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Forks will need work


Cruizin

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I'm one of those who always matches my front springs to my weight/revalve any bike I own. Many do this..
 
On the FZ-09, you cant even set proper sag because the front is so soft you run out of adjustment room. On the FJ-09 it will be the same, so I will probably have a whole new internal installed an even afterwards, it will still a heck of a bargain for this bike.
 
The stock FZ-09 does 0-60 in 2.7 and 1/4 mile in mid ten seconds. This bike is only what, 45 lbs heavier than an FZ-09?
 
It will kill the twisties with a little fork work done and I don't really mind doing it a bit.
 
If it had better forks it wouldn't be a $10,500 bike and I can do it cheaper than the factory.
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  • 4 months later...
I did my first test ride Saturday. First things I noticed were Throttle by wire roll ons, rough suspension, lack of absorption, for the amount of travel the FJ09 has and a handle bar buzzing at legal, in CA, cruising speeds of 62-70 MPH. I had Traxxion do my last fork set up, 10 years ago, and a Penske for the rear. But I thought a std set up with this much travel on the FJ would absorb much better then it did. I'm 194 lbs and stock set up should have been adequate (IMO).
Everyday's a good day when your able to ride
 
15 FJ-09 - 2WDW ECU flash, Givi SV201, Nelson Rigg tail bag, OES sliders, Koubalink extenders, Ermax Sport, Vista Cruise, OEM seat mod, (smiles)
07 Honda ST1300A (sold)
06 Kawi KLR650 - Big Gun full exhaust, Corbin, Givi, PMR racks, carb mod (keeper)
97 Honda VFR750 - Traxxion Dynamics, Penske, Givi 3 piece, carbon exhaust (keeper?)
20+ years of snowmobiles
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  • 4 months later...
I've got about 300 miles on my FJ and am starting to push it a bit. I am becoming increasingly unhappy with the stock suspension. The forks dive too much and the dampening of both the forks and the shock is clearly deficient and the weakest point of the bike. I will certainly do suspension upgrades but I am trying to decide if the andreanni/ base ohlins package will be good enough or whether I should lay down the extra dough for something more. I do plan to call around to some of the suspension shops in town (Portland, OR) to see what they may recommend.  Does anyone have any shop recommendations? 
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There might be a Racetech Service center.... Yup. http://www.racetech.com/page/id/72
 
ADDRESS : CARDENAS MOTORSPORTS
19475 S W 89TH AVE
TUALATIN OR 97062
WEBSITE : CARDENASMOTORSPORTS.COM
PHONE : 503-351-7818
 
EMAIL: MIKESRACING03@GMAIL.COM
 
 
I think spending about $750 for a better than 'basic' Ohlins shock is worth it (see a budding list of options here: http://fj-09.org/post/21517). However, talk to Fast-Bike Industries and see if he can pass on the special Andreani+Ohlins deal for ~$850 like you can get from Italy. I haven't set eyes on this particular incarnation of the Andreani kit (I reviewed the one for the FZ07 after which the factory appears to have fixed one of the points raised) and it needed some notable, but not complicated fixes out of the box. The combo price is a very good deal IMO even factoring paying someone (eg. yours truly) an extra $100 to fix it. A common price to install said kit is $125 to as much as $200.
 
For forks, the Traxxion AK-20 is IMO the undisputed king of the hill. Next up would be Matris. Then there's guys like me whose stock in trade is getting most of the way there, for much less.
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  • 5 months later...
At least the suspension isn't quite a dire as the FZ09...
 
So here's some fork damping curves. Since all damping is done by just one leg, I doubled up the GSXR and Forks-by-Matt curves.
 
The thin+thick line pairs show the base valve's contribution to compression damping and then when you add the restrictive orifice mid-valve. The FJ09 base valve isn't that bad if they had simply changed out the mid-valve piston for any of the non-restrictive models in the KYB catalog.
 
fz09%20vs%20fj09%20-%20force.gif
 
The ~50in/sec range is what people attribute to "feel" or "stability under braking". There's a sharp point in the Forks-by-Matt curve (RaceTech's likewise) because my shim stack is preloaded.
 
I drew the orange dashed line to show that Yamaha added ~25% more damping to the base valve between the FZ and FJ
 
For reference, a 1" bump hit at 70mph is 250in/sec of shaft rate.
street-17f.png
 
Below we see the difference the needle can make between wide open (U.wo) and fully closed (U.clsd) for rebound. Someone on the FZ09 board posted that his tuner had remarked there was f-all adjustment on the FZ09's rebound needle. And indeed we can see that is definitely the case.
 
fz09%20vs%20fj09%20-%20rebound%20force.gif
 
Unlike the Comp graph, the FbM and GSXR lines aren't doubled. I ran the "single-leg doing all rebound" simulation using FbM as the "perfect" curve and that's represented as 'Double Spring'.
 
We see that the FZ09 when fully closed barely handles what the GSXR does at typical openings (not graphed), despite needing to handle twice as much spring. Colossal screw up by Yamaha/KYB.
 
Conversely the FJ09 brackets the 'Double' so needle adjustments will achieve the desired behavior. I graphed the Andreani kit's range just for fun.
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  • Premium Member
Thanks for posting the technical data that supports the dramatically improved feel of your upgrade to my forks. The difference is fantastic. Almost no brake dive, unless I'm really on the binders. No more sharpness to high speed bumps. Excellent work, highly recommend.
Can't wait to get your JRi-double installed to balance the back end with the front!
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