Hey CBR enthousiasts,

Last week i've put an F4i shock on my F2. Now it is a huge improvement and after fiddling with preload adjustment the ride is much better, but i'm confused.

My shock has no, and I do mean 0, adjustment options besides preload. It looks and feels identical to the OEM F4i shock, but without the adjustment options. Is this not F4i, is this a different model year? If anyone would know, greatly appreciated.

Picture to clarify:

Dont mind this solid mounting solution, making a bracket for that.
F4i:


Its obviously different, yet it looks exactly the same and has the same dimensions.

 

pictures are great but is that not a gas chamber with compression adjustment on it ?.
How does it ride, I have been thinking about putting an F4 shock on mine but worried about adjusting the ride height.

 

from what i heard and read it raises it about an inch and 3/4, some have said it will cause problems, or have said it will be okay. Imma just add a lowering link to put the ride height back down to its original height.

 

I read somewhere on this site a lowering link wont work. Something is in the way. If I remember correctly. You probably could use a 70 series front tire and/or lower the forks in the clamps a little to get some of the levelness back in the bike. You would basicly be raising the front to get it closer to the amount the F4 shock would be raising the rear.

 

Really interesting, well dammit that is good to know. well i guess the only other option is to lower the front end. will just effect turn in...

 

Most f2 and f3 track riders with a Fox shock usually raise the rear a little anyway, but no where near the 1.75 inches the F4 shock raises it. Helps with turn in and quicker steering. But if you go to much you sacrifice straight line stability and rear end traction. So by dropping the forks in the clamps (less fork sticking up through the clamps) you will get some of the levelness back into the bike from where the F4 shock raises it. So your not lowering the front end like you said above, you are raising the front end. And of course the use of a 70 series front tire instead of the stock sized 60 series helps get some of the levelness back into the bike.

 

The answer is Yes, there are two types. One with adjustment on rebound (easily seen on the reservoir) and one without.

I've got the 120/70 up front indeed and top clamp is as far up as it will reasonably go. Side stand lengthened by about a centimeter to keep it from parking poorly. And i've got the wider 5inch rim with the 160/60 tire, effectively another little bit lower. These mods are easy to do and do get it where it needs to be. Needed a new tire front and rear anyway, so i looked for a proper rear wheel together.

These things combined it is in no way unstable on the throttle. No matter speed or agression on the the throttle the bike is much more planted then with stock (and bad) rear shock. Remember the poor condition some F2 shocks are in, any upgrade will help greatly. The difference in turn in is obvious, but if your not a new rider it actually makes steering easier without becoming overly nervous. I personally feel the original geometry of the F2 was rather lazy anyway, so jea, i'm happy.

Yesterday i swapped the shock for one with preload compression. The simple one i removed and I wil mount that to a friends F2 which currently also has a terrible shock mounted. I personally do feel that with the lighter steering it requires a more gentle style of riding in normal road conditions. But my expectations is that that will make it much less of a hassle to push it into corners on the track.

Will give it some serious testing after I swap the rear rim, I had to get the F3 spacers which i forgot.