F4i Front End On 5th Gen?

[AndyJ]

I'm starting to do some research on fork upgrades for my 5th gen. I've seen a few references to using F4i Forks/Triples/brakes from BaileyRock & Jon (BR wait til you're feeling better to respond). Not a whole lot of info in searches that I could find yet. It 'seems' like a relatively inexpensive way to upgrade and gain more adjustability in front. I'm not a big fan of LBS, so I wouldn't miss it either.

Anyone have any info about dimensions, stem compatibility, etc?

Is this basically a bolt-up, or would I need to have some machining done? Any advantage to using VTEC vs F4i stem and triples?

[CornerCarver]

Andy,

The F4i forks are the same diameter as the 6th gen. I think it would be an excellent (and inexpensive if sourced properly) upgrade for a 5th gen. You would need to get 6th gen upper and lower triple clamps as well as handle bars and switch gear. You would also need to de-link the brakes.

Another direction for you to look is to get a set of F3 forks and use the internals to upgrade your 5th gen forks. You would not have to do much additional work but you also not get the benefit of stiffer (43mm vs 41 mm) forks or the potential of upgrading the brakes. The linked brakes on the VFR are really not that bad when you have good pads, fresh fluid and they are bled properly.

Plenty of help here whether you go with a simple F3 upgrade or go alll out put together an USD set up. keep us up to date on which direction you choose.

keith

[Veefer800Canuck]

Definetly use the VTEC triples on the 5th gen with the F4i forks. You'll keep your VFR-like geometry, I am going to guess that the F4i triples have less offset which would net you more trail, more straight-line stability, better self-centering of the front end, with some noticeable loss of "flickability". You'll basically have to muscle the bike to lay down into the corner more, and that might be troublesome.

I had some of these issues with my RC51 front end, but compensated by dropping the front (forks were shorter than stock) and raising the rear (by shimming the upper shock mount) and also by having wider handlebars, thus increasing my input leverage to the front end.

Net result in my case was a bike that was more planted, and didn't require a lot of turn-in effort, but if you weren't completely familiar with the bike, you may/may not run a tad wide on corner exits, depending on the road. Just a slight adaptation in riding style and awareness fixes that.

But in your case, with the conventional CBR F4i fork, definetly use the 43mm VTEC VFR triples.

Numbers I've looked at just now all over the net suggest 25.5' rake and either 95 or 100mm of trail for either the 5th gens or the VTECs, so they are absolutely very close as a family.

CBR is 24' and 96mm, so you kick that out another 1.5' and your 96mm probably becomes ~106 or maybe ~110mm of trail??? (just guessing here........)

[FotoMoto]

I adopted an F4i front end to a SuperHawk about 5 or 6 years ago. The VTR front end is very similar to the VFR so I knew it would be a relatively easy swap when I tried it on my current 4gen.

It would be a bolt on for the 5/6 gen. 5gen would need new triples, 6gen can use stockers. LBS would be eliminated. Length is a tad shorter (technical term) and I found VTEC triples felt better than F4i triples which have a tad less offset. You can use stock wheel and rotors. I believe VFR axle and spacers work too but don't hold me to that. Steering bearings are the same for all models mentioned.

[FotoMoto]

I forgot to mention that you need new springs. Mine came with aftermarket heavier springs so I don't know how well the stock F4i would work. My guess is that they would be too light in typical Honda fashion.

[AndyJ]

Thanks for the info everybody!! Going to start parts-collecting soon once I get my cage ready for winter.

I'm expecting to need heavier springs at both ends as part of this. I'm ~210 with gear, so I'm planning get with Jamie this winter as part of my upgrade.

[MikeOConner]

Andy,

The F4i forks are the same diameter as the 6th gen. I think it would be an excellent (and inexpensive if sourced properly) upgrade for a 5th gen. You would need to get 6th gen upper and lower triple clamps as well as handle bars and switch gear. You would also need to de-link the brakes.

Another direction for you to look is to get a set of F3 forks and use the internals to upgrade your 5th gen forks. You would not have to do much additional work but you also not get the benefit of stiffer (43mm vs 41 mm) forks or the potential of upgrading the brakes. The linked brakes on the VFR are really not that bad when you have good pads, fresh fluid and they are bled properly.

Plenty of help here whether you go with a simple F3 upgrade or go alll out put together an USD set up. keep us up to date on which direction you choose.

keith

Cornercarver, would it matter if one used F3 or F4 fork internals to upgrade the existing 5th Gen forks? I guess you would need the fork caps too from the donor froks too? I just picked up a wrecked VFR about a year ago that I have been rebuilding it for a while and this sounds like a great upgrade.

[Baileyrock]

you need F 3 internals on 5th gen Forks as they are the same diameter

and F4 internals on a 6th gen as they are the same diameter. Fork Caps are the issue .

BR

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