Guys, I need some help here. I am putting a set of F3 cartridges into a different set of forks on a different vintage bike, to cure a persistent chatter problem. I am ready to put them together, and send them off to race on in a few weeks. But I race sort of out of a suitcase, and won't see the bike until I get to the racetrack, so I need some setup help for a reasonable starting place. What I am trying to figure out is oil weight and height, and rebound clicker settings, for a starting point. Can any of you share that info with me? I have looked around the internet and found 120mm oil height, on 20 weight oil, with the rebound clickers set 2 from all the way in (I think this came from an old Sport Rider magazine article). Does that bear any resemblance to what people actually use on their F3's? I would appreciate any help. I am guessing these settings are street settings, and the high oil height is compensating for the soft stock springs, but the oil weight and rebound settings are in the ballpark. What do all you guys that race these things say? Thanks a lot in advance.
Sounds about right on the settings as far as the rebound. The other stuff the guy doing the forks will do.
I use what Race Tech recommended on their website after plugging in rider and bike weight and what it would be used for (racing). I thought for height I ended up with 130mm and 10 weight oil, but I would have to check my notes to be sure.
You should have 120mm of air space between the oil and the top of the fork, not necessarily 120mm of actual oil. I run 10wt, personally I find 20 to be a little too sluggish but its really preference.
Yeah, this is starting to sound like normal numbers I would expect. Without knowing, I would use 130-135 mm oil height and 10 wt for "normal" cartridges, with "normal" race weight springs. RaceTech says, 135mm, 10 wt, with their cartridges and springs, so there you are. The stock springs are only about 42 lb, and so I guess to compensate without changing springs, the internet says set the oil height high (120 mm) , and the oil weight is high (like 15-20 wt). Another question for guys racing F3's is, stock do they have adequate rebound damping? That could be another reason for the 15-20 wt oil, and setting the rebound just 2 out. I appreciate your help. Just trying to get ahead of the power curve here, I'll be busy with 2 bikes. Thanks!
Did you get the chatter figured out? I am running F3 forks on a 600 Hurricane and have terrible corner exit chatter/front wheel hop. I'm willing to tear into the forks, but it would be nice to find a starting point for resolution.
Well, I'm not your guy because I put these cartridges in fzr600 forks on my 255 lb RD 400 AHRMA F500 bike, and I have no info on fixing an actual F3. Sorry I can't help except to say I always have encountered chatter on the way in, on neutral or trailing throttle, when the forks are compressed, and it would go away as you pick up the throttle. About all I can suggest is see the local suspension guy you trust. As to how they worked on my bike at Miller, great, started with 10 wt and clickers in the middle and I am working my way to more rebound as I go. 40 lb (.7) springs for such a light bike (I'm not little, I think I weigh almost as much as the bike in my gear). However, I changed to Dunlop kr145 and 145a tires, which are tons better than the 124/164's (these feel more like the modern slicks on my R-1 than like vintage race tires, very stable when loaded up from middle out and lots of front bite and trail braking traction too), and I started with the last settings on the forks with the Emulators in them, before I switched to the pair with the F3 cartridges. Guess what? The chatter was cut by at least half by the tires, about as good as I got the cartridges first weekend--so I now have two pair of forks that work about equally well. verdict: new Dunlops perfect, new F3 cartridges really, really good, on their way.
