gsxr600 fork compression

[BoltonSte]

Does anyone know what the minimum length '01 GSXR forks compress to?

They are the right way up (not sure when there was a change)

And do any of our resident suspension experts know which other forks can be used in the GSXR yokes?

Cheers

Ste

[21QUEST]

Forks on bike?

Anyhoos, just undo fork cap, compress and make note of it. If on the bike you got to be a bit careful of course, when lowering the bike down to check.

Re what other forks, if not bothered about if calipers line up with what ever wheels you'll be using, early Freblade springs to mind and also CBR600(rr1-rr3 for sure)


Ben

[BoltonSte]

I was trying to figure out which causes the bottoming out, if it's the spring being fully compressed, hydraulic lock from the oil, or the the fork tubes hitting the stops:confused:

I was hoping to be able to figure it without having to mess with the forks.

Ahh wel I'll have to have a play, at least they're off the bike.

Cheers

Ste

[yorkie_chris]

Doesn't really matter what stops the forks moving so long as its not the wheel embedding itself in your rad :-P

The caps off way is pretty fool proof to check where they're going to end up at full compression.


The k4 600 was when they got upside down forks.

[Red Herring]

I'm, afraid I wasn't as scientific as that. After doing my GSXR K4 conversion I wound all the preload out of the forks and put a cable tie around one of the stancions. I then went out and did a couple of stoppies outside the house. The cable tie was pushed right down to within a couple of mm of the bottom of the stantion, so I figured that was pretty close to bottoming out. I then wound in enough preload so that when I repeated the exercise I was left with about 10mm between the cable tie and the bottom of the stantion. I wanted to get away without fitting stiffer springs and so far I seemed to have managed it.

[BoltonSte]

I've had a look at it, there is 4.9" of travel, the problem is I only have 3.9-4.5" clearance before the wheel hits the rad (this is an extremely non-standard bike) I was initially told that there would be sufficient clearance by the garage, however, when I fit a fan to the radiator I have this problem (hence my other post wondering what the thinnest fan out there is).

I've hunted round the web and have found that a lot of Drag racers add spacers above the topping out springs which pulls the damping rod and lower tube up, this reduces travel but also fork length (which I don't want)

Do the masses know of any way to reduce fork stroke while keeping the fork the same length?

I was thinking (depending on what actually bottoms out first) that if I get the same rate spring but shorter (or cut the existing spring) and then take up the gap with a longer preload spacer that this will effectively reduce the distance the fork compresses before the spring bottoms out.

Other methods are something like this: http://www.traxxion.com/store/detail.asp?product_id=ESFC which I may be able to get made at work,

Or a completely new front end (of anyone knows of any that will fit and have a greater offset than the gixxer so the forks are further forward from the rad.

Apologies for the post length, but I want to check what my options are (measure twice cut once)

Cheers

ste

[21QUEST]

GIXER offset is probably the largest of all the yokes I can think off...maybe some Hondas but you then have decreasing trail with an already short fork.

I'm not sure if Racetech do fork extenders for he RWU Gixers...usually gives you an extra 10mm.

Another option is to get a stepped yoke/dropped yoke(?)...whch is what I have on my SV. You then might or might not need to raise the back a bit...using a dogbones or via a shock with a ride height adjuster.


Ben

[BoltonSte]

Ben, is your yoke OEM from another bike? If so whats it off, sounds like this maybe a better option.

If not do you have any other info on how it was done?

Cheers

Ste

[21QUEST]

Ste, yoke is bespoke. I had it made as I'm one of those that like quite a lazy geometry...I call it neutral handling lol

There are a few yokes out there, come to think of it that are stepped as standard. Off hand, I think the early Honda fireblade with 45mm forks(don't know howmuch mind). The first R1 wih Radials also is stepped but of course the fork holes are larger but you can always have sleeves made.

So we don't go round in circles, how much more height do you reckon you need. Give me something solid to check for.....and I'll do a few checks for you.

With using RWU forks, it's not so bad to line everything up as you just need to space calipers in if you get a yoke that is slightly wider(centre to centre distance). only other thing is stem but first thing is to have how much more length you need.


Ben

[21QUEST]

Righto, just read your other post again...looks like you need about an inch to play with. I'll do some checks for you.


Ben

[Blue_SV650S]

I was thinking (depending on what actually bottoms out first) that if I get the same rate spring but shorter (or cut the existing spring) and then take up the gap with a longer preload spacer that this will effectively reduce the distance the fork compresses before the spring bottoms out.

:smt103 That is a SERIOUSLY bad idea!! :shock:

Although the forks getting prematurely 'coil bound' might save your rad from the front wheel, it will have you 'down the road' in no time!! :shock:

I see your only solution is to fit some higher rate springs. Seens as you want to keep travel to a minimum, but will probably want the front end to track the road a bit ;) Some progressive ones would make most sense.

[Red Herring]

What do you use the bike for. Do you need a cooling fan? Seems to me the easiest soloution is to move the rad back out of the way, and if you can do so by removing the fan that might be best.

[BoltonSte]

It's eventually going to be a road bike so I would like to keep the option of having a fan if possible, because at some point I will get stuck in traffic.