New Toy!. Got Set Of F4i Forks (guts)

[tinyminds]

Got a set of F4i fork guts for my VFR, in great condition for $40 shipped. I love ebay. Time to have clickers on my front forks!!!

I'll let you know how I like them after I get them on my bike.

[Hobie1dog]

Please enlighten me on what this will do for you. Better spring rate? More adjustability? What years of VFR will your F4i fit?

[2003_VTEC_Rider]

More adjustability on the front end, can't remember if it is Compression or Rebound though.

[Hobie1dog]

More adjustability on the front end, can't remember if it is Compression or Rebound though.

Then my next question is will the complete F4i forks convert over to a VFR? Are they Showa brand?

[SEBSPEED]

More adjustability on the front end, can't remember if it is Compression or Rebound though.

Then my next question is will the complete F4i forks convert over to a VFR? Are they Showa brand?

Yes, forks are the same diameter, but you lose the linked brakes(this applies to 6th gens!)

[Hobie1dog]

More adjustability on the front end, can't remember if it is Compression or Rebound though.

Then my next question is will the complete F4i forks convert over to a VFR? Are they Showa brand?

Yes, forks are the same diameter, but you lose the linked brakes(this applies to 6th gens!)

Cool, don't need no stinkin linked brakes. Are they lighter in weight than the stock VFR forks?

[AB-Oz]

Thats an excellent find and purchase.

I'm still on the lookout for some F3 internals to slot into a mates '99 klingon...

[tinyminds]

More adjustability on the front end, can't remember if it is Compression or Rebound though.

Then my next question is will the complete F4i forks convert over to a VFR? Are they Showa brand?

Yes, forks are the same diameter, but you lose the linked brakes(this applies to 6th gens!)

Actually, my plans are to put these F4i guts in my VFR's tubes, gutting my VFR's tubes. This way I don't have to change anything on the outside. They should screw directly into my existing fork sliders.

[tinyminds]

More adjustability on the front end, can't remember if it is Compression or Rebound though.

Then my next question is will the complete F4i forks convert over to a VFR? Are they Showa brand?

F4 forks bolt up to 6th gen, F3 forks bolt up to 5th gen. Below that I donno.

[Trace]

Yeah, I did this with F3 forkguts on my 5th Gen, but in conjunction with Racetech springs, comp & rebound valves as part of a full fork rebuild/upgrade. The F-stuff gets you rebound control only (brass clickies thingos in the center of the preload adjuster screw thingy).

Jason, I assume you'll be using the F valves, essentially putting the whole cartridge (as is) in your forks? Should work just fine, AFAIK.

[tinyminds]

Yeah, I did this with F3 forkguts on my 5th Gen, but in conjunction with Racetech springs, comp & rebound valves as part of a full fork rebuild/upgrade. The F-stuff gets you rebound control only (brass clickies thingos in the center of the preload adjuster screw thingy).

Jason, I assume you'll be using the F valves, essentially putting the whole cartridge (as is) in your forks? Should work just fine, AFAIK.

Yeah thats the plan for now, by the time i actually get around to ripping my forks off the bike, might wait til after bike week, I might order the racetech springs, we will have to see how funds holds out til then.

[Baileyrock]

Yeah, I did this with F3 forkguts on my 5th Gen, but in conjunction with Racetech springs, comp & rebound valves as part of a full fork rebuild/upgrade. The F-stuff gets you rebound control only (brass clickies thingos in the center of the preload adjuster screw thingy).

Jason, I assume you'll be using the F valves, essentially putting the whole cartridge (as is) in your forks? Should work just fine, AFAIK.

Actually, the F4/F4i us a larger bottom bolt to fasten the bottom valve(2mm diff.) and unless you drill out the bottom of the VFR lower fork leg you will have to use the VFR valve body(I think that's the comp. valve).

Also the rebound tube body is around 12mm shorter than the VFR too, but it still works. Not sure what effect it actually has on it! :warranty:

[tinyminds]

Yeah, I did this with F3 forkguts on my 5th Gen, but in conjunction with Racetech springs, comp & rebound valves as part of a full fork rebuild/upgrade. The F-stuff gets you rebound control only (brass clickies thingos in the center of the preload adjuster screw thingy).

Jason, I assume you'll be using the F valves, essentially putting the whole cartridge (as is) in your forks? Should work just fine, AFAIK.

Actually, the F4/F4i us a larger bottom bolt to fasten the bottom valve(2mm diff.) and unless you drill out the bottom of the VFR lower fork leg you will have to use the VFR valve body(I think that's the comp. valve).

Also the rebound tube body is around 12mm shorter than the VFR too, but it still works. Not sure what effect it actually has on it! :warranty:

Hmm glad to know. Guess i'll be drilling stuff out after I verify everything.

[Baileyrock]

Yeah, I did this with F3 forkguts on my 5th Gen, but in conjunction with Racetech springs, comp & rebound valves as part of a full fork rebuild/upgrade. The F-stuff gets you rebound control only (brass clickies thingos in the center of the preload adjuster screw thingy).

Jason, I assume you'll be using the F valves, essentially putting the whole cartridge (as is) in your forks? Should work just fine, AFAIK.

Actually, the F4/F4i us a larger bottom bolt to fasten the bottom valve(2mm diff.) and unless you drill out the bottom of the VFR lower fork leg you will have to use the VFR valve body(I think that's the comp. valve).

Also the rebound tube body is around 12mm shorter than the VFR too, but it still works. Not sure what effect it actually has on it! :warranty:

Hmm glad to know. Guess i'll be drilling stuff out after I verify everything.

Jason,

I don't know if you can actually just drill it out, it may need a seat machined in it also. They use the same valve so it shouldn't effect your damping to use the VFR valve assy. :thumbsup:

ps I don't know if your changing springs while your in there, but if not you need to know the F4i runs .660 kg springs where as the the F4 and VFR use the .740 kg springs! B)

[Guest]

yea, I was gonna mention - the F4 weighs what, 140 lbs less than VFR - to do it right, probably need whole new internals, springs, valves, etc. I think the shorter F 4 fork tube, if you use it, would be same as 'dropping the forks' in triple clamps, which is often done to quicken steering. Or is it the opposite?

not totally simple 'bolt in'. Since VFR is one of Hondas 'flagship models' - they should see fit to offer an upgrade - at least a modified version of F4 setup,: better, from 954. yea, THAT's gonna happen.

[Baileyrock]

yea, I was gonna mention - the F4 weighs what, 140 lbs less than VFR - to do it right, probably need whole new internals, springs, valves, etc. I think the shorter F 4 fork tube, if you use it, would be same as 'dropping the forks' in triple clamps, which is often done to quicken steering. Or is it the opposite?

not totally simple 'bolt in'. Since VFR is one of Hondas 'flagship models' - they should see fit to offer an upgrade - at least a modified version of F4 setup,: better, from 954. yea, THAT's gonna happen.

goodhawk,

Actually the internals of both the F3(5th gen) and F4/F4i(6th gen) have successfully been installed without issue. This provides rebound adjustment (keep pre-load too) to the stock VFR forks and while most people are in there they will re-spring and re-valve (change shim stack) at the same time. They say rebound is the most important adjustment to have if you only have one. :goofy:

:thumbsup:

[tinyminds]

Going to do racetech springs while I'm in there. Wasn't aware the valve assembly was the same between the bikes, glad to know though. Like I said above I'm not going to mess with changing stuff out #1 til i get my springs in, and #2 until after bike week, and until I start tearing stuff apart I have/had no clue what kinda differences I would be running into. All I knew is it does work, and it will get changed no matter what type of machining has to be done if necessary, if I can avoid machining stuff of course I will. I'll take pics and compare them to HS's writeup on the 5th gens when I get around to it, any differences conversion from the 5th gen I'll post up. Thanks again for info on valve ass. likeness BR. :goofy:

[Baileyrock]

Here's what I'm talking about.

The VFR (bottom) uses a smaller bolt through the bottom of the fork leg, but I did see that they(Honda) seems to machine the same size I.D. in the bottom of the fork leg where you could just drill the hole out to fit the larger bolt and still have a machined flat sealing surface. :thumbsup:

Don't know if you should use it though, as you can see the F4/F4i bolt is hollow and is used to pass oil into the Comp. adjustment circuit(I think), this could act as a big bleed to help out hurt the damping. :goofy:

[tinyminds]

Is that the oil lock peice for the VFR/CBR? If so why in the hell is there a oil passage to release the oil down there? The pic is just confusing me, use to having parts laid across a table :P Backing up... you having them both in front of you, does it appear that I can do this without drilling the bottoms? I don't prefer drilling stuff on the VFR factory stuff if possible.

[thx1139]

Is it me, or are you guys making a lot of extra work for yourselves?

Why wouldn't you just swap out the compression valve tower for the one that fits the fork lower you are going to use?

Small bolt lower = small bolt tower.

Other than the bolt size they are virtually the same part.

It is correct that the drilled bolt comprises part of the F4 compression adjustment. The adustable compression circut requires two special bolts per leg; the drilled allen which bolts the catridge to the fork lower, and a hollow allen bolt holds the compression valve & shims on the compression valve tower. These are solid in the non-compression adjustable VFR lower.

Non-comp adjustable forks use a fixed bleed somewhere on the compression valve; either a small hole or notch(es) machined into the valve, or a bleed shim at the base of the shim stack. If you try to use F4 compression valves with VFR sliders you must be sure the arrangemnt incorporates a low-speed bleed somewhere.

[thx1139]

There is another area that deserves scrutiny when mixing and matching fork guts.

When swapping internals from another fork into VFR tubes, pay attention to the different part lengths.

Fork top-out is supposed to be limited by the short top-out springs around the cartridge. If you swap to a cartridge rod that is much shorter, or a shorter cartridge body or assembly, there is a danger of the fork topping out against the rebound valve inside the cartridge instead of the top-out spring. Ultimately this could destroy the cartridge.

Sometimes, even with similar length forks, the top-out spring is located further down on the cartridge body, to allow for the added height of the rebound valve holder/needle on reb. adjustable rods.

While assembling one of these "mongrels", check that the modified fork is topping out against its T.O. spring at full extension. Pull on the lower until you can feel the spring flexing at the limit of travel. If the lower tops out hard it may be assumed the rebound valve/rod inside the cartridge is making contact before the spring.

[Baileyrock]

Is it me, or are you guys making a lot of extra work for yourselves?

Why wouldn't you just swap out the compression valve tower for the one that fits the fork lower you are going to use?

Small bolt lower = small bolt tower.

Other than the bolt size they are virtually the same part.

It is correct that the drilled bolt comprises part of the F4 compression adjustment. The adustable compression circut requires two special bolts per leg; the drilled allen which bolts the catridge to the fork lower, and a hollow allen bolt holds the compression valve & shims on the compression valve tower. These are solid in the non-compression adjustable VFR lower.

Non-comp adjustable forks use a fixed bleed somewhere on the compression valve; either a small hole or notch(es) machined into the valve, or a bleed shim at the base of the shim stack. If you try to use F4 compression valves with VFR sliders you must be sure the arrangemnt incorporates a low-speed bleed somewhere.

You are Dead On will all your info thx1139! :thumbsup:

No reason I can think of to use the F4 tower because like you say there's no difference in the two and unless you use the F4 lower leg you can't take advantage of the Comp. adjust. system, but I'm no expert so I'm just providing answers where I can. :goofy:

Also from your second post on the Top out factor, it was for this reason that I didn't have Phil @ Aftershocks install the F4 internals when he built my forks. The 12mm shorter cartridge rod was a concern to both of us, but it's been installed many times. I was thinking" how ofter would I top out the VFR forks?" a lot and I love wheelies too! :wub: