fork springs - another progressive upgrade

I got the recomended progressive springs for my 83 KZ550-C4.

Old springs are 24" and new ones are 19". Does that sound right? I'll end up with 5" of PVC and some washers. It sounds like a huge difference to me.

Thanks in advance.
-charlie

After getting the wrong PVC pipe-1" I was thinking that machining from this place would be a better option:

www.emachineshop.com/

It would be a cheap part it is just that machining setyup is $150. Maybe jeff at z1 or other folks may be interested to help split the cost.



Anyone?

I gues this will turn out to be a diary which is fine, but I am sure there are experienced folks that have opinions about this.


I ended up with 3/4" dia. PVC spacers at 6 1/8" lenth which puts them at about 1-1.5" of preload. Which may be too much.

Wow! the first ride was great and felt the front suspension doing what it should do -absorbing the bumps. Steering was much more controllable too. I am guessing long distance breaking will be better (no more running yellow lights for fear of locking up?)

The only thing is that big bumps and manholes I feel the front suspension bottom out. too much preload? too little spring? (new springs are 5" shorter)

Can someone comment on this? Maybe the stock springs sould be better with some spacers for preloading since there were no spacers before.

I upgraded the fork springs in my Concours and went with Sonic springs - it was the same way, in this case 6.5" of pvc but they work great.

Do you recall how much preload theer was? I am concerned about the hard bumps at high speed. Do you notice a bottoming out on hard bumps?

Well, I took to the haighway and some of the hartsher bumbs ad high speed felt dangerous. I felt the front hit the bump and bottom and the wheel felt like it was all over the place.

My friend suggested puping some air in them. But I was thinking less preload.
-Anyone got an idea?

Post edited by: guavatone, at: 2007/07/11 15:13

what weight oil are you running in the forks?? you could go thicker or higher viscosity before doing anything else. this would help with damping somewhat...steve

7.5 from the nke shop with a little 10W40 to top that off. maybe 3 parts 7.5 to 1 part 10. There is definitly oil on my forks from slight leakage though.

The preload in the shocks is necessary to keep the springs from finding air inside the fork housing. I think about 1.5" of preload PVC is about right. The washers are there to keep contact between the springs and PVC from cutting up the PVC. I had a Vulcan I used shorter than stock springs on and cut the preload PVC down to about 1/2" to lower the bike. The bike road OK until I hit a bump and the springs extended... without the preload, there was a big KLUNK as the shocks opened to their max... I ended up putting longer preload spacers in even though it raised the bike a tad... Was going for the spiffy dropped look (I was younger and dumb).

The preload in the shocks is necessary to keep the springs from finding air inside the fork housing. I think about 1.5" of preload PVC is about right. The washers are there to keep contact between the springs and PVC from cutting up the PVC. I had a Vulcan I used shorter than stock springs on and cut the preload PVC down to about 1/2" to lower the bike. The bike road OK until I hit a bump and the springs extended... without the preload, there was a big KLUNK as the shocks opened to their max... I ended up putting longer preload spacers in even though it raised the bike a tad... Was going for the spiffy dropped look (I was younger and dumb). The 7 wt oil is a bit thin... depending on how much you weigh. I use a bit heavier oil in my shocks; generally 12W

Thanks George it always makes me to see your comments on my post. I am 200-210 lbs. I actually didn't use the washers. MaybeI'll try 15W since i don't think I can find 12W. While I;m at it I may try to use smaller spacers with washers this time,