how hard do you ride? and weight? i recently bought some racetech .90 springs and will be doing my swap soon. i was considering using 15wt oil, but after what vangill said, would like to hear some opinions on it.

 

dont take my opinions as fact! lol you can, im never wrong-at least i hope
but seriously-about the fork oil, if you have a trusty shop ask them about if the heavier weight is an issue. it may not be and i (and what my shop said) could be full of it. i just know how hard i ride and i didnt want to risk it. i wish my bike was bulletproof! but the forks do feel great after just new oil.
but if i was gona do even 250$on springs and stuff-id redo the front end completely-i dont think id notice enough difference with just springs and i know too many guys with nice front ends i could get for that much.

to be honest-i think a lot of stuff could be in our heads when it comes to improvement

 

i weigh 175 without gear. i cut my spacers to 75mm with the racetech .90 springs, and set my preload (rider sag) to 33mm with 4 lines showing.

i live in north georgia and ride the GA, NC, TN and VA mountain twisties at a spirited pace at least once a month during the riding season. i haven't done a track day on the F4i, although i used to track my old R6.

like vangill said, if you got money to burn then revalve it. i upgraded my springs last winter, and i rode with maxima 15wt oil all season without a single issue. i was able to dial in my rebound/compression exactly where i wanted it. keep in mind that with a stiffer spring, you ARE going to need better damping whether it's gold valves or just thicker fork oil. it all depends on the size of your wallet. but my wallet ain't nearly as big as it was 5 years ago, when i wouldn't have thought twice about buying gold valves.

 

thanks both vangill and stingray for the opinions. vangill, new springs are only $100 granted you can to the labor yourself. most say that just new springs are worth it depending on your weight.

i will probably give racetech a call before i start the swap and see what their opinion is for fork oil weight.

 

racetech suggests a 5wt oil. hmmm. i think ill give ohlins a call and see if they second that.

 

thats what the shops told me to put in too, but then they looked it up and it said 10, i rode on it today and with 10 wt its much stiffer than my buddies r6, but it feels good.

 

if you swap oem with right springs you will need revalving cause stock spring is 0,66 but for track you will use 0,9-1,0 depends on your weight. there is too much difference and stock rebound shim stack can't manage so heavy spring. I have 0,95 spring and only 20wt oil helped but this is too thick oil for compression side. actually you can DIY re-valve and there was how to thread. only remember that rebound valve end nut is peened. then buy shims (OD17xID6x0,1) and add some go to track, disassemble again, add/remove shims, go to track and so on. then do the same with compression shims