Tire Pressures?!?

[mmattockx]

Looking for some advice/experience/thoughts on tire pressures with modern bias ply tires. The bike is an 82 1100E. I installed a set of Shinko 230's a couple of days ago, tubeless on both ends. 100/90 front and 130/90 rear. Set the tire pressures to 32F/34R and did one quick test ride to check the installation and scrub some release compound off. They felt OK, with a bit less stability around center than the BT45's they replaced but I didn't go far enough or hard enough to tell much more than that. I mostly ride solo, usually semi-spirited street riding.

I used to run the BT45's around 36F/38R or a bit higher but that now seems too high to me after years of radials on modern sport bikes. What do other people run for pressures? What is deemed too low or too high? Symptoms of being too low or high? Does anybody go down to 30psi or less for street use?


Mark

[Nessism]

You should be okay at those pressures. If you really want to go wild look up details about the 10% rule...http://www.thegsresources.com/_forum...rule-revisited

[76_Mike_82]

I'm running the same tire front and rear on my 850 the dealer (Ironpony) told me the shinkos like to be around 40 front and 42 rear. I ran that on my trip last week (1700miles) without any issues. The rear tire is the second one I've had. I got about a year out of the first, sadly I don't know how many miles that was I didn't record the install milage. But it was kept at 38psi. I was hoping to get more than a year out of it since I generally get a year out of my Busa and I know the 850 isn't putting nearly the power to the road as the Busa.
Hope this helps some.

[Rob S.]

I think I'm running about 30f/36r right now with fairly new Pirelli Sport Demons. But I'm not as brave as you - I'm running tubes. Why? "That's what the stock wheels were designed for," according to my mechanic.

You running the stock '82 11e 'snowflakes'?

[mmattockx]

You should be okay at those pressures. If you really want to go wild look up details about the 10% rule...http://www.thegsresources.com/_forum...rule-revisited

Thanks, Ed. I'm not completely sold on the 10% rule for street use. It was intended for track tires being used on the track and works fine there, but street riding never gets the tires hot and keeps them hot like the track does.

I'm running the same tire front and rear on my 850 the dealer (Ironpony) told me the shinkos like to be around 40 front and 42 rear. I ran that on my trip last week (1700miles) without any issues.

You shouldn't have any issues with pressures that are on the high side, all that does is give up some traction as compared to lower pressures. I am most interested in how low people have gone and what they think of it. On my 06 GSXR1000 the front end gets twitchy on the street if I get much below 30psi, but running 28F/28R works fine on track days in our moderate Alberta temperatures. Does anybody have any comments on the symptoms of low pressure on their GS with bias ply tires? Do they also start to get unstable? Wallowy? Something else?

I think I'm running about 30f/36r right now with fairly new Pirelli Sport Demons. But I'm not as brave as you - I'm running tubes. Why? "That's what the stock wheels were designed for," according to my mechanic.

You running the stock '82 11e 'snowflakes'?

Yep, stock wheels. My reasons for going tubeless are:

1) The tires are designed as tubeless.
2) The rear wheel is designated 'tubeless' and marked with the correct MT profile designation for running tubeless tires, so it is perfectly OK to run tubeless on.
3) The front wheel is not marked as such, but I know lots of people here have done it without issue. I did have a tube ready as back up in case we couldn't get the bead to seat properly but it gave no trouble and seated fine.
4) It saves unsprung/rotating weight, tires run cooler and gets away from the explosive deflation mode that tubes typically have.

So far, so good...


Mark

[850GT_Rider]

I'm running the same tire front and rear on my 850 the dealer (Ironpony) told me the shinkos like to be around 40 front and 42 rear.

That's about what I run on the Shinkos on my heavy-ass, Windjammered, luggaged, mostly two-up 850. Front end get twitchy real fast if it's below 38-40 psi cold.

[76_Mike_82]

That's about what I run on the Shinkos on my heavy-ass, Windjammered, luggaged, mostly two-up 850. Front end get twitchy real fast if it's below 38-40 psi cold.

I'm like you, my 850 is fully loaded, vetter fairing, stereo, full luggage. But I've never felt it get squirrelly. I stay onbmy tire pressure, seen too many blow out on due to low pressure.

[mmattockx]

Just an update and another question on the Shinko 230's.

First, the update. I have been out for a couple hundred km's now on a couple nice days. First ride I went with 30F/35R after some PM discussions with a couple members here. It felt OK and handling around center was good but turn in was slightly twitchy. Second ride I went with 30F/32R because I am just not sold on having such a big pressure difference between the two and I didn't seem to be using much of the rear tire. I liked this better and turn in was less twitchy and felt more predictable. I will probably stay here for a while and see what I think of it with more miles. If I am going to ride two up I will run the rear back up to 35psi to compensate for the passenger weight.

Now the question for those with 230 experience: Which tire gets to the edge first? I am now used to wide radials on modern sport bikes and the rear always gets scrubbed to the edge first and the front always has ~1/4" wide chicken strips that never get touched, at least with me at the controls. The 230's on my 1100E are looking like the front will be scrubbed to the edge first and a small chicken strip remaining on the rear. Is this normal for these?


Thanks,
Mark

[alke46]

I'm running 32F and 36R and have had no issues with feel. This is also where the 10% increase landed as I did several different pressures before settling on the 32/36.

[Joe Garfield]

I've got Shinkos on my 1100g. If I get too much under 30psi on the front, the bike turns like a pig. 30+ and the turning is much quicker. I don't notice that from the rear, but I do notice less traction over 30psi. So I like 34F/30R.

[nejeff]

I run what it says on the tire. Shinko 230's is what I am running on my GS850

[nejeff]

Is there a reason to not run what it says on the tire?

[mmattockx]

I run what it says on the tire. Shinko 230's is what I am running on my GS850

Is there a reason to not run what it says on the tire?

All it gives on the tire is the maximum safe pressure, it says nothing about an optimal tire pressure. You have to find that on your own as it varies between bikes and riders. If you are running at the maximum rated load then you would want to run the max pressures. At lesser loads lower pressures will perform better and that is what I am looking for. The reasons to run less than maximum are improved handling and more traction. So far I am happy with the 30F/32R and am sticking with it for the moment.


Mark