Jump to content

5th Gen VTR1000 fork swap


Guest cdmpc

Recommended Posts

  • Replies 87
  • Created
  • Last Reply
  • Member Contributer

VfrViddy, I bought some lightly crashed VTR forks, the tubes were a little bent but the inner parts were OK. From these, I extracted the fork cap and the damper rod and the rebound piston. The rest of the parts can stay as standard VFR parts, although if you are doing track days you'd get a lot of benefit from new springs (the VTR springs are just as weedy as the VFR) and changes to the shims and damper parts.

My recipe is to use 0.90 kg/mm springs, a Gold Valve for the compression and use the C32 or C33 shim stack they recommend, and re-shim the standard rebound piston with 5 x 0.15 x 17mm shims.

I covered this off in an earlier post http://www.vfrdiscussion.com/forum/index.php/topic/79647-5th-gen-suspension-modifcations/

Link to comment
Share on other sites

  • Member Contributer

Anyone who can compare the vtr spring with the vfr spring?

A litle confusing as to how much the spacer needs to be cut.

I would like my vfr as close to original as possible.

But had my first track day last weekend and damn, I need som front forks That can be adjusted.

If CornerCarver have some lower forks, maybe someone else have the VTR upper forks I need?

Its not a common mod here in norway and I Dont think any members of the vfr-club Norway with 5th gen vfr have done the swap.

The VTR springs are even softer then the VFR. No matter what get new springs for you and the bike.I used the spacer that was in the VTR tubes with the new spring and adjusted all the way out it is just right. I figured I could always take it out and cut it if it was too stiff and didnt get the sag I needed, I would recommend doing the same if you go this route because my bike is considerably lighter then stock and I am 170 lbs without gear.

Link to comment
Share on other sites

Thanks!!
Terry. sounds just like what I need.
As told before, I have a pair of wilbers springs but my lower fork legs are so worn that i beleive they need replacing as well.

Anyone got the fork cap and the damper rod and the rebound piston from a VTR?

Link to comment
Share on other sites

Just read the earlyer post.

Love it!! great job and wonderful information!

i have changed rubber sealings 2 times and know how to get the air out, and meassure the oil level.

but my knowlege stops there.

gold valves, shims stack and re- shim rebound piston?

heelp!!

Link to comment
Share on other sites

  • Member Contributer

http://www.vfrdiscussion.com/forum/index.php/files/file/219-fork-gold-valve-installation/

If you've changed fork seals then you've already done the hard stuff, the rest of the fork is easy. The fork cartridge is easy to disassemble, push the compression valve into the cartridge to expose the circlip, remove that, then extract the compression valve. The rebound piston and rod will slide right out the same way, don't worry there's no parts that will come flying out!

The link above describes how to disassemble the valve bodies and add new shims. You'll need the RaceTech GoldValve part FMGV S2040.

I suspect that kit has enough shims in it to also re-shim the rebound piston (that is in the installation instructions).

All you'll need is some Loctite and some very basic hand tools, patience, and cleanliness.

If you need any advice just ask.

Link to comment
Share on other sites

  • 3 weeks later...

ok..

waiting for parts to arrive next week.

still wondering about my wilbers vfr springs though.

fitting with' the vtr damping rod and cap,

what spacer do I use and how mutch do I cut?

I can compare the length of the the springs + spacer in non compressed condition.

or

I can just cut the spacer from the vfr compared to the longer damper mecanism and cap on the vtr.

if the vtr and vfr forks the same length.

did this make any sense?

Link to comment
Share on other sites

  • Member Contributer

ok..

waiting for parts to arrive next week.

still wondering about my wilbers vfr springs though.

fitting with' the vtr damping rod and cap,

what spacer do I use and how mutch do I cut?

I can compare the length of the the springs + spacer in non compressed condition.

or

I can just cut the spacer from the vfr compared to the longer damper mecanism and cap on the vtr.

if the vtr and vfr forks the same length.

did this make any sense?

The VTR is a shorter fork. I do not recall the Delta. I would use the stock spacer before cutting. If you are heavy it may not be that far off of what you need to get your correct sag dims. Then, if your preload is too much after reassembly, you may need to cut. The beauty is that you have adjustment now at the top of the forks. taking into account that my assembly and weight is different from yours, I had to cut 1 1/2" off my stock spacer, then I added back preload at the adjusters.

Link to comment
Share on other sites

  • Member Contributer

If I recall correctly you are keeping all of the VFR fork and just changing the cap/cartridge to a VTR to get the rebound adjuster? In that case, assuming you were happy with the ride height of the Wilbers springs in the "old" fork, I would measure the difference in length between the two fork caps and shorten the "old" space by that amount. The damper cartridges in the VFR and VTR are the same length so that won't affect anything.That will be the only difference that affects the spring. If you were running the Wilbers spring near maximum on the old preload adjuster, you could compensate by adding say 5mm to the final spacer length for the new set-up.

Keep in mind the part of the cap that bears on the springs is the bottom of the locknut. I would screw the spring preload adjuster to it's mid point on both caps, then measure from the top of the cap to the bottom of the threaded tube on both. I think it should be around a 25mm difference if memory serves me well.

You can replace the spacer with a suitable diameter of PVC pipe, or cut an existing spacer to suit.

I don't think you can't use a 6th gen spring as it is intended for a 43mm diameter fork, whereas the 5th gen is a 41mm.

Link to comment
Share on other sites

my "problem" now is that Wilbers only list the vfr 800 as Rc46.

that is both the 5th gen and 6th gen.

I did notice that the old springs was smaller in width, but never really meassured it.

I also had a skveeky sound when compressing the forks at stand still.

like the springs rubbing on the inside of the forks.

asking my wilbers contact now, and hopefully gets answers tomorow.

maybe I can order a VTR spring if the one i got is wrong.

heh

Link to comment
Share on other sites

  • Member Contributer

5th gen fork = 41mm same as VTR hence swap works. 6th gen fork=43mm so CBR600F4/F4i parts can be used.

Front master with VTR/CBR lowers & brake calipers use CBR600F4/F4i master cylinder, perfect & looks the same as VFR master.

Add 3mm spacers between. VTR caliper mounts & the calipers to get correct alignment on disc. I used 2x 1.5mm alloy washers & superglued them under pressure to the calipers to avoid them falling out when you have to remove caliper to change tyre etc.

Link to comment
Share on other sites

  • Member Contributer

That's a bit I hadn't considered with the VTR lower install on a 5th gen Mohawk. Just so I understand clearly (if I ever do the de-link exercise), are you saying that the combination of 5th gen triples, VTR lowers/brakes and a 5th gen wheel needs the 3mm spacers? I have compared the wheels and the VTR discs are closer together than the VFR, so I guess that would make sense.

I also own a complete VTR and I have fitted CBR954 callipers/master on that, and these are a nearly straight swap except the lower calliper mount on each leg needs a bit of filing to fit the calliper. CBR600, CBR929 and RC51 callipers need the same treatment to fit VTR forks. With the 3mm spacers you may not need to file the VTR legs.

I found the VTR brakes a bit uninspiring, I think Honda messed up the master cylinder size (too small). The 954 brakes are wonderful.

Link to comment
Share on other sites

  • Member Contributer

I did some calculations on this in this thread in 2011, and I think I came out with 2.5mm per side, but 3mm is probably close enough.

When I fit the VTR forks and F4i calipers to my 3rd gen I decided to grind the calipers, rather than the fork lowers--less critical "meat" on the calipers was my reasoning.

Also, IINM, fork springs are the same OD in all RC46, despite the stanchion tubes being slightly larger. In any case, it wouldn't make any difference, so long as there was no interference with other parts. What matters is the rate. In theory, you could have one really strong spring in one fork leg and nothing at all in the other, but I don't think anyone does this. Some bikes did have the compression valving in one fork and the rebound valving in the other. Didn't the early Race-Tech kit for the ST1300 do this?

Ciao,

Link to comment
Share on other sites

  • Member Contributer

I ground the lower fork fitting as I was more comfortable shaving a couple of mm off on the non-load bearing side of the fitting (the calliper is pushing forwards on the leg) than on the outside of the hydraulic cylinder.

I looked up the spring offerings on the Racetech site and they list a different series name 3534 for the 41mm fork and 3732 for the 43mm. I believe this translates to a 35mm OD and 340mm length for the 41mm fork, and 37mm OD and 320mm length for the 43mm fork.

Link to comment
Share on other sites

  • Member Contributer

Correct, on mine, I had to file a small amount off the VTR lower caliper mount so the CBR929 calipers would line up with the bolt holes.

Then added 3mm spacer between legs & calipers to get the disc central in the caliper slot. If you look at my delink pics, they show it in highres detail.

Link to comment
Share on other sites

  • Member Contributer

^^^-On mine, I did very similar, but a little less scientific, and used off the shelf washers from the hardware store.I would guess they are a tenth inch thick.

Works fine. Grinding perfect dimension spacers is on my to do list, but there are plenty of other things more needed to get done first.

Link to comment
Share on other sites

  • Member Contributer

5th gen fork = 41mm same as VTR hence swap works. 6th gen fork=43mm so CBR600F4/F4i parts can be used.

Front master with VTR/CBR lowers & brake calipers use CBR600F4/F4i master cylinder, perfect & looks the same as VFR master.

Add 3mm spacers between. VTR caliper mounts & the calipers to get correct alignment on disc. I used 2x 1.5mm alloy washers & superglued them under pressure to the calipers to avoid them falling out when you have to remove caliper to change tyre etc.

This is the reason on my 5th Gen I went with the 6th Gen triples (direct swap) and the F4I forks (and fender) and de-linked the brakes. I used no spacers on the brakes at all...everything lned up nicely. And I have 43mm forks almost the same length (a little shorter 5-7mm IIRC)...

Matt

Link to comment
Share on other sites

yo..

ok now I have the knowledge I need, I think.

I did the DVS (Digital Valving Search) on Race Tech and recomended shim stack for me is c35

I'm 208 pounds.

so..

what do you think Terry?

should I also re-shim the rebound piston?

Link to comment
Share on other sites

Oh yea.. Oil level recomended was 140mm.

Any reason you did not use gold valve on the rebound Terry?

And.. Not shure if i should drill the hole or not.

I'm thinking not, as that only counts for the forks without rebound adjusting? Or?

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.


×
×
  • Create New...

Important Information

By using this site, you agree to our Privacy Policy.