Front suspension springs poll, what are you using?

[burning1]

I would at least do the springs and oil. $150 isn't much, especially since your safety is on the line. Also, a properly tuned suspension tends to make the tires last longer.

[RichDesmond]

Same length as stock.

My setup right now:

1. .85 springs
2. Stock preload (about 30mm, IIRC)
3. Emulators (factory preload, spring, and low speed bypass holes.)
4. 15 weight fork oil
5. Fork oil level set to 100mm

The fork oil level is set extremely high, in order to prevent the forks from bottoming out. It makes the spring rate quite progressive. I've found I cannot bottom out the forks by hand.

Dang, that's a lot of preload. What are your sag numbers?
A more normal setup for your weight would be 0.90 (or maybe even 0.95) springs, 15mm of preload and an oil level in the 115-125mm range.

[burning1]

The forks are no longer on the bike, so I can't measure. Sag is about spot on. Actually, I think I had to add about 2mm more pre-load than stock.

I started at 120mm of fork oil, which worked fine at my old pace at button-willow, but it wasn't enough to keep the forks from bottoming out at a faster pace. I found that 100mm was absolutely the highest I could go with Racetech springs, without bottoming out.

The GS now has GSX-R forks with .90s and fresh fluid at the stock level. I'm still bottoming out, so we'll probably have to raise the level by 10-20mm.

[jfoley]

I'm getting the impression that the progressives are for commuters/touring/spirited weekend riding and the straight rate springs (race techs/sonics) can do the same, but are more speed focused. The only difference between stock and progressives is that the progressives will prevent you from bottoming out?

[burning1]

I'm getting the impression that the progressives are for commuters/touring/spirited weekend riding and the straight rate springs (race techs/sonics) can do the same, but are more speed focused. The only difference between stock and progressives is that the progressives will prevent you from bottoming out?

All forks are progressive. That the primary compression spring is actually 2 springs; a coil spring and a pneumatic spring. The pneumatic spring is created by setting the oil to create a fixed volume of air, and sealing the fork. The higher the oil level, the stronger the 'air spring' becomes. This setting has a huge impact on bottoming resistance, but really only affects the spring at the end of travel.

A progressive spring is one that's dual wound. There are two main problems with a progressive spring though... First, it completely changes the rules of sag and pre-load... Static sag that's correct for a straight rate spring is likely to be completely wrong for a progressive spring.

Second, if the two spring rates aren't properly engineered, it can result in some very wonky behavior from the front end. With a progressive spring, the softer, more tightly wound spring is only functional part way through the suspension travel. When the progressive part of the spring is compressed completely, it reaches a state called coil binding, where it becomes a solid mass. When the progressive spring binds, any further compression will be controlled by the stiffer, less tightly wound part of the spring, causing the spring rate to increase dramatically.

[burning1]

Actually, as pointed out with a little research, a 'progressive spring' isn't actually progressive; it's dual rate. The initial rate is the combination of the softer and the firmer spring together. The second rate is created when the softer coils bind, and all of the spring action is handled by the heavier primary spring. So, in essence you're creating a suspension that has dramatically different behavior depending on where it is in the stroke, and a fairly abrupt change.

Since damping rates are generally tuned to match the rate of spring, this is going to create all kinds of problems for your suspension person.

[Nightdrive89]

Heyy burning srry it took a bit but i finally got a chance to throw a zip tie around a leg, i measured 3.4" with my weight on it. that sounds about right, i tend to ride it pretty hard. im 130 lbs without gear. Just to reitterate im running .85 kg/mm racetechs w/ 15w bel ray synthetic and 22mm of preload (the green stuff) Hope it helps =]

[burning1]

That's actually not too surprising. 3.4 inches works out to 86mm, which is a little short of the full suspension travel of the GS. But, if it's comfy to you and the tire wear is good, no problem.

FWIW, I've been going by Racetech's recommendations, which seem to be far on the soft side of things.