Shinko 230 Tourmasters

[OldVet66]

I installed a set of Shinko 230 Tourmaster tires on my bike today. Heavy duty tubes and Dynabeads. I have always used a 130 rear with a 100 front, but this time I went with the 110 front. It did exactly what I was hoping it would do. With the 100 it would always feel like the front would fall into a turn immediately and the rear swing way out and around to line up with the arc of the turn. Kind of twitchy, but not bad. With the 110 matching size better with the 130, the fall and swing seems to match more equally and feels more natural. I couldn't find any pressure recommendations, except at the Shinko site mentioning 41lbs. The ten percent rule won't work, because I filled the tires with nitrogen, so there is no pressure increase with heat. To tell the truth it feels very smooth and stable at 41lbs. even though they are still breaking in. I'm 180lbs. and I have saddle bags and a backpack on the bike at most times, weighing in at about 50lbs. Any recommendations would be appreciated. I can always let some out but I don't want to use up all my friends nitrogen tank finding the right pressures.

[7981GS]

Same tires and sizes at both ends, same body weight as you and the only difference is on a '82 1200G.
I run 36 on the front and 38 on the rear.
Two-up, we run 38 on the front and 40 on the rear...




Hope that helps.

Eric

[7981GS]

I had forgotten so I went out to check,
Same sizes, same rider, BT-45 on the front and 230 Shinko on the rear of my '81 GS1100EX also.



Same pressures.
Again, hope that helps.

Eric

[OldVet66]

So if you fit the 10% rule you are doing 39 front, 41 rear with a hot tire. I never have room for two up, so dropping two lbs in the front would match assuming I don't dilute my nitrogen too much.

[7981GS]

In the winter, when it is below 45 as a daytime high, I drop a couple pounds front and back.
That's about it.
And yes, I check my tires EVERY week.

Eric

[OldVet66]

Thanks, I'm in the ball park. If I can keep running nitrogen and can schedule when my friend checks his tires, I won't have to bug him to set up the tank regulator when I need a little, and won't have to worry about temperature with an inert gas.

[tkent02]

Thanks, I'm in the ball park. If I can keep running nitrogen and can schedule when my friend checks his tires, I won't have to bug him to set up the tank regulator when I need a little, and won't have to worry about temperature with an inert gas.

The Ideal Gas Law applies to nitrogen as well as air.

[OldVet66]

Well I've been wrong before, what are your recommendations, or does the same apply as with air. I take it the 10% rule does apply.

[OldVet66]

Changed the pressure to 36 , 38. I like the way these tires ride.

[Griffin]

Nitrogen (henceforth known as N2) filled tires will increase in pressure as temps rise, as will those filled with air. Using the 10% rule will get you the same results.


This is as good a place as any to clear up the misconceptions sorrounding N2 in tires as any. I work in the compressed gas industry, use ideal gas laws all the time when designing systems, and also design systems implementing various designs and technologies to lower pressure dewpoints in compressed gas.

The benefits from N2 filled tires aren't due to the fact that it is only N2, and not air, in the tires. Atmospheric air is 78% N2, 21% Oxygen (O2), 1% Argon, and the rest are trace gases. So the compressed air you get from a compressor is already overwhelmingly N2.

But it also contains water vapor. That is the key difference between "nitrogen filling" and "air filling".

When air is compressed, there is a lot of heat generated in the process. You are compressing everything in the sorrounding air into a much smaller space. That includes the water vapor molecules in the air. Because these water molecules are much closer together after compression, they form water droplets and become a liquid. The air you get out of a compressor is completely saturated with water, and hot. If there is no type of dryer between the compressor and the air chuck, then water, as well as air, goes into your tires at an elevated temperature. That is not a good thing, but it's been going on for over 100 years.

Now then, in order for the N2 generator to separate N2 from the compressed air, the air has to first be cooled and dried. N2 generators implement an aftercooler and a desiccant-style air drier which lowers the pressure dewpoint (the temperature at which liquid water drops out of the air) from saturated (100% relative humidity) to -40 degrees F (0.52% relative humidity). At 100 psi (the pressure most compressors feed N2 generators at), that translates to one water molecule for every 7,900 N2 molecules. By comparison, what you're getting out of a gas station air compressor has one water molecule for every 42 of the various air gas molecules.

If every gas station or tire shop had an aftercooler and desiccant air dryer with no N2 generator, there would be no real world benefit to using N2 in tires. But for marketing purposes, "Nitrogen filled" is an easier concept to grasp than "negative 40 degree dewpoint air filled".

[7981GS]

Changed the pressure to 36 , 38. I like the way these tires ride.

They feel almost exactly like riding on the Pirelli Sport Demons.
From what I have heard from a trusted friend, they last longer than them also.
Head out to Skyline Drive with them.

Eric

[OldVet66]

I used Dynabeads. The Valve stems didn't want to take the beads, but I finally beat them into submission. They run extremely smooth. This civil behavior is going to take some getting used to. With the 100 in the front, you could sneeze and flick the bike. I liked that except when riding at speed any buffeting would translate to handlebar input, it bugged me constantly. With the 110, that behavior is completely gone and much more suited to long tours. The bike feels a lot heavier, but more predictable.

[Steve]

...The tire has easily another thousand good miles remaing.....but has had 6,500 plus miles roll under it. ...

May I ask what kind of mileage you are accustomed to getting on a tire?

I was rather bummed out when we had to change the tires on my wife's bike at 12,000.

"Bummed out" because I routinely get over 20,000 on my Wing.

.

[Steve]

What tires are ya running on your wife's machine?

Had two sets of Chen Shin Hi-Max tires on there before they were discontinued.

Put on the Shinko 230s before our trip to West Virginia in May, just don't know what kind of life to expect out of them.

By the way, the tires on the Wing were: three sets of Dunlop E3, and I am currently on my second set of Michelin Pilot GT. The first two sets of Dunlops were changed at about 23,000, the third was changed at about 20,000, but only because I was headed out with no idea for how long, so I changed them early. The first set of Michelins were changed at about 18,500, again, they were early due to an upcoming trip that would probably run them to cords.

.

[OldVet66]

After A few days with these tires I have to say this combination is the best I have had on my bike yet. I can only conclude that going up one size on the rear only is a mistake. Going up a size front and rear took some getting used to, but I can tell already that handling and confidence have improved greatly and it is due to a better balance between front and rear sizes. Now I will see how they wear.