R6 Fork Install, Another One

[bd43]

Well, I finally pulled the trigger and did the R6 fork mod (http://www.600riders.com/forum/fz6-mods/28956-r6-fork.html) on my 2007 FZ6. If you saw my R6 fork comparison post, then you knew it was coming. I got trigger happy with the camera so I thought I might as well post them with some explanations from the pictures and of some modifications that I did to mine.

To do this mod, and it has been mentioned a few times on this form (http://www.600riders.com/forum/fz6-mods/15252-r6-fork-mod-would-work.html) you need the minimum:

- R6 forks (mine is a parted out 2003)
- R6 front wheel axle (to match the year of fork)
- R6 front wheel axle bolt (to match the axle)
- dako81's (Brad) awesomely machined from RyanK spec'd R6 fork kit which consists of:
2 stainless steel wheel spacers (collars)
2 front fender brackets
2 rear fender brackets
4 stainless steel brake caliper spacers
2 M6x10 button head hex socket screws (these should really be 15mm long)
2 M6x20 flat head hex socket screws (these could be 25mm long)
2 M6x12 flat head hex socket screws (these could be 16mm long)
2 M6 nylock nuts
4 caliper spacers (washers which I didn't bother to measure)

- and tools, various sizes of hex sockets including the 19mm for the front axle, metric sockets, wrenches, phillips screw driver, and CNC machine (okay, not really).

The first thing you need to do is cut up slots in the front fender. I wasn't overly crazy about doing this but the fork upgrade outweighs this small sacrifice any day, and besides, even if you return the bike back to its original equipment, the slots are not easily visible without looking really hard for it. The reason for the slots is the R6 fork front fender mounts sit higher up on the legs than then ones on the FZ6.


To make this task easier, I took the cut-out template and printed it onto a mailing label, then affixed it to the fender.


I cut some areas away from the label before applying it to the fender to make it easier to align it.


Using a 1/8" drill, I piloted a hole on the center mark of the half circle at the top of the cut-out.


I then enlarged the hole with incremental steps of larger drills. With a razor saw, I cut inside the line leaving ample space for error and removed the cut-out. Using a Dremel (115) high speed carbide cutter, I got as close to the line as I dared and then finished the rest off with flat and round files.


Peel away the cut-out template and the slot looks very acceptable, even for the anal retentive like me.


Mount the front and rear fender brackets on the R6 legs.


I kept the legs together with the axle in place. The fender is placed on the legs while I checked the dry fit. If I wasn't a picky person, the rest of this installation would have been completed on this same day.

The fender as it sits on the FZ6 fork legs has a gap between it and the fender large enough to pass a 1/4" drill through it.


With the original fender brackets, I felt the fender was too close to the legs for my liking. If I tried to manipulate the position of the fender to attain a descent enough of a gap, the fender would either be under tension or not run parallel to the legs, messing up the line. I used some cardboard as spacers to maintain a gap between the fender and the R6 legs and in doing so felt the rear brackets could be shorter; 1/8" shorter to be exact.

 

[bd43]

So I machined out a new set of rear brackets 1/8" shorter, and while I was at it, I made the surface area of the fork end of the bracket a larger 1/2" diameter.




Remounting the fender for a dry fit with the new rear brackets, the gap and line look better, IMO.


Here are a couple more shots of the dry fit to better understand the need for the slots and the placement and orientation of the front and rear brackets. The package came with 2 M6 nylock nuts for the rear fender brackets. Since the M6x20 flat head hex socket screws did not protrude beyond the nuts to make the nylocks work effectively, I opted to reuse the FZ6 flanged M6 nuts.


Note the use of the M6x10 button head hex socket screw and the M6x20 flat head hex socket screw.


The M6x10 button head hex socket screw was too short, so I ordered a set of the M6x30 flanged cap screws like the rear ones that came on the FZ6 and will cut them to 15mm length.

A couple of final notes concerning the fender mounting. The front brackets are mounted to the legs with the M6x14 flat head hex socket screws which are inaccessible once the fender is on. Getting the fender alignment correct (personal taste) before tightening down the brackets can take a few tries. I would suggest starting out with the brackets 12mm from the leg to the edge of the bracket.


Secondly, the rear metal inserts should be relocated from the outside position of the rubber grommet to the inside.


Once the fitment is good, note the position of the front brackets, remove fender, and blue Loctite the front fender M6x14 flat head hex socket screws. Place the fender back on and attach the rear brackets.

Once the gap and alignment is to your satisfaction, snug the M6x20 flat head hex socket screws and M6 nuts, remove one of the M6x15 flanged cap screws, apply some blue Loctite and refasten and tighten. Do the other M6x15 flanged cap screw. Now remove the M6 flanged nuts, apply blue Loctite to the exposed M6x20 threads, spin the M6 nuts on and tighten.

Side Bar: Check your rear flanged nuts holding the fender on, mine were loose when I took them off. Another season and they would have been gone. Re-tighten them or better yet, add some Loctite too.

Now slide the fork assemble up the triples and align the fork tube flush with the top triple. The top cap on the fork tube should exposed from the triple.

 

[bd43]

So I mentioned in my R6 comparison post how short the R6 wheel axle was and having that gap of 9mm between the end of the axle and the face of the right fork leg.

Fred mentioned it in his R6 fork write-up and I'm going to re-mention it here. The front wheel axle bolt is almost 23mm in length, and with the 9mm gap, only 14mm of thread would be used to hold the axle to the right leg.


That's almost half the bolt thread not being used, and for me that was a little uncomfortable knowing this. To me, that bolt tightened to spec sandwiches the whole wheel assembly from the lip on the left side of the axle, the left spacer, the front wheel shaft, the right spacer, firmly and squarely to the right leg. This setup ensures that the face of the right spacer is partly contributing to the support of the axle to the leg reducing the moment load on the axle, IMO.

To compromise and get a few more threads holding the axle firmly, I first looked at finding another compatible axle. I went to a motorcycle used parts place, looked in the Honda, Kawasaki, Suzuki, and Yamaha bins. All I got was two greasy hands and a wasted trip. I then decided to use the existing R6 axle, and on the left side, use the original FZ6 spacer. This would give me an extra 3.3mm on the bolt side. I needed to use the R6 mod spacer on the right side as it controls the proper spacing of the wheel from the right leg. What about the left leg? In order to keep the overall spacing between the two legs, I had to machine out a 3.3mm or 0.127" spacer that would slide over the bigger diameter of the R6 axle.


The final result, this spacer ring has an OD of 1.36" and an ID of 1.104". When the spacer is stacked on top of the FZ6 spacer, it is the same height as one of the R6 mod spacers.




On the R6 leg, you can see the purpose of the spacer ring.




And the additional 3.3mm of axle to the right leg while the lip of the left side of the axle is no longer flush to the face of the left leg.


With the axle, spacers, and the front wheel in place, note now the gap is around 5mm from the original 9mm.

 

[bd43]

This is easily 3 more engaged threads on the axle bolt. I managed to torque the bolt to 60ft•lbs from the factory spec of 66 ft•lbs. I didn't feel confident enough to add another 6 ft•lbs but am still happy with the results.

Almost done, just need to remount the brake calipers with the spacers place between the calipers and the legs.


The finished product, and yeah, I left my reflectors on. Call me a safety nut, and it's a vehicle regulation around here.


Finally, as I suspected, the clearance from the fender to the wheel is indeed less. I lost almost 3/8" clearance. I'm not too concerned about the clearance as I am about the aesthetics. Yeah, I'm vain too.


If I had to do it again, and make my own spacers, I would incorporate the spacer ring and left spacer as a one piece spacer. I had considered boring out the 3.3mm into the left R6 mod spacer, but there wasn't enough material there to do anything, otherwise I would have.

This turned out to be a fun mod and one I think is going to work great. It can easily be done in a day if you have all the parts and tools. The difficulty level would be for the advanced intermediate, high up there in my mind but definitely not as difficult as replacing the head bearings I did at the beginning of last season.

Cheers and safe riding!

Edit: Here is the final iteration of the bracket modifications that I am currently using, but first a shot of the left leg showing the axle recessed into the leg a small amount.

View attachment 26658

The front and rear brackets have been shortend to obtain the fender to wheel space as the original FZ6 fork. This meant that the fender sits a little higher on the legs, but not so they look out of place.

View attachment 26659 View attachment 26660

Here are the dimension drawings for the modified brackets that I am using.

View attachment 26661

 

[afpreppie04]

Looks good, but is that tire on backwards in the last picture? I lost height when I swapped over too since I went to the R6 fender, still figuring some way to get space back, I'd like about 1/2" more.

 

[Kilbane83]

Beautiful craftsmanship on those fender brackets.

 

[yoshiki]

that solves most my the questions marks on my head what are those shims and spacers people are selling for. curious, what if i intend to fit the r6 inverted forks? those shims and spacers are the same ones?

 

[tuningfork]

now that you have reduced the spacer, does this put a bend into the fork tubes? I am assuming the point of all these spacers was to keep the tubes precisely aligned to the width fixed by the triple-tree? I would be concerned a bit that you have induced some sideloading on the tubes (binding, bushing/seal wear, etc.).

The short axle situation is not good either to me, that seems like it will place some stress on the lower fork leg clamp region and would allow some flex axle/wheel tilt during suspension action.

Is it not possible to use the triple-tree from the R6? Seems to me that would solve all these alignment issues?

Another thought would be to use the original kit spacers so the forks are properly aligned, then machine a ring to insert into the fork lower to fill in the gap, then source a longer axle bolt to pull it all together.

 

[afpreppie04]

that solves most my the questions marks on my head what are those shims and spacers people are selling for. curious, what if i intend to fit the r6 inverted forks? those shims and spacers are the same ones?

No, the inverted forks are a whole different ballgame. A user on here did the conversion and it was a lot more work, involving machining and welding and whatnot.

Is it not possible to use the triple-tree from the R6? Seems to me that would solve all these alignment issues?

I thought this same thing when I did the swap, but unfortunately the steering stems are different. Also since they are different widths if you swapped the stems over you would have to use the R6 upper triple with it, so you wouldn't be able to mount your handlebars.

 

[tuningfork]

good point on the handlebars! :banghead:

 

[sonic]

For the axle bolt length problem, could you have used a longer bolt? Not all of us have mini machine shops in our garage!

 

[bd43]

For the axle bolt length problem, could you have used a longer bolt?

Yeah, that would have worked but I couldn't source one that had a flange on it around here.

 

[dako81]

This is the type of feedback that I needed. Now I can make some higher quality parts. Also I can get my butt in gear and get some forks myself so I can do it too...

 

[hot4teach]

For the axle bolt length problem, could you have used a longer bolt? Not all of us have mini machine shops in our garage!

For the many, many people that have already done this swap, the axle bolt length isn't a problem. You don't need a longer bolt. If you really want to get the axle to slide more to that side, it would probably be easier and cheeper to turn the axle down where it gets bigger.

 

[alkinoos]

Very nice work you did there!
This is the kind of posts i really like to read. Detailed and simple.

By the way, i really like the small brackets you've made for the front fender.

 

[bogdani0405]

Hi,

Do you still have the FZ6 Forks and the 4 piston calipers? Do you sell them? How much would you want for them? I want to change the 2 piston calipers I have now on my FZ6 with 4 piston as I heard they break better, but for that to happen apparently I need to change the front forks too.

Thanks

 

[FinalImpact]

Hey I just wanted to thank you for these posts! They were extremely helpful and saved me a bunch of trial and error! :thumbup: :thumbup:


Just my 2 cents on the bolt and the gap between the axle end and forks outside edge: As long a bolt penetrates to a depth equal to the diameter of its cross sectional area of threads, its doing as much as it can to secure the components.

Although not desired (gap), for me its a none issue. I did apply a drop of loctite to all fasteners and greased the axle with a thin film so that if water penetrates and rust takes hold its only the loctite and torque applied fighting me to get it apart.

Oh - The bike rides so much better! This is Worth the time and effort! :rockon:

 

[LERecords]

quick question.. but what is our axle even made out of??? I work with some machinist again for work, but what type of material are we talking??

 

[dmsn]

Hello
I am also intrested in doing the R6 fork mod to my FZ6 !!!!
I have read all post about the gap issue on the R6 axle.
Is there any solution found for this problem exept the movement of the whole axle to the left ?
All you have installed R6 forks you have done the same right spacer mod or you left it as it was with the above mentioned gap ????????
Is there any other better/safer solution eg using fz6 axle ???
Thank you in advance

Just my 2 cents on the bolt and the gap between the axle end and forks outside edge: As long a bolt penetrates to a depth equal to the diameter of its cross sectional area of threads, its doing as much as it can to secure the components.

Although not desired (gap), for me its a none issue. I did apply a drop of loctite to all fasteners and greased the axle with a thin film so that if water penetrates and rust takes hold its only the loctite and torque applied fighting me to get it apart.

9mm or 5mm gap is a non issue??

Where i can find this helpfull patern in 1/1 scale in order to print it also ???
http://600riders.com/gallery/showfull.php?photo=3915

 

[FinalImpact]

Hello
I am also intrested in doing the R6 fork mod to my FZ6 !!!!
I have read all post about the gap issue on the R6 axle.
Is there any solution found for this problem exept the movement of the whole axle to the left ?
All you have installed R6 forks you have done the same right spacer mod or you left it as it was with the above mentioned gap ????????
Is there any other better/safer solution eg using fz6 axle ???
Thank you in advance


9mm or 5mm gap is a non issue??

Where i can find this helpfull patern in 1/1 scale in order to print it also ???
dp_100320_02 - FZ6-Forum Community Photo Gallery

Making the fender fit is the least of you problems. That gives a clear idea of what needs done. Its not critical its cosmetic.

As for the axle and bolt:
Look at this way - the other side has nothing. Its relying on the two pinch bolts to secure the axle in the fork. And as stated, the strength of fastener is typically obtained when the bolts thread diameter (lets says it 10mm) reaches a depth of 10 mm into the hole. Beyond that, its not doing much unless its steel into soft none heat treated aluminum or something like that.