Can I Use The 3rd Gen Front Wheel For Vtr Fork Swap

[FinnRC36]

I'm doing the VTR1000F front fork swap to my '91 RC36 and I was wondering will the original wheel and fixed rotors work with the CBR900RR brakes I'm going to use or do I have to find some floating rotors and a matching wheel for it? Also I'm interested in modifying the fork cartridges but I haven't ever disassembled any cartridge and woul like to see some kind of instructions on how it's done, with pictures preferably. Can you guys help me out here? Thanks!

[keny]

Terve, and nice to see some countrymen on this board :cool:

Well I´m sorry I cant tell you for sure, but I think its possible to use stock wheel, as brake disc have same diamerer, and spacing should be close. I wounder if you just swamp the legs or complet fork whit triples? both are 41mm so just legs should work.

Hope you do a writeup on this whit some pics. Sounds intresting, and diffrent.

I´m sure someone can com up whit some mesurments here?

[JamieDaugherty]

You might be able to use that wheel if you could get the correct size rotors for it. I'm pretty sure some years of ST1100 had that mounting pattern and were larger OD, so that would be where I would start. I use the EBC Brakes catalog to cross reference this kind of thing. Go to the very back where they have the application guide - it gives a bunch of info like model/year/rotor size/etc. If you find something that looks like it might work I'd call their tech line. Not all of the rotors in their catalog are still available.

The rotor size is really just one piece of the puzzle. You will also need to make sure that the spacing between the rotors is the same as well. I don't know that off the top of my head but I can get it for you. The axle might cause you fits too, check to see that it's the same diameter. You'll need to use the axle that goes with those forks. Luckily there are usually bearings available with the same OD (so they fit in the wheel) and larger/smaller ID's to accommodate.

The fork cartridges aren't too bad. Once you pull out the damping rod bolt (at the very bottom of the fork) the whole thing comes right out. You don't need to remove the spring first, I like to leave it all assembled including the fork cap and remove the entire guts as one piece. Once out you can take the fork cap and spring off. The compression valve is at the bottom of the larger tube. Push it inwards to expose a retaining ring. Remove that ring and use the smaller rod to push the valve assembly out the bottom. Make sure to have the nut off the smaller tube (the locknut for the fork cap) and you can remove the rod with the rebound valve. At that point everything is apart!

[FinnRC36]

Morjesta vaan, for keny.

I'm swapping the fork tuber as an assembly and using the original triples as there is no need to replace them. The original rotors are the same diameter as the ones in the VTR1000F and the mounting points of the calibers match too so the diameter isn't a problem. However the stock rotors on my VFR are non-floating and the ones in the CBR900RR are floating and I'm unsure if that could cause some problems?

Otherwise the swap is simple bolt on and well described at this forum and in http://www.vsource.org/VFR-RVF_files/VTR1000F-forks.htm. The only thing different in my project than discussed here on the forum is that the brakes are from a 1999 CBR900RR which is a 918cc bike rather than the 929/954 recommended. But my research indicates that the brake calibers are indentical in appearance and use the same pads but have some internal differences. In some thread it was mentioned that these calibers are available in two configuration, the early and the late, so I guess mine are of the early type.

Also more info on the disassembly of the fork cartridges is welcome and also on what kind of modifications you recommend on the valving? I intend to use the original valving from either the VFR cartridges or from the ones in the VTR with HMAS valves. Any advise on that is really appreciated!

Maybe after I'm done I get around to write it up also.

[The Phantom]

Otherwise the swap is simple bolt on and well described at this forum and in http://www.vsource.org/VFR-RVF_files/VTR1000F-forks.htm.

The owner of that site is a member here - look up JZH and send him a PM.

And welcome to VFRD :rolleyes:

[FinnRC36]

Otherwise the swap is simple bolt on and well described at this forum and in http://www.vsource.org/VFR-RVF_files/VTR1000F-forks.htm.

The owner of that site is a member here - look up JZH and send him a PM.

And welcome to VFRD

Thanks.

I already gathered from his posts that it's his bike. But he uses a 4th gen front wheel in his bike and 4th gen has floating rotors. In the article he does presume that you could use the 3rd gen front wheel also but I was looking for a confirmation on the subject.

I'm most interested in knowing what is the reason to use floating rotors vs. non-floating because that is unclear to me. I was wondering if it has something to do with the type of brake calibers? Although both 3rd and 4th gen bikes have the same calibers while only 4th gen has floating discs. But do the 4 piston calibers require floating discs? I'm an engineer by trade so bear with me and my curiosity :rolleyes:

[JamieDaugherty]

As long as the rotors are the same diameter and spaced apart the same distance it won't matter if they are floating or non-floating. Floating rotors are better for performance but are functionally the same.

[SAFE-T]

I always thought the idea behind the floating rotor was to allow for thermal expansion of the rotor under prolonged heavy braking. Probably not really necessary for the street, but a nice bit of trickle-down performance all the same.

[keny]

As long as the rotors are the same diameter and spaced apart the same distance it won't matter if they are floating or non-floating. Floating rotors are better for performance but are functionally the same.

as for the spacing this link will help. Close enough I would say.

[JamieDaugherty]

I always thought the idea behind the floating rotor was to allow for thermal expansion of the rotor under prolonged heavy braking. Probably not really necessary for the street, but a nice bit of trickle-down performance all the same.

That's exactly right. It's probably a good idea but for the street I'm not sure you'd notice.

As long as the rotors are the same diameter and spaced apart the same distance it won't matter if they are floating or non-floating. Floating rotors are better for performance but are functionally the same.

as for the spacing this link will help. Close enough I would say.

It looks like you'd have to machine the front wheel on the 86-87 VFR, I thought I saw somewhere that it's 112mm. The rotor spacing for the F2's 125mm.

[JZH]

I already gathered from his posts that it's his bike. But he uses a 4th gen front wheel in his bike and 4th gen has floating rotors. In the article he does presume that you could use the 3rd gen front wheel also but I was looking for a confirmation on the subject.

I'm most interested in knowing what is the reason to use floating rotors vs. non-floating because that is unclear to me. I was wondering if it has something to do with the type of brake calibers? Although both 3rd and 4th gen bikes have the same calibers while only 4th gen has floating discs. But do the 4 piston calibers require floating discs? I'm an engineer by trade so bear with me and my curiosity :cool:

There could be a cosmetic reason, of course! The 3rd-gen had fixed rotors/discs and floating calipers; the 4th-gen had floating rotors and floating calipers; the VTR1000F had floating rotors and fixed calipers. So, the only combination not represented is fixed/fixed, which is what you're contemplating... :cool:

The fixed and floating OEM rotors are generally different thicknesses, with the former being (I think) 1mm thicker than the latter. My fear would be that, although the rotors seem to line up fairly closely, is that the fixed/fixed combination wouldn't be able to cope with the different disc thickness and any slight alignment differences, which could mean your brake pads won't wear evenly, or could even bind. For that reason, I would suggest you find a 4th-gen floating rotor type front wheel to use for your conversion. HTH.

Ciao,

[keny]

As long as the rotors are the same diameter and spaced apart the same distance it won't matter if they are floating or non-floating. Floating rotors are better for performance but are functionally the same.

as for the spacing this link will help. Close enough I would say.

It looks like you'd have to machine the front wheel on the 86-87 VFR, I thought I saw somewhere that it's 112mm. The rotor spacing for the F2's 125mm.

The link is for 3rd vs 4th gen rotor spacing. I had plans to put a 4th gen fork on my 87 befor I sold it and got a 5th gen.

Had a PVM wheel whit spacers ready and all, but all gone now.

[keny]

I already gathered from his posts that it's his bike. But he uses a 4th gen front wheel in his bike and 4th gen has floating rotors. In the article he does presume that you could use the 3rd gen front wheel also but I was looking for a confirmation on the subject.

I'm most interested in knowing what is the reason to use floating rotors vs. non-floating because that is unclear to me. I was wondering if it has something to do with the type of brake calibers? Although both 3rd and 4th gen bikes have the same calibers while only 4th gen has floating discs. But do the 4 piston calibers require floating discs? I'm an engineer by trade so bear with me and my curiosity :cool:

There could be a cosmetic reason, of course! The 3rd-gen had fixed rotors/discs and floating calipers; the 4th-gen had floating rotors and floating calipers; the VTR1000F had floating rotors and fixed calipers. So, the only combination not represented is fixed/fixed, which is what you're contemplating... :cool:

The fixed and floating OEM rotors are generally different thicknesses, with the former being (I think) 1mm thicker than the latter. My fear would be that, although the rotors seem to line up fairly closely, is that the fixed/fixed combination wouldn't be able to cope with the different disc thickness and any slight alignment differences, which could mean your brake pads won't wear evenly, or could even bind. For that reason, I would suggest you find a 4th-gen floating rotor type front wheel to use for your conversion. HTH.

Ciao,

Well I would at least try the 3rd gen wheel before buying a 4th gen wheel. If they dont line up correct then take the 4th gen wheel route. And if they line up so you can space callipers then the 3rd gen wheel also work. Even 4 piston calliper is fixed, the pistons allow some lineup error.

I also have to dissagree whit the fact that a slight miss angling will couse the pads wound wear uneven.

I had a Kawa ZX9R fork whit fixed 4pot callipers on whit 1,5mm missangled rotors, and the pads wear was werry even.

The only problem come when one side starte to grabb, so the wheel wount run free.

And also a semi floated brek disc, as all street floated are, dont allow side movment of some mm as the full floated that are used for racing.

[flyguyeddy]

see my build thread.

vtr1000 lowers, 3rd gen wheel, f4i calipers, stock 3rd gen rotors.

seems to work just fine have to space the calipers inward some.

i dont know how it works on the street, but it sure stops nice in my garage!!!

EDIT: picity pic.

http://i16.photobucket.com/albums/b5/Flygu...es/DSCN0459.jpg

[FinnRC36]

see my build thread.

vtr1000 lowers, 3rd gen wheel, f4i calipers, stock 3rd gen rotors.

seems to work just fine have to space the calipers inward some.

i dont know how it works on the street, but it sure stops nice in my garage!!!

EDIT: picity pic.

http://i16.photobucket.com/albums/b5/Flygu...es/DSCN0459.jpg

I've actually already read the thread, once or twice :D I only asked cause I gathered from your thread that you hadn't already tested your setup in practice.

By the way, I'd be really interested in knowing what did you end up using as the compression and rebound shim stacks for the fork internals? I've ordered Öhlins 8.5N/mm (0.87kg/mm) springs for my front end and it's quite close to what I've been reading you use in your bike. I've followed your thread about reshimming for 0.90kg/mm springs but if I remember correctly you haven't written what you ended up with.

[flyguyeddy]

see my build thread.

vtr1000 lowers, 3rd gen wheel, f4i calipers, stock 3rd gen rotors.

seems to work just fine have to space the calipers inward some.

i dont know how it works on the street, but it sure stops nice in my garage!!!

EDIT: picity pic.

http://i16.photobucket.com/albums/b5/Flygu...es/DSCN0459.jpg

I've actually already read the thread, once or twice :D I only asked cause I gathered from your thread that you hadn't already tested your setup in practice.

By the way, I'd be really interested in knowing what did you end up using as the compression and rebound shim stacks for the fork internals? I've ordered Öhlins 8.5N/mm (0.87kg/mm) springs for my front end and it's quite close to what I've been reading you use in your bike. I've followed your thread about reshimming for 0.90kg/mm springs but if I remember correctly you haven't written what you ended up with.

to tell you the truth, i dont think i wrote it down. but i used what someone else told me to use so ill get to work to try and find it (since ill be re-using the specs for my 86).