Forks modification advice

[tommyardin]

Thanks for that, im working my way through your post Kebab19's and all the replies even if admittedly some of it is a bit beyond me. Should be able to drill some holes though... I think I better grab those forks then and start getting into it, even though I don't have much experience on bikes other than the fazer and my dad's vmax 1700 trike I can still feel that the fazers handling is a bit boat like at times.

[size=1em]I have no doubt that anyone with a modicum of common sense and a little bit of skill spanner spinning and nifty with a power drill, can do this well worth while modification.[/size]

[size=1em]Don't rush it, take your time, think it through and work precisely and cleanly. [/size]

[size=1em]I did mine with a lot of help from Kebab19's post's and having dialog with him via messaging.[/size]

[size=1em]Keep the drilling as low as possible on the damper rods, early FZS 600 Dampers are 210mm long, the later model's Dampers are 190mm long, if you measure about 5 or 6mm from above the top of the axle hole in the bottom fork legs (Sliders) by 210mm or 190mm depending on the year of your Fazer FZS 600 you can tell where the top of the damper rods will be inside the damaged forks, before taking them apart[/size]

[size=1em]My FZS is a 2003, so I had the shorter 190 mm damper rods, it is paramount that you keep the holes that you drill to overcome the damping effects of the damper rods as low as you possibly can, if these holes encroach into the upper chambers of the forks on full compression your damping will be compromised at the very least. [/size]

[size=1em]A lot of the manufacturers of the emulators advise 3 X 8 mm holes, that in itself is a little confusing as it means 3 X pairs of 8mm holes (You are drilling through the two walls of a tube) with at least 10 mm of complete damper rod between each of the 3 sets of holes.[/size]

[size=1em]So starting at the original oil release hole (5 mm) in the damper rod, drill this out to 8 mm then drill another 8 mm hole at 90 degrees around the damper road leaving at least 10 mm of damper rod between these sets of holes, then repeat again for the 3rd set of 8 mm holes and you should be back directly above/inline with the first set you drilled.[/size]
[size=1em]Now if you add the 3 X 8 mm holes together (3 X 8 = 24) then the two times 10 mm distances between the sets of holes (2 X 10 = 20) add the two measurement together 24 + 20 = 44 that is how far you have come up the damper rods, I personally felt that it was getting very close to the point of encroachment into the upper chambers of the rods, especially with the shorter 190 mm damper rods.[/size]

[size=1em]Now 2 X 10 mm holes have pretty much the same area size as 3 X 8mm holes. [/size]
[size=1em](Google it there are charts that will show you how to work out the area of a circle or round hole)[/size]

[size=1em]I lowered the original 5 mm damper holes by 3 mm by measuring accurately and marking with a permanent sharpie pen, then with a fine chain saw sharpening file I lowered the hole in both damper rods by that amount (3 mm) so I have now lowered my datum/starting point by 3 mm. I then drilled my first 10 mm holes at the lowest point of my datum hole, I then allowed 15 mm between the first and second set of holes again 90 degrees around the damper, I drilled the second set of 10 mm holes. [/size]

[size=1em]Now as stated earlier, my two pairs of 10 mm holes have the same value as 3 pairs of 8 mm holes.[/size]

[size=1em]2 X 10 mm holes = 20 mm. 1 X 15 mm space between the two sets of holes = 15 mm.[/size]
[size=1em]20 mm + 15 mm = 35 mm, Now minus the 3 mm that I lowered the original damper hole by filing it lower = 32 mm, as you can see I have lowered the drilling to the damper rods by the difference between 44 mm and 32, i have lowered the drilling by 12mm. [/size]

[size=1em]Plus I have 15 mm between the holes which must have less structural weakening impact on the damper rods, and the are only two pairs of hole as opposed to 3 pairs.[/size]

[size=1em]Sorry if this has been written in a laborious way but I felt it was worth and important to spell it out clearly, as you know the forks are a really important part of the motorcycles structure.[/size]
[size=1em]Anyone doing either of the two ways mentioned above does entirely at their own risk, none of what is written is a recommendation to anyone, but just my thoughts and practice when I did my forks. [/size]

[size=1em]I am not an expert or an engineer, in fact I was a brickie before retiring, but I am a very practical person that likes to think things through and work precisely.[/size]
[size=1em]My old dad drummed it into me and you all know the old adage 'A Job worth doing is worth .........................'    [/size]

[size=1em]Please note that when talking about the land between the pairs of damper rod holes that you drill it means Between the top of one pair of holes to the bottom of the next pair, it does not mean a centre of hole measurement.  [/size]