Progressive Springs - What Do You Think

The bike is getting older and stiffer and so, it appears, am I. I really enjoyed my first season of KZRiding last year but I sure could have used a softer ride. I'm into touring rather than speed and into stock rather moded.

So here's the question(s): Front springs and back springs... are progressive rate springs the solution to my softer ride? Am I compromising anything? What did you buy? Is it worth the money?

Thanks guys.

I wonder if progressive springs are the answer. Maybe lighter fork oil, less preset on the springs if possible or less air pressure in the forks if yours are air forks, and set the shock springs on a softer setting. Running the minimum recommended pressure in your tires could soften up the ride too.

I will be changing the fork oil for sure this spring and I have ordered new seals just in case I damage something in the process.

Good point on the tires. Believe it or not, I have not checked the tire pressure other than to see if they are driveable. These new tires seem to have a very hard tread as compared to what I used to ride and that may make a difference. Thanks.

Your issue is not one of progressive springs vs. non-progressive, but of spring rate. Progressive springs can start out with a softer rate that quickly becomes stiffer, so you need to pay attention to what spring rate you use. Several of the aftermarket spring manufacturers have handy calculator tools to help you decide on a spring rate. Here's a link to Race Tech's calculator =http://www.racetech.com/evalving/SpringRateCalculation/dirtspring.asp?brand=Kawasaki&yr=81-83&ml=KZ1100&formuse=form1&SpringType=Fork]Race Tech

If you think the suggested rate is too stiff, you can try making yourself lighter, or just drop 0.05 in your purchase.

Thanks for the feedback. I am now operating on the premise that I have a number of issues... fork oil that was never changed... springs that have lost their, well, spring... and shocks that have seen a few too many pot holes.

Based on this or more likely because I really wanted to, what I have done since my last post is to go all out... I've ordered variable rate springs for my front forks, variable rate springs for both rear shocks and ,since I was informed they would not fit my stock shocks, I ordered a new set of shocks as well. And oh yah, I bought some fresh 15 Wt shock oil. There goes the budget!

Once I get back from my assignment and I install all of this stuff, I'll get back to this post and provide my qualitative findings. I'll pay closer attention to how to set them for my weight and riding style too.

In the mean time I'm off to see the Pyramids.

Bill
Giza, Egypt

Sorry, I could not open the Race Tech link.

Post edited by: bill_wilcox100, at: 2007/05/26 16:42

I have full Progressive suspension all around my bike and love it. I went with the normal front springs and added 15 weight oil, really stiffend up the front end. And in the back I went with the 14 series Shocks and 2 stages up in the springs, I think they were 140/90's and they are on the lowest preload setting.

With this set up I have barely any nose dive for the turns and on the expressway I think i'm in a Cadillac.

You may want to run 5wt oil in the front as it will soften it up a bit.

Thanks incognito0160. It sounds as if you have already done what I'm looking forward to doing.

The set of rear shocks and springs that I bought are Progressive Spring model 12-1202B. These are the 13 1/2" shocks rated at 75/120 lbs. that Z1 recommends as non-Heavy Duty for my KZ650. The springs are chromed but I the shocks are black which will take away from that stock look I was hoping to maintain. So vanity will have to give way to creature comforts this time. Also, my weight rating is much lower than yours so it will be interesting to see how this turns out. I'll get back to the forum on this.

I bought a can of 15 wt fork oil from a bike shop but after your comments I plan to return it for a can of 10 wt. I don't think that 5 wt in available locally. Thanks for that feedback.

Have a great riding season!