Alright, I'm new to the board and have done some searching on the topic of inverted forks on a F4i. I own a 2003 F4i, with what I believe to be the '07-'08 RR front forks on it (might be '05-'06s though). I did not do this conversion, nor do I want to undo it. I rode the bike last season the way it is now, not even changing the suspension settings. Now that I have a season under my belt, I'm fixing the fairings and trying to fix as much else as possible.

Currently my handlebars are too low for my comfort as they are mounted under the top tree. I would like to move the shocks down in the clamps and allow myself to reposition the bars above the tree. However, if it is going to greatly upset my handling to do so I am not willing to do it.

Here's the question, what is the height from the ground to the bottom of the oil filter housing, with both front and rear suspension preload set to full hard? I figure if I can get this measurement, it will at least somewhat keep the F/R balance correct. I don't know the difference in spring rates between the two, so if anyone knows them post them up please.

Again, I know this suspension setup will not handle like factory, but I'm trying to make it as right as possible. Any help or suggestions are greatly appreciated.

Thanks in advance,
Kevin

 

I would think the superior design of the forks on your bike now would be better than what was on there stock. I put a 954 front on mine although I haven't finished it enough to ride it yet. Do you like the way the bike handles now? There are a number of companies that sell bars with greater rise built into them.

 

I have never ridden a bike other than this one, not on the road at least. The goal of this isn't so much to raise the handlebars rather to make sure my F/R balance is roughly factory. I don't trust the previous owner's thinking ability enough to accept that this balance was taken into account.

 

I like you already. unfortunately, I no longer have my F4i so I cant provide the exact measurment for you. Although, I think you are on the right track.

keep in mind, depending on what forks you have, some of them have a top out springs in them. so no matter how much you crank the preload, it wont change the height.

If you can get an accurate measurement, and slide the fork tubes in the clamps to match that you will be good.

 

Well, I don't know if this will help. These are specs from the Service manual (2001-03):

Overall height .................... 1.135 mm (44.7 in)
Seat height ....................... 810 mm (31.9 in)
Footpeg height .................. 360 mm (14.2 in)
Ground clearance ............... 135 mm (5.3 in)

 

Nah, those don't really help. I need a fixed point measurement close to the front, preferably ground to oil filter housing. Anybody?

 

Anybody out there that has the ability to get this measurement for me?

 

With what you're doing it will cause a geometry change. Those measurement are called Rake and Trail and can be found most anywhere including your owners manual (sorry I don't have mine handy).

I'd recommend setting sag first then readjust geometry. Since you like what you have now, use that as a baseline. But when you move your forks enough to put the handlebars on top of the tree it's going to be a RADICAL geometry change.

What to expect with your proposed changes:
Majorly quick Turn-in Speed
Major instability
Major weight shift f/r while braking/accelerating
Major back/neck pain, possibly shoulder/wrist pains
Increased front tire wear

What you need are a set of fork extenders. I don't know if anyone made something for that bike (RR). I'd recommend that you take your bike to a suspension shop that knows what they're doing, cause you're going to need expert advice/help with your setup. Best to you.

Sorry to be the bearer of bad news. But I hope that the truth serves you best.

 

https://cbrforum.com/forum/f4i-main-forum-11/my-f4i-project-87183/

I put gsxr 750 forks on mine, they are about an inch shorter than f4i forks which are prolly the closest your gonna find. I run clip ons on top the triple (its underneath in the pics but I've moved them) and still plenty clearance between tire and rad. Rides perfect. Used 929 triples. Feels like stock riding position.

1000rr and 600rr forks are a couple inches shorter than f4i, even with clipons under the triples the tire is close to the rad and your really stretched out since clipons are low as your finding out. Thats why I didn't go with 600rr forks. I would of went with 929/954 forks but finding a 929/954 front rim is next to impossible without spending a ton.

With a ho hey upper triple you can run your clip on's on top and pull the forks down some in the triples so your not so stretched out.