Honda F4i
Updates: 1/19/09
Sorry for the lack of updates in quite a while. Long story short, I upgraded my version of MS FrontPage from when I originally created this page and it hosed my original files. I've been trying to slowly salvage the original links and content, but I finally decided to just say screw it and just start putting more info on here. I've done and learned a lot about the bike, suspension, tire wear, brakes, you name it. Keep checking back as I add things... (scroll down to updates section in links)
Brembo Master Cylinder (in progress)
Galfer Wave Rotors
Vesrah RJL brake pads
Cheetah Track Day Upper Fairing
2CT tire wear & air pressures (in progress)
Track Days (in progress)
Baxley Sport Chock
Laptimer for track days
Track day pictures
Traxxion Dynamics Fork Springs
Yet another great mod that really made a difference in the handling of the bike. The stock fork springs are way too soft for even me at 145 lbs without gear. During my first trackday at Barber in Alabama, I was bottoming the front forks during heavy braking. The front tire was actually chirping as my speeds increased throughout the day. Nothing like a little pucker factor on the track to encourage spending some money and correcting issues with the handling of the bike.
I upgraded the springs with a 0.90 & .95 spring for an average spring rate of 0.925 as recommended by Traxxion.
They sent me everything I needed to swap the springs: new springs, correct spacers, fork fluid gage & fluid height.
Basic wrenches and a vise with padded jaws were all that was needed. Overall a very easy mod, and I've never worked on any motorcycle forks before. I did everything in about 2 hours which included: removing the upper cowl & fairing, front wheel and calipers, clipons, & removing the forks from the triple clamps.
Since the forks were off the bike and apart for the spring install, I drained the stock fork fluid and replaced it with Maxima 125-150 Racing Formula fork fluid (7WT. SUS-VI). The front end feels far more planted now and good sag numbers for street or track are easy to attain.
I plan to upgrade the valving or go with the complete cartridges offered by Traxxion Dynamics sometime in 06. I will most likely go with the cartridge upgrade since they can be fitted to any bike, so my investment will continue to be useful even after swapping bikes in 2-3 years.
Traxxion Dynamics AK20 Cartridges:
http://www.traxxion.com/store/product_pages/products.fork.asp
The cartridges in the forks just weren't giving me the kind of adjustments that I needed for a lot of track day duty, nor were they working very well on the street. I sent the forks to Traxxion and had them back in a week. The difference is night and day, I can now turn make compression & rebound adjustments in slight increments and see / feel the impact to both handling and tire wear. If you are going to be doing track days, I highly recommend getting the valving & springs reworked in your forks. The effects are really nice on the street as well, the bike rides better and soaks up bumps in the pavement giving you a lot more confidence that the bike will hold a line and traction.
Penske Triple clicker rear shock
http://www.traxxion.com/store/product_pages/products.shock.asp
This was a night and day difference mod to the F4i as well. My stock shock had significant internal issues with the adjustments, turn an adjustment screw and nothing changed. It sucked to say the least. I put on the Penske with Traxxion's initial ride height & settings and would up with an even better bike. Small adjustments are noticeable and make the bike handle so much better at all speeds (track or street). Worth every penny if you are going to ride this bike hard. Ride height adjustment jacked the rear end up slightly higher putting the bike in a better overall geometry. High speed on southeast tracks is much better now (Road Atlanta, VIR, Barber, etc).
Details of install will be added later...
Sprockets & Gearing for Street & Track
After doing some track days, I quickly found that I was not in the power band all the time and that I just couldn't seem to find the right gear in some turns for the best exit drive. I was watching a lot of guys pull away from me coming out of the turns because the gearing was setup more for street usage and low rpms. I promptly called up superbikesupply in Asheville, NC and got a new DID chain and AFAM sprockets. They are worn out after 1.5+ years of hard use, so I'm putting on a new chain and Driven sprockets very soon, will take some pictures of the installed parts.
Stock setup: 16 tooth front, 46 tooth rear
Ideal setups for me (by track):
Barber: 15 front (-1), 48 rear (+2)
Road Atlanta: 15 front (-1), 46 rear (0)
VIR North: 15 front (-1), 48 rear (+2)
These setups can use the exact same chain and just swapping the rear sprocket and adjusting the chain tension correctly each time. I picked up a used rear sprocket carrier, so I have a 46 tooth sprocket on one and a 48 tooth on the other. I generally take the 48 tooth with me to track days just in case I decide to swap it out and check out the difference. The F4i isn't the latest bike with the highest horsepower, so it's all about keeping the bike in the powerband and maximizing your drive. Ever since swapping the sprockets, I've done much better against the newer bikes on drive. Once I got my corner speeds up, it was a great combination of more speed than some riders and great drive when you want it. I've been riding with NESBA for several years now in the I group. My bike performs well and holds it's own against all types of bikes, 1000RR's, 600's, you name it. It's the rider and bike that determine how you do. I can say that it is really cool to hand see an old school 600cc bike hand a much newer bike it's ass on the track. There's all types of riders and many can make a bike with much less power really fast, I'm still learning for sure. I've seen a guy on an old F4 walk on nearly everyone in I group at Road Atlanta and that bike has nothing topend-wise vs. the other bikes, but he can ride the shit out of that bike.
These tires have been the answer to what I was looking for: more grip on the edge and work great for any type of riding. I get really good wear and can use them for multiple track days without worrying about tire warmers. I've worked with control riders at Barber for several sessions on getting through some corners faster and getting a better drive. The best example of how I like the tires can be summed up like this: I need some help in turn 5 (A-C) at Barber getting a better line and drive out of the corner. I spoke with a control rider at the end of an earlier session and he agreed to help me in the next session. I lined up in the front and went straight out with him. I generally ride fairly easy for a lap to let the tires get good and warm, but I figured screw it, I'd stay as smooth as possible and if I felt the tires slip Id back off. So, I stayed about 5 feet off is tail the next few turns until we got to turn 5. I stayed exactly on his line, faded in on the brakes as he did, and absolutely gave the bike more throttle than I ever have at full lean with my knee on the ground and the tire stuck. I've never gotten that much drive from such a lean angle and I stayed right on his ass. Talk about a great feeling! Smooth throttle to brake transitions, and then easing on the gas again to pick the bike back up and back up to speed. I'm not saying whack the heck out of the throttle with these tires, but they do grip very well and reward smooth throttle inputs. I'm running in the top third of the pack at Barber in I-group with NESBA on an F4i and I can almost guarantee you there aren't many bikes out there like it. Almost all of them are newer and have a lot more power.
My own tire pressure settings:
Many of my experiences and tuning have been based on both the track and the ambient or high temps for the day. These tires can't shed the heat that a race tire can based on the silica based compounds used to offer good temperature range and wet traction for street duty. Keep them in above 30 psi or so starting on a hot day and you will have good results.
Pressures - track - ambient day temps:
Barber: 31 front / 30 rear for temps in low 70's for high
more to be added....
Tire wear examples and how to tune your suspension settings based on the wear:
more to be added...
Last update: 1/31/09