inflate tires was in an
aircraft tire shop.

Aircraft tires get so hot during landings they are an explosion hazard
to ground crew placing wheel chock once the aircraft is parking.

 

****, but you're stupid. Let's see if you can recognise the bleedin'
obvious, shall we.

<fx: Counts>

One, two, three......

 

Isn't it also true that Japanese tire valves are narrow and
slanted, unlike Caucasian tire valves ? I read that someplace
on the internet.

 

Hmmm, that's a shame as I thought the suspension on the Road King was
pretty damn appropriate for its mission. Guess one needs to ride them
all...

 

In which case simply bleed some of the excess air out of your tire and
see if the ride is more comfortable. How freaking hard would it be
to try that, for a big time mile eater like you?

 

The FLH touring bikes do not have Softtail suspension.

 

Never use nitrogen in motorcycle tires.....ever. This is critical. Tire heat is essential for maximum traction. Bike tires filled
with nitrogen stay too cold. I have followed this thread and like most of you, have found some of the statements made by the
originator a bit short of credible. First, unless this fellow weighs 400 lbs, the suspension won't bottom out on any setting.
Nobody has asked how heavy this guy is. Setting up a suspension preload is stupid simple. Most of the readers here know how to do
this, so I won't bore the readers with these directions. They can be found all over the net and in his owner's handbook. He needs
to use the tire manufacturer's pressure range period. I am relatively certain the guys that made his tires know considerably more
than he does about his tires. Please keep in mind his tires performance is almost as important as the space between his ears in
preventing a really bad day. I suggest he owns the wrong bike. Sportbikes are not mile eaters. They are performance machines. if
he wants a mile eater, he should buy one. These are two completely different roles that cannot be performed by the same machine. I
have a Road King, a street legal Buell 1125r and a race only 1125rr just for that reason.
Steve

The reason for using nitrogen to inflate tires is that it is a *dry*
gas and the pressure won't increase so much due to the vaporization of
*water* when the tires get *really* hot.

The first time I ever saw nitrogen used to inflate tires was in an
aircraft tire shop.

Aircraft tires get so hot during landings they are an explosion hazard
to ground crew placing wheel chock once the aircraft is parking.

 

How much air should be bled and what's the
correct torque for the valve caps ?