I have been drooling over inverted forks, and decided that I want them on my XJ. A search of Ebay found a good set of 02/03 R1 forks for a good price, and they are even in a rare black color! That means no need to paint them. I found a great walk-through for swapping these into a Fazer, but that isn't the same as our Seca, and didn't really offer any great help. I'll start with the overview of the parts and differences.
What you need:
I sourced everything from ebay. I had to troll a bit for some items like the front wheel and forks, but there is tons of stuff available for R1’s.
R1 Fork
These forks are about 1.5in shorter than the Seca, so you will have to deal with that somehow. A better choice would be 00/01 forks as they are 5mm longer than the 02/03's. 98/99 were the same length as the 00/01, but they improved the internals in 00. I got a good deal on the 02's, and got the color I wanted, so 5mm is a small price to pay for that.
My set came with both lower and upper triples, stem, ignition, and axle. The ignition will be swapped out for my XJ ignition so the keys match.
The fork tubes vary in diameter throughout, and so there isn't full freedom to vary the position of the triples. There is some extra room though.
R1 or R6 front wheel
I believe that wheels form both the R6 and the R1 are the same from 98-02 R6 and 98-03 R1. The YZF600 has a different wheel, so don’t buy that one. After 02/03, both bikes moved to a 5 bolts wheel/rotor, so it should be easy to tell the different wheels apart.
R1 Wheel Spacers
I am not sure if the R6 and R1 wheel spacers are different, but best to go with R1’s to be safe. Someone on one forum I found said they are different, but I can’t verify that. They are pretty cheap anyway.
R1 Axle
Probably will come with your forks or wheel, if not, you’ll have to pick it up separately.
Be sure you get an R1 bearing spacer too if your wheel doesn't come with it. I couldn't find any on ebay, but they are only $17 from my local dealer. The wheel I bought came with the bearing still in place, so the spacer was still there.
Handlebar Risers or clip-ons
You can either mount some handlebar risers to the upper triple like I do, or get some clip ons, which will lower the handlebars. R1 uses 50mm clip on’s.
XJ Steering Bearings
Since you are using the XJ stem, you need the XJ bearings as well.
Rotors
Many wheels don’t come with rotors, so you may need to buy these separately. be sure you get some rotor bolts to match. Same years as the wheel should be compatible.
When buying used rotors, you should know the stock rotor thickness (5mm for the R1), and min thickness spec (4mm for the R1), and hopefully you can find out the thickness of the used rotors before buying them (some sellers post it, others don’t). If there are pics of the rotors you are buying, look at the outer edge of the rotors, and see if you can discern any kind of visible lip. If you can see a lip, then it is likely that the rotors are worn. Look for a set that doesn't have a discernible lip. See below pics for comparison.
Good rotors, no lip
Ended up being 3.9mm thick
Worn rotors, visible lip.
Another with worn rotors
It’s kind of hard to see, but you can see a little bit of shadowing around the lip of the worn rotors. It is easier to see on larger pictures, and with ebay’s zoom feature.
Wheel Fender
You need to match the wheel fender exactly to the forks you buy. I made the mistake of buying a 98-99 front fender, and I found that the mounting holes didn't line up with the holes on the 02/03 forks, so I had to buy another one.
Strategy:
I want to maintain my ride angle and ground clearance as much as possible, so I came up with several options:
Drop Upper Triple
My favorite idea is to machine a new upper triple that will drop the tube clamp down from the stem mount by the ~1.5in. needed to retain the stock ride height and angle. The lower triple has some space to shift downward on the fork, so it will shift lower because the steering tube of the seca is longer than the R1. My plan was to machine the new triple out of a block of 7075 or similar aluminum. This is totally doable with machine shop access and some engineering training (the know-how is important because you are liable for your own death if the triple breaks and you crash - that's my disclaimer if you follow this procedure).
Stem Spacer
The easiest method is to fabricate a steering stem spacer to make the Seca stem work with the R1 upper triple. This will result in a drop of the front end though.
Stem Spacer Procedure:
I am starting with the stem spacer method simply because it is easier and cheaper, but I would like to someday actually make the new upper triple, but that likely won't happen.
Stem Swap
To start, you need to swap the XJ stem into the R1 lower triple because the R1 stem is too short. Here's a comparison:
This is actually an FZR600 Stem, but I believe they are the same as the XJ600 stem.
Both have a circlip around the bottom of the stem, embedded in the lower triple, so they MUST be pressed out from the top, as shown here:
Here is a cross section of the stem and lower triple, showing the circlip:
Both my stems came out pretty easily in my HF 12 ton press. I used a 1+3/16ths socket, which worked great, except the circlip was too big to clear the socket, so I had to expose the circlip, remove it, then continue pressing. Since the R1 stem is pressed into an aluminum lower triple, and the Seca into a steel one, the interference is different, so the R1 stem is about 30.30mm, and the XJ stem is about 30.13mm, which means the press fit is too loose. In fact, I am able to slide the XJ stem right into the R1 lower triple by hand, and only the circlip catches any interference. You MUST secure this some other way. The Fazer guys had the same problem, and they suggest using a 6mm roll pin. I think a roll pin is a good idea, but with the stem not really being a press fit, I feel like I would like a little more than just a roll pin. For now the roll pin will do, but I may put a couple more roll pins in later, just to the side of the first, but they would only go through the front half of the stem. Anyway, here’s what mine looked like right after installing:
This is a 60mm long 6mm roll pin, I bought from McMasterCarr, as well as a 6mm drill bit. All in all I got the bit and 5 roll pins for under $10. The length turned out perfect as it was able to go all the way through the other side of the stem, and leaves a decent amount to prevent interference while pounding it in. I will cut off the extra later.
Stem Spacer
The upper triple of the R1 does not fit the Seca stem either. The R1 stem is larger diameter at the top, so the hole for the stem in the upper triple is too big for the Seca stem. Also, the R1 upper is thinner than the Seca upper triple, so it needs to be thickened as well. To do all this, a spacer will need to be fabricated. To keep the ride height as high as possible, the spacer will sit on top of the upper triple, so that the upper triple is sitting flat atop the stem nuts.
The goal of the stem spacer is to make the R1 upper triple the same dimensions as the XJ triple, in order to make it fit the XJ stem the way it normally does. Here are some pics of the 2 triples and their dimensions:
R1 Upper Triple
R1 Stem hole diameter: 28mm (27.85mm on the stem)
R1 Rim diameter: 31mm
R1 bottom side shroud diameter: 44mm
R1 Overall neck thickness: 11.5mm
R1 stem hole height: 6.5mm
R1 Rim height: 2.9mm
R1 top side shroud diameter: 42.5mm
FZR triple
FZR Stem hole diameter: 23.5mm (23.4mm on the stem)
FZR Rim diameter: 26.5mm
FZR bottom side shroud diameter: None
FZR Overall neck thickness: 23m
FZR stem hole height: 19.65
FZR rim height: 2.25
FZR top side shroud diameter: ~18mm
FZR Stem Bearing surface: 24.95mm
Distance from R1 to FZR bearing surfaces: ~22mm
Spacer Fabrication
I had one of the techs at my work machine this spacer for me. It is a very easy component to machine, and should not be too expensive to get from a machine shop if you don’t have any connections. Mine is made of simple 6061 aluminum, 1.5in bar stock.
Here is the drawing:
This sits right down into the stem hole on top of the R1 Upper triple. You could make this spacer to fit underneath the triple (this is what the Fazer guys do), but that will effectively push the frame down relative to the forks. The top triple is the limiting factor on height, because you can only mount them at the very top of the forks, no higher. With the spacer below the upper triple, the frame is that much lower relative to the upper triple, but with the spacer above the triple, the frame is a high as possible. Having the spacer on top of the triple should give the highest ride height and ground clearance possible.
Height Comparison
Here is a snapshot comparison between the height of the FZR forks and the R1 forks
The R1 forks are a little bit behind the FZR forks, so they look a bit shorter than they really are. They are actually closer in height than I expected.
Ignition Mounting - Done
The stock R1 ignition is attached by security break-off bolts that must be drilled out. They may be removable by grinding a slot in the heads and using a strong straight-edge screwdriver, but the bolts are loctited in, so you would need to use a torch on the triple-side mounts to fry the loctite before trying to back them out. I drilled off the security heads and used vise-grips and my torch to get the studs out.
The ignition mounting holes are slightly different pitch between the R1 and the XJ. The XJ bolts are slightly closer together than on the R1, so the holes will have to be expanded out to fit onto the R1 triple.
Also, the height of the ignition is less on the R1, so you need a couple 12mm spacers to make the ignition sit in the right place within the ignition collar on the triple. Also, you need to cut out the gusset/web between the ignition mount points on the top triple because the XJ ignition on a larger diameter than the R1 ignition.
To update this, I ended up getting some nylon spacers from HD to fix the ignition height, which worked perfectly. I also ended up mounting the ignition by just 1 bolt rather than expanding the holes to make the ignition span both R1 holes. This has been fine for the last year, it fits tight and perfect, so I don't see a problem with it.
Gauge Mounting - Done
The Acewell mounted right on top of the handlebar risers.
Brake Hose Mounting - Done
I started to make a custom bracket, but once i got everything assembled, I don't think I really need it.
Headlight Mounting - Done
I made some custom headlight brackets that attach to the forks with some hydraulic hose clamps. See a later post for pictures.
Speedometer - Pending
The R1 wheel doesn't have a speedometer clutch, so I need to find a universal sensor to replace the clutch.
Fender - Done
Handlebar Mounting
In order to maintain the comfortable riding position I have come to appreciate in the XJ, I wanted to at least raise the handlebars back up the their normal height. I can’t avoid lowering the front and a bit, but I can raise the handlebars to compensate. After looking around quite a bit at different OEM handlebar risers, I ended up getting this set off ebay for about $20.
They seem pretty decent for the price, and raise the bar about 2 inches above the triple. The upper triple of the R1 is a bit thin, so I didn’t feel great about just drilling out some holes and mounting these on, so I made a backing plate to distribute the force a bit better.
The First Pictures
Here is the intermediate result:
I took it for a very short ride up the street (could go far since it is night and I don't have a headlight). The riding position is fine, and the forks feel very nice and smooth. The tire on there right now is old and dried out, so I need to swap it out for the one on my FZR wheel.
Some additional notes:
Another option that I read about is using a 2nd gen Fazer upper triple (2nd gen being 06 and up). It apparently has the same spacing and offset as the R1. I am not sure if the fork tube diameters are the same, but the Fazer guys said it would work, so maybe it would. I haven't researched that at all, but it might be a possibility. It uses a traditional handlebar, so you wouldn't need risers for that.