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Main Area => General GS500 Discussion => Topic started by: Bluehaze on May 15, 2009, 03:09:23 PM

Title: suspension tuning
Post by: Bluehaze on May 15, 2009, 03:09:23 PM
So i am taking this bike to the track on June 3rd at the Pacific Raceway.

I changed my front stock spring to .90 raceteck springs. I did NOT change the oil. I just changed the spring. While i dont bottom out anymore, i still feel myself jerking forward fast when i brake hard on the front brake. 

Question 1:  On a 2008 GS500F, what is the stock front fork oil in there?  I spoke to dealership and they said most put 5W.. seeing that i didnt know then.. i bought 10w and 15w.  I am tempted to put 15w on there.  I weight 175 and with gear i think it puts me to 185-195.   15w will definitely take away that jerking foward..but it also means slower on rebound as well.

If, its a 5w right now.. i might just move to 10w and see how that goes.

Title: Re: suspension tuning
Post by: ineedanap on May 15, 2009, 05:15:34 PM
I'm no suspension expert and I'm sure someone will chime in soon, but...here's my 2 cents.

Stock isn't 5, it's 10.  5 is for all the fancy new sportbikes with cartridge forks and upside down suspensions.  We're stuck with damper rod junk and have to run thicker oil.  I believe most people run 15 as a starting point.  I wouldn't worry about the thicker oil slowing down the rebound too much.  It's way too fast anyway, even with thicker oil.  (at least I think so)

Have fun at Pacific Raceway.  Make sure you post some photos!!!!!
Title: Re: suspension tuning
Post by: ATLRIDER on May 15, 2009, 06:39:46 PM
I also think 10w is stock.  15w is probably just the starting point for the track.  I have progressives and 15w and could have gone with a heavier oil.
Title: Re: suspension tuning
Post by: jeremy_nash on May 15, 2009, 06:59:45 PM
yes, factory weight is 10, I had the dealership look it up for me awhile back
Title: Re: suspension tuning
Post by: Bluehaze on May 15, 2009, 08:43:17 PM
 :mad: so i tried to remove the rear suspension. Since buddha sent me a gsxr rear suspension.  For the bottom bolt of the rear suspension.  Well unfortunately i managed to strip the bolt.  I used 14mm as the 13 would not fit.  But the damn thing will not turn.. so my brother said.. well as long as you are using the right bolt its just got loctite and you need to just keep putting pressure.. well unfortuantely that stripped it. so now its almost rounded.. so then i thought to use  vicegrip.. but for the life of me it will not turn.. even the vicegrip i can see it just stripping the stupid bolt some more.  wtf.. what do i need to do here?/????   do you need pictures?
Title: Re: suspension tuning
Post by: ATLRIDER on May 15, 2009, 09:09:02 PM
Are you trying to turn it from the nut side or the bolt head?   Should be from the nut side.
Title: Re: suspension tuning
Post by: jeremy_nash on May 15, 2009, 09:25:39 PM
exactly, if you have stripped it, vice grips and some good penetrating oil are your best friends. if the vice grips wont grip it, you could use a pipe wrench, cause the more force you put against them, the tighter they grip
Title: Re: suspension tuning
Post by: Bluehaze on May 15, 2009, 10:14:18 PM
this is from the nut side.  not the bolt. 
Title: Re: suspension tuning
Post by: Bluesmudge on May 16, 2009, 12:18:54 AM
I'm running .90 sonics. You need to replace the oil, it makes more of a difference than the springs do. I'm running 15w but would consider going to 20. Or maybe 20 in one fork and 15 in the other. I haven't tried heavier oil though so I can't say what's better. BUT, do change the oil. I don't know how many miles you have on your bike, but for me switching to some fresh 15w made all the difference. Goes well with the kat shock now, didn't really before the oil change. I'm weigh a similar about at ~190 +/- with gear.
Title: Re: suspension tuning
Post by: Big Shot on May 16, 2009, 01:47:39 AM
Quote from: Bluesmudge on May 16, 2009, 12:18:54 AM
I'm running .90 sonics. You need to replace the oil, it makes more of a difference than the springs do. I'm running 15w but would consider going to 20. Or maybe 20 in one fork and 15 in the other. I haven't tried heavier oil though so I can't say what's better. BUT, do change the oil. I don't know how many miles you have on your bike, but for me switching to some fresh 15w made all the difference. Goes well with the kat shock now, didn't really before the oil change. I'm weigh a similar about at ~190 +/- with gear.

Maybe i'm reading this wrong, but you do not want to go 20w in one fork leg and then 15w in the other.  They would respond differently...


? - Bob!
Title: Re: suspension tuning
Post by: Chanse on May 16, 2009, 02:06:47 AM
Im running stock spring and 30w.  of course Im 240lbs. Anyways on the bolt. Yeah and dont put two different weight oils in opposing forks. One side will be quicker to respond and give a kick to one side... What we used to on rims with locking lugs and no key and stripped bolts is get some impact sockets, find the one that slips on but tight. go down a size line up the flat sides and pound it on witha hammer  :technical:. Then pull it off, use the hammer again and go down a size, and you guessed it.  :technical:. Then once that ones on hit it with the impact a few quick rounds and it should come right off, If not go down another size and repeat until it comes. Always worked for me.....
Title: Re: suspension tuning
Post by: fred on May 16, 2009, 03:09:11 AM
Quote from: Bluehaze on May 15, 2009, 10:14:18 PM
this is from the nut side.  not the bolt. 

Use lots of penetrating oil. Then have someone hold the bike while you pound the next smallest sized socket over the stripped nut with a hammer. If you're lucky, you'll force the nut into a new shape that the socket can now turn. Get a new nut from the dealer and you're back on the road. The pounding will probably also help loosen all the corrosion and loctite that's keeping it from turning, so it should be a pretty easy proceedure.
Title: Re: suspension tuning
Post by: Bluehaze on May 16, 2009, 10:01:30 AM
thanks for the responses guys. i think i am good to go.. got hold of suzuki stevo and he will do his majic on it.   guess i will ask him the trick to getting in off in the future.. i thought it was just a normal nut to unloosen.. or i might have just been unlucky.
Title: Re: suspension tuning
Post by: Bluesmudge on May 16, 2009, 12:08:11 PM
I don't think you were unlucky. When I put in my Kat shock I couldn't get thing to budge and I could tell I was going to strip something so I had to used an impact wrench on it
Title: Re: suspension tuning
Post by: fred on May 16, 2009, 07:39:52 PM
Quote from: Bluesmudge on May 16, 2009, 12:08:11 PM
I don't think you were unlucky. When I put in my Kat shock I couldn't get thing to budge and I could tell I was going to strip something so I had to used an impact wrench on it

Yeah, given the number of screws and nuts that have tried to strip or round on me when I try to remove them, I think I'm going to have to start looking for a decent impact driver and impact wrench. I swear, these bolts and screws are made of the softest metal known to man. You could probably make them out of lead and do better...
Title: Re: suspension tuning
Post by: Suzuki Stevo on May 16, 2009, 08:13:14 PM
The nut was soft enough that when you cinched down on it with Vice-Grips it would deform and the threads would seize together, I was victorious though...

(http://home.comcast.net/~stykers/victory.jpg)   
Title: Re: suspension tuning
Post by: Bluehaze on May 16, 2009, 08:25:15 PM
yep i was taken care of. thanks again stevo. awesome awesome job.  cold corona and good conversation made that afternoon very very good.