Work Out Suspension Setting In Totw2 Dvd

[ozfireblade]

After completing level one I am now firmly hooked!! I also want to improve my technical knowledge starting with suspension.

 

I suppose the first question I have is regarding the initial setting up of the bike; ie sag, front and rear settings. In TOTW2 dvd the bonus SAG feature cleared up how to make the adjustments; however, I dont understand how the rider came to his decision to adjust 30mm front and rear. Was this just a figure to show how to make the adjustment or is there some way I can work out my initial settings?

 

My bike is adjusted to the basic factory settings with the odd tweak to make it a bit stiffer,CBR 1000 2005

 

Thanks

 

Dylan

[Sof]

After completing level one I am now firmly hooked!! I also want to improve my technical knowledge starting with suspension.

 

I suppose the first question I have is regarding the initial setting up of the bike; ie sag, front and rear settings. In TOTW2 dvd the bonus SAG feature cleared up how to make the adjustments; however, I dont understand how the rider came to his decision to adjust 30mm front and rear. Was this just a figure to show how to make the adjustment or is there some way I can work out my initial settings?

 

My bike is adjusted to the basic factory settings with the odd tweak to make it a bit stiffer,CBR 1000 2005

 

Thanks

 

Dylan

 

Hey Dylan,

 

I hope you're well. From what I understand about setting the rider sag, 30mm is pretty much a standard number used for the spring to feel not too hard and not too soft, but it's all personal preference. It might be 25mm for a rider who likes it a bit harder for the track. The bike's preload settings to get the rider sag to 30mm will be different for each person because the weight of the rider+gear. If the rider sag is less than 30mm, then the spring will feel harder, and if more than 30mm, it will feel softer. So if your bike is set up for a 60kg racer and the rider sag is 30mm, when someone 100kg sits on it, I'd imagine the rider sag would increase quite a bit to say 45mm (just a guess) because of the extra weight. So the preload would have to be increased to get the rider sag back to 30mm for the 100kg rider. If the preload is at its maximum setting, but the suspension is still too soft, you would need a harder spring to get the desired 30mm. Did I get it right and does that make sense?

 

Once the preload is adjusted properly for your weight to get the standard rider sag of 30mm or thereabouts, you can play with the other settings like rebound and compression. I hope you have fun with it

[ozfireblade]

After completing level one I am now firmly hooked!! I also want to improve my technical knowledge starting with suspension.

 

I suppose the first question I have is regarding the initial setting up of the bike; ie sag, front and rear settings. In TOTW2 dvd the bonus SAG feature cleared up how to make the adjustments; however, I dont understand how the rider came to his decision to adjust 30mm front and rear. Was this just a figure to show how to make the adjustment or is there some way I can work out my initial settings?

 

My bike is adjusted to the basic factory settings with the odd tweak to make it a bit stiffer,CBR 1000 2005

 

Thanks

 

Dylan

 

Hey Dylan,

 

I hope you're well. From what I understand about setting the rider sag, 30mm is pretty much a standard number used for the spring to feel not too hard and not too soft, but it's all personal preference. It might be 25mm for a rider who likes it a bit harder for the track. The bike's preload settings to get the rider sag to 30mm will be different for each person because the weight of the rider+gear. If the rider sag is less than 30mm, then the spring will feel harder, and if more than 30mm, it will feel softer. So if your bike is set up for a 60kg racer and the rider sag is 30mm, when someone 100kg sits on it, I'd imagine the rider sag would increase quite a bit to say 45mm (just a guess) because of the extra weight. So the preload would have to be increased to get the rider sag back to 30mm for the 100kg rider. If the preload is at its maximum setting, but the suspension is still too soft, you would need a harder spring to get the desired 30mm. Did I get it right and does that make sense?

 

Once the preload is adjusted properly for your weight to get the standard rider sag of 30mm or thereabouts, you can play with the other settings like rebound and compression. I hope you have fun with it

 

Makes sense but how do I as a novice come to the conclusion of eg 30mm? You make perfect sense I just need that little question answered.

 

Thanks mate

[Fajita Dave]

You just have to try it. A rider is going to like different settings for their individual riding style. As you ride more you'll find what you like and don't like. The first time you make an adjustment its kind of a shot in the dark. You know its going to feel a little stiffer or softer, might feel a whole lot different under braking but you wont know if you like it until you try it.

 

I just checked the sag recently on my 08' gsxr600. The front was around 45mm and the rear was at 25mm (kind of weird right?). I cranked the front preload all the way down until it wouldn't go any further and it came out to 30mm of sag and I only weigh 140lbs. I left the rear as it is. I did this because I was going to go to a track day in October but it was full anyway . So I haven't tried it on the track yet but just riding around on the street the braking is so much nicer! The front end doesn't dip anywhere near as much under braking and I have a bit more feel while doing fast transitions. Compaired to the preload now it just felt sloppy before.

[GregGorman]

I'm probably a little wrong here but I'll chime in anyway.

 

My understanding is the primary reason for sag is so the shock absorber (fork or rear shock) doesn't top out on rebound. Should it top out the bike will feel very harsh and loose as it bounces across the pavement.

 

Tuning reasons for adjustment are ride height and feel.

 

So for a basic setup, because most bikes have about the same about of travel, just starting with 25-30mm sag rear and 30-35mm sag front is a good place to start.

 

The real vague part of my understanding is that adding preload doesn't change the rate of the spring. Once the spring is moving, it requires the same amount of force to compress the spring 1mm/sec regardless of how the preload is set. But, what does change is the initial amount of force required to get the spring to start moving. Weird physics stuff relating to the change in the coil of the spring.