TOO Much Wallow in sweepers

[gixerbike1]

Uhm, I are an Id10T, well i feel like one anyway

Well then don't expect any miraculous changes.

Pos, I really didn't expect any, just a decent ride. some flex is to be expected under a heavy load.

The differences between radial and bias ply tires is very significant.

Oh, I'm fully aware of that, I've had bike's in the past with Bias ply tires and they handled just fine.

I'd say my on my GS750EX which is basically stock but with Progressives and fork brace up front, with Hagon shock in the rear with Avons all around I dont like to do any heavy cornering beyond maybe 60 mph. It runs fine at 85 mph on the straights.

Yeah, I had mine buried past 85 in a straight with no problems.

With my 83 1100ED, with stock 37mm forks, racetech emulators, progressive and fork brace on front with Ohlins piggybacks on the rear and Sport Demons all around heavy corner at above 85 mph are a little scary, goes as high as you want to go straight till the wind knocks you off.

With 18" GSXR conversion 43mm forks (braces, progressive springs, emulators) and radials 170/60-18 back, 110/80-18 front (Dunlop/Avons modern stuff) with SU-145's now much more stable at 85-95 cornering. A little wollering going on and that is likely frame flex starting to have an effect.

Awesome, Sounds like a stout bike to me, lots of love spent on that one I see.

I'm now closer to a modern bike but not there when you compare modern 180/55-17 and 120/70-17 with a real stiff frame.

Anyway, with a GS you can get a thrill at 1/2, 2/3 or 3/4 speed of a modern bike depending upon what you do to it.

And that's about all I really plan to do with it.

Now Let me tell you what i found this afternoon.

I decided to check the air pressure in the tires just for the heck of it, low and behold they had very little.

Now being used to mostly sportbikes where if your tire is low on air, you can dang well see it. Not so much on tires with tubes in them.

My bad all the way round, no pun intended.

Filled the rear to 42 and the front to 36.

OH, And My boy read the tire size off to me wrong, it's a 120/90-18, just one size up from stock. the rim is actually 2.75 inches, Sorry about that.

So, Next i checked the sag.

On the front with no weight on the forks they measure 6.5 inches from the top of the dust boot to the bottom triple tree clamp.

With just the bike itself there was 5.5 inches of fork showing, with me on the bike it dropped another 1/4 of an inch, so total sag was 1.3 inches on the front.

The rear was 22 and 5/8's of an inch from the bottom of the mud flap to the ground with no weight on the rear.

With just the bike it measured 22 and 1/4 inches. With me on the bike it measured out to an even 22 inches.

So, not being an expert on suspension setup is this good or bad ?

Let me know what you guys think about this.

Thanks again,

Tommy

[posplayr]

I watched the TT too. Those guys are amazing. You see how out of shape the bikes get and they stay cool and let the bike settle down. That takes some balls to ride that island the way they do.

I think the OP is seeing a couple of things with the 130 on the rear. Triangular tire shape from being pinched leads to both. This makes the rear resist leaning over and when it does it wants to flop down off the center of the tire. When the bike comes back upright it's more abrupt than it should be out back and the suspension gets unsettled.

Then not only is the sidewall flexing but the contact area while leaned over almost becomes an extension of the sidewall from being misshapen by being pinched too much. The contact area while leaned loses it's rounded profile and gets a little flat compared to what it should be. The transition from tread area to sidewall is flatter, for want of a better word, than it should be. You lose some of the definition between the sidewall and the edge of the tire. Hope you get what I mean here.

Yea, the rear tire/sidewall distortion is not good. The only way you tolerate it is when the front and the rear are doing the same thing but given the differences in profile and loading that is seldom exactly the same.

[Billy Ricks]

Were these measurements taken with the wheel off the ground at each end and suspension fully extended or was there weight on the wheels? The first measurement should be wheels off the ground and suspension fully extended. If you want a very firm, aggressive ride shoot for 1-1 1/4" of sag at both ends with the weight of the bike and you in the seat, wheels on the ground. If you want a firm, sporty ride use up about 1/4 of the full travel. For a plush, lazy ride use 1/3 of total travel for your sag.

[gixerbike1]

awesome Video

Were these measurements taken with the wheel off the ground at each end and suspension fully extended or was there weight on the wheels? The first measurement should be wheels off the ground and suspension fully extended. If you want a very firm, aggressive ride shoot for 1-1 1/4" of sag at both ends with the weight of the bike and you in the seat, wheels on the ground. If you want a firm, sporty ride use up about 1/4 of the full travel. For a plush, lazy ride use 1/3 of total travel for your sag.

Hey Billy,

Those were with the wheels off the ground and no weight on them and the suspension was fully extended. I'm shooting for a sporty ride, kinda good all around.

Great Video by the way thanks

So, with about 5/8's to 1 inch in the rear and 1 and 1/4 up front what are your suggestions ?

Thanks,

Tommy

[Billy Ricks]

Hey Billy,

Those were with the wheels off the ground and no weight on them and the suspension was fully extended. I'm shooting for a sporty ride, kinda good all around.

Great Video by the way thanks

So, with about 5/8's to 1 inch in the rear and 1 and 1/4 up front what are your suggestions ?

Thanks,

Tommy

That was Jim's video.

The front measurement sounds good. Do you know what the travel is on the rear shocks? I would think probably about 4" at the shocks themselves. If you're unsure of that then take a measurement from somewhere straight above the axle to the axle itself. Take your sag measurement between the same two points. Again, with your weight in the seat. I'd set that up at about an inch as well as see how it feels. Run it as stiff as you can without introducing pogo effect after hitting bumps. I doubt you have damping adjustment so you won't be able to address that.

[Billy Ricks]

Once you get your sag set up for your weight then move to tire pressure. Go for a 10% rise in pressure cold vs hot. I think it's been talked about already in this thread. If not check your pressure on stone cold tires. Then go for a ride. You want to push the tires hard for at least 15 minutes. Check the pressure again. You want to see a 10% increase.

Once you get this done then you can start fine tuning the sag at both ends. Keep them proportional to each other. You're kind of stuck with spring rate and damping on the rear. Up front the spring rate and damping can be played with in a couple of ways if you find it doesn't suit you. I think what you've done to the forks will work pretty good for you with 1 1/4" of sag.

[Sandy]

A zip tie on each fork tube is a great way to see exactly what your suspension is doing. Set one at the top end of the travel where the suspension bottoms out and use the other to gauge how close you come to bottoming under different riding conditions. This one you will move around as you play with your settings and can also be used to help measure the sag. My personal preference is set the right hand one where the suspension bottoms and use the left one to see what's happening. This way on a naked bike you can actually move left one back down the fork tube while riding and not have to let go of the throttle. One critical thing to watch, and this is where the zip ties come in real handy, is to see how close to bottoming you get under extreme braking. You want to come close but not actually bottom out. Hope you don't get to confused with all this information overload, but once you start testing it will all make sense. It just takes some patience and a methodical approach and when you get close only do one adjustment at a time.

[posplayr]

http://www.thegsresources.com/_forum/showpost.php?p=994640&postcount=7

I dug up an old thread (only 1 year ago when I was struggling with same).

Ohlins suggests:

-------------F-------------R------
Static-----15-30--------10-20----mm
Laden-----35-50--------25-40----mm

These need to be adjusted based on total stroke; the old GS's have longer stroke up front so make adjustments accordingly.

I used your numbers and here is what I get:

-------------F-------------R------
Static-----25.4--------9.5----mm
Laden-----32----------16-----mm

The other thing to do is make sure you bounce up and down a little to reduce "culomb friction" effect. But assuming your numbers are accurate. You can average the numbers (first6 on teh front and then on the back) measured by
a.) pushing down and letting up and
b.) lifting up and letting down to get a more accurate average.
c.) average there two numbers (for all 4 static/laden and front and rear)

From the numbers (Front laden) you have. The front is stiff but passable. If your springs are stock and not cut down then I think you need to remeasure that. Sprinsg are usually worn out and soft.

From the (Front static) you need more preload to drop that number a bit. Again check your meaurements with an average.

From the (rear laden) number your rear springs are too stiff.

From the (rear static) number the rear preload is high but passable.

That is at least what is indicated.

If you find your manual and check what the stroke is front and rear and then use Billy's numbers 1/4 full travel (for firm ride) F/B to recalculate to see what you need for laden sag.

Then use the Ohlins guide to get static sag or even just ride quality.

I'm starting to suspect (guessing a little here) you have a very stiff rear and need to bring the front more into line even if it ends up being a little harsh up front to get in balance with the stiff rear.