CBR600F3 fork internals in SV forks?

Hi all,

Just been reading about transplanting the cartridges from a cbr600 into standard sv forks. Sounds like a simple, cheap way to improve the sv forks. Can anyone confirm if this is:

a) possible
b) sensible
c) more hassle than it's worth

Many apologies if this has been covered in the past.

[yorkie_chris]

Good mod by all accounts. You can then valve those to work near as damnit to a properly sorted GSXR setup.

But, I've not done it myself. Have a google-fu and see what you can find

Have a word with Mister-C, he was doing something along those lines

I am in the middle of doing this fork swap, but am in the United States.

It seems to be going pretty well so far. I have pretty high expectations for it. The valving in the CBR forks is supposed to be excellent. I am having a tuner restack the shims and going to heavier springs.

In the main, the forks go together easily. Both the forks are Showa, so everything slides right together. This will allow clipons above the triples, which is what I've wanted for riding position.

I'd rather not do the whole GSXR front end swap, as don't think I need or want forks that massive. 41mm conventional forks do me fine. Also, one doesn't need to deal with speedometer mods, front wheel swaps, fenders and the like.

The forks these are replacing are gen1 forks with Race Tech internals.

[yorkie_chris]

Are they 20mm cartridges in F3?
You know anything about the valving in them? Could you post up (or PM) what stack is going into valves?


I can see the advantage of not swapping wheels and messing with speedo etc. but GSXR brakes are still superior.

I'm not doing the actual valving. Someone else is. The external diameter of the cartridges looks to me about 20mm.

The CBR internals are a common swap on VF Honda Interceptors. Jamie Daugherty does quite a few of these, being the reigning expert on VF suspension. Therefore I am giving the forks to him to do the work, as he's done a lot of these CBR600F3/something else Frankenstein forks.

What I have done this far is taken apart an SV fork and a CBR fork. I suppose I could just put them back together and guess that the valving will be OK. From the racers I know that have used CBR fork internals they have really excellent valves and the damping should be close enough, but since I had them apart... and it's November in New England.... I thought I'd send them out for an expert to look at.

The CBR internals are also a common swap for some modern Triumphs and, I think, the Versys and the Honda Hawk. The Hawk guide is pretty much the same for doing the swap on the SV. I haven't found really great information anyplace on the web but it's plain as day when you take them apart as to to how they should go back together. If you are at all mechancial you should be able to do this.

F3s are getting pretty long in the tooth, so you could pick up a set cheap, this is a whole lot cheaper than doing any other real surgery to the bike besides Race Tech emulators, which actually work pretty good.

This swap will add both rebound adjustment and preload adjustment to the fork in one move, along with true cartridge damping.

[yorkie_chris]

So do you use caps from CBR in the SV stanchions?

On 1st gen bike you just use inner tubes from F3 and mate them with outer sv legs.

Originally Posted by zadar

On 1st gen bike you just use inner tubes from F3 and mate them with outer sv legs.

Correct,

in another way of saying this, you pretty much just use the SV650 lower legs, oil seal, dust wiper and outer bushing.

You use the CBR caps, internals, inner legs/uppers and inner bushing.

The link, above, to the Hawk site has a pretty clear diagram from what to use from each fork. It works the same with the SV as it does with the Hawk. The only caveat is that I'd say to use SV seals and upper bushing, but this would be clear if you were looking at the fork. It's an easy fit.

It seems like a good mod to me, since it allows me to use clip ons which can be adjusted for both height and angle, and allows me to have better damping than I otherwise would. I'm also lucky to have someone like Jamie that really is a specialist in damping curves for these forks, but I think the CBR guts are pretty good.

He said that it wasn't worth upgrading Showa three port pistons to Race Tech Gold Valves in the CBR fork because the piston design was so good. Personally, since I am not hauling my SV down from 160 MPH before diving into corners I don't think I need upside down forks. Plus, it's something a little diffrent that doesn't scream out squid like that GSXR front ends kind of do.

[yorkie_chris]

Those big port showas are similar to gold valve. Some even say gold valve flows too well, but I'm not sure I get that.

Depends which type of piston it is. Look familiar?

Originally Posted by taxonomy

that doesn't scream out squid like that GSXR front ends kind of do.