Springs and/or fork oil?

Guideon72
03-29-2005, 12:54 PM
Alright. Can someone please explain to me what effect changing one's fork oil and adjusting the preload on the suspension has on the way the bike rides? My front end feels very "squishy", especially during hard stops and in long turns. I would like to do something to firm this up but I need to know what characteristics are affected by those changes. Maybe a little about front springs in relation to this also. Thanks guys! :bluemc: -G

jeeps84
03-29-2005, 12:59 PM
New oil will help the squishy feeling. Adjusting the suspension for your weight always helps the way it handles and stops. What do you have? You may need to upgrade the suspension.

Guideon72
03-29-2005, 01:10 PM
'05 SVS. I'm 5' 10; 190lbs. What is the "preload" then? Is that the "adjusting the suspension to your weight"? Thanks! :bluemc: -G

jeeps84
03-29-2005, 01:15 PM
'05 SVS. I'm 5' 10; 190lbs. What is the "preload" then? Is that the "adjusting the suspension to your weight"? Thanks! :bluemc: -G You need new spring up front. :2cents: I have not ridden a 05 yet. Sag is adjusting for weight. (the amount the suspension drops when you set on the bike.) And yes!

jeeps84
03-29-2005, 01:18 PM
You may be able to upgrade the oil but it will very little change. :2cents:

Guideon72
03-29-2005, 01:19 PM
Thanks Jeeps :) I have to take her in for her first service on Sat, can they adjust the sag for me there? How would I go about that on my own? I will look into some new springs then. I was sort of suspecting that to be the case anyhow, so you just confirmed that for me ;) :bluemc: -G

jeeps84
03-29-2005, 01:26 PM
That is the biggest complaint about the SV's. If you are 100 to 150lb's they are fine for everyday ridding. The heaver riders are the ones that complain the most. Suzuki missed the mark on this and I cant believe they haven't addressed it yet. Other wise its a great bike. :2cents: :twfrox: There are others on this forum that are much more knowledgeable about this than me so good luck.

Gas Man
03-29-2005, 09:56 PM
I don't know about the specific problem on that bike but you could probably get by with changing your fork oil to something heavier and/or changing out the valve... but of coarse you need to set the sag and the other settings first! Then look into some other upgrades...

Guideon72
03-29-2005, 09:59 PM
My mechanical knowhow pretty much stops at changing the oil...How do you set the sag? I'm thinking about changing the oil out to a 15w for now and then upgrading to some .95kg springs + 20w when I've got some money together and after I get my sliders. :bluemc: -G

twisty
03-29-2005, 10:20 PM
That is the biggest complaint about the SV's. If you are 100 to 150lb's they are fine for everyday ridding. The heaver riders are the ones that complain the most. Suzuki missed the mark on this and I cant believe they haven't addressed it yet. Other wise its a great bike. :2cents: :twfrox: There are others on this forum that are much more knowledgeable about this than me so good luck. Most people that know anything about the SV swap the forks for the GSXR 750 forks and respring them for your weight. Adding heavier fork oil will not get as close to the baseline for your weight as getting the correct springs in there will. I was reading it might fix a 10 pound difference but if you weight 200 and the forks are set for 150 pounder you need springs.

Guideon72
03-29-2005, 11:36 PM
But how do I determine what these things are set at, and how can I adjust them (outside of installing the new springs)?

Gas Man
03-29-2005, 11:52 PM
Check you manual... it will help you out and will give you pics...

Guideon72
03-30-2005, 12:14 AM
I really hate overlooking the obvious :bash: Thanks Gas and everyone else! I'll get this thing setup eventually :cheers: :bluemc: -G

No Worries
03-30-2005, 12:27 AM
Changing the fork oil weight will change the damping. But your problem appears to be the springs. You need two helpers to measure sag, which should be 1 inch. The helpers lift the front end until wheel is almost off ground. Other measures from top of fork tube to fixed point (say it's 7 inches). Then with rider on bike, one holding bike from tipping, and other measuring from top of fork to same fixed point (say it's 5 inches). The sag is therefore 2 inches. If your fork has a preload-adjuster bolt on the top, crank in preload and measure again. If your fork isn't adjustable for preload, you will have to make longer spacers out of PVC pipe to put on the fork spring, or even better, get heavier fork springs.

SpeedWerks.com
03-30-2005, 01:10 AM
On the SV, one of the "cheap" items for cost-savings is the forks ... they're a damping-rod fork with way too little damping stock for any sort of sport or track riding. We would suggest a .95 spring rate for your weight, and 20w for street or 30w for track in regard to fork-oil. A set of RaceTech emulators will also really help as you can adjust the damping rates to your liking. A GSXR front end is also an option, as Twisty mentioned, but it's heavy compared to the stock SV forks and if you're thinking about racing it takes you out of the SS classes. It does offer you a set of real catridge forks though, which offers a lot of adjustability, so the trade-off for weight might be worth it to you. - Brian Roach - SpeedWerks.com

twisty
03-30-2005, 06:11 AM
A GSXR front end is also an option, as Twisty mentioned, but it's heavy compared to the stock SV forks and if you're thinking about racing it takes you out of the SS classes. It does offer you a set of real catridge forks though, which offers a lot of adjustability, so the trade-off for weight might be worth it to you. - Brian Roach - SpeedWerks.com I didnt think he was gonna race it, but your right.

Guideon72
03-30-2005, 02:22 PM
Heh, you were right Twisty ;) Not planning on racing at this point...I just want the front end to not bottom out when I hit the brakes at 30mph :tt: Thanks everyone for the input. I got my Sportbike 101 book from Speedwerks :thumbs: last night and found the adjustments and all that I need. I'm planning on looking into the springs and oil once I get my return. Brian: Yeah, the .95k/20w combo is what I managed to find in several places also. Can I mail you directly with some more questions on this stuff? Thanks guys!!! :twfrox: :twfrox: :bluemc: -G