USD fork conversion advice

[Pat Conlon]

Coming back to this, with the FZR front end, will it accept gold dots from a '03 R1?

Yes...
 I needed to grind a very small relief on the forks to clear the cast hose line fitting on the R-1 caliper body.
You've got to look closely to notice it.
 

Pat, do you think FZR 92 USD fork set is better than Thunder Ace big conventional fork?

There is a reason you have never seen an oem or aftermarket fork brace for USD forks.
Yes, USD's are superior to conventional forks...even the TAce beefy tostada (48mm) forks.

Just as cartridge forks are always superior to damper rod forks.

[MarioR]

Coming back to this, with the FZR front end, will it accept gold dots from a '03 R1?

Yes...
 I needed to grind a very small relief on the forks to clear the cast hose line fitting on the R-1 caliper body.
You've got to look closely to notice it.
 

Pat, do you think FZR 92 USD fork set is better than Thunder Ace big conventional fork?

There is a reason you have never seen an oem or aftermarket fork brace for USD forks.
Yes, USD's are superior to conventional forks...even the TAce beefy tostada (48mm) forks.

Just as cartridge forks are always superior to damper rod forks.

Pat,

Did some homework and you are right. I was wrong about tostadas....  They are not bad fork especially they are adjustable but cartridge is way better. Can't cheat on physics.... I have FZR 1000 92 USD full front end still on the bike so this is what I will use moving forward. What will be the best for the top clamp to use/modify in your experience?

Never to late to learn something new...

Thanks

[Pat Conlon]

I used the oem FZR top clamp with 7/8" dia. aftermarket handle bar clamps and a FZ-1 bar.

 

[Millietant]

I used a pair of 2001-2005 Yamaha FZ1 handlebar risers (need to drill the 2 holes in the FZR top clamp out an extra 2mm), with a couple of penny washers sitting in the recesses on the top of the top clamps (and under the rubber pad that goes under the risers).

A perfect mount for the FZ1 bars to get the same hand grip position as the original FJ grips.

[MarioR]

I used a pair of 2001-2005 Yamaha FZ1 handlebar risers (need to drill the 2 holes in the FZR top clamp out an extra 2mm), with a couple of penny washers sitting in the recesses on the top of the top clamps (and under the rubber pad that goes under the risers).

A perfect mount for the FZ1 bars to get the same hand grip position as the original FJ grips.

Only one issue that I have, I prefer stock handlebar mounts. Not fan of the FZ1 style. Any other options for US conversion and stock mounting? Or lags are to short to pursue this way??

[giantkiller]

I made my bars. Using the clamps off of the gixxer clip ons and made them to match the fj clip ons with risers. On my 2008 gsxr1000 front-ends.
I don't like the tube bars either.  They look like dirt bike bars to me. Lol.

[MarioR]

I made my bars. Using the clamps off of the gixxer clip ons and made them to match the fj clip ons with risers. On my 2008 gsxr1000 front-ends.
I don't like the tube bars either.  They look like dirt bike bars to me. Lol.

How they secured to the tubes? Just with one Allen bolt or there is another to the top triple?

Yes, you are right with the cross bike look.....

[giantkiller]

It's just the clamp with the one alen. They have a pin that sticks down into a hole. On the top of the triple clamp. I fabricated spacers. So I could raise them up on the extensions. For touring. And remove them when riding the curves. I don't really think the alignment is really needed.  If you  tighten the clamps they aren't going anywhere. If you're worried about it you could mount them under the triple. Like they are on the gixxer. The pins originally stuck up under the gixxer triple. I flipped them over when I fabricated mine because I wanted to slide them up on the extensions I designed for the gixxer forks. So I could sit up a little. For highway miles.

[fj1289]

Motocross bars!  The horrors!   

[MarioR]

Motocross bars!  The horrors!   

For sure not my cup of tea......

[Millietant]

Motocross bars!  The horrors!   

For sure not my cup of tea......

My 2001-2005 FZ1 bars and risers match my original FJ bars for width and can be adjusted to match for height and hand position too - they're not high and wide, like motocross bars. I found the greater range of adjustment in hand position (forward and rearward) helped me find an ultimately more comfortable riding position.

[MarioR]

Coming back to this, with the FZR front end, will it accept gold dots from a '03 R1?

Yes...
 I needed to grind a very small relief on the forks to clear the cast hose line fitting on the R-1 caliper body.
You've got to look closely to notice it.
 

Pat, do you think FZR 92 USD fork set is better than Thunder Ace big conventional fork?

Pat,

Since you are modification GURU , this is what I understand for this conversion:

1. Use 92 USD up side down forks with lower triple and custom upper or FZR modified, wheel, shaft, bushings,  fender, calipers choice you want
2. What about speedo drive?
3. Alternate option use for an example 96 YZF 750R KAYABA forks (since adjustable forks with 92 FZR lower triple and custom upper or FZR modified. What about wheel than? Shaft probably will be different..... Speedo drive?
4. FZ1 handle bar or custom tall risers mounted under upper
5. Blue dots calipers or 6 pistons caliper tokico

Correct me if I ma wrong. Thanks Pat

[Pat Conlon]

Both the FZR1000 and YZF750 front ends use a mechanical speedo drive that the FJ cable plugs into.

I switched from the FZR1000 USD's over to my current YZF750 USD's and here's what I've learned.

Stay away from the YZF750 front end, it takes too much work. You have to use the YZF lower triple, punch out the short fat YZF stem (too short too fat for the FJ steering neck) then weld up increasing the diameter of the skinner FJ steering stem to fit in the big hole in the YZF lower, then press the modified FJ stem into the YZF lower clamp.  It's very involved for little benefit .  .
 The only thing you gain with the YZF750 USD forks vs the FZR USD's are that the YZF forks have external compression adjusters...the FZR forks do not. You set compression on the FZR forks via a shim stack inside the forks.  Both forks have external rebound and preload adjusters.
 I thought the ability for easy compression adjustment was a big deal but in reality, it wasn't...
I thought I would be adjusting my fork compression more than I actually am. Perhaps on a track bike it would be true but on my street FJ once I have it set, I've left it alone. It did take me 3 tries with FZR forks to get the shim stacks exactly where I wanted (you gotta take the forks apart ) but once done, all was well.

The FZR USD swap is plug and play by comparison to the YZF.
 Get the entire FZR front end, rim, axle, spacer, speedo mech drive, forks, upper triple lower triple w/ stem and fender. It will make things easier.

[MarioR]

Both the FZR1000 and YZF750 front ends use a mechanical speedo drive that the FJ cable plugs into.

I switched from the FZR1000 USD's over to my current YZF750 USD's and here's what I've learned.

Stay away from the YZF750 front end, it takes too much work. You have to use the YZF lower triple, punch out the short fat YZF stem (too short too fat for the FJ steering neck) then weld up increasing the diameter of the skinner FJ steering stem to fit in the big hole in the YZF lower, then press the modified FJ stem into the YZF lower clamp.  It's very involved for little benefit .  .
 The only thing you gain with the YZF750 USD forks vs the FZR USD's are that the YZF forks have external compression adjusters...the FZR forks do not. You set compression on the FZR forks via a shim stack inside the forks.  Both forks have external rebound and preload adjusters.
 I thought the ability for easy compression adjustment was a big deal but in reality, it wasn't...
I thought I would be adjusting my fork compression more than I actually am. Perhaps on a track bike it would be true but on my street FJ once I have it set, I've left it alone. It did take me 3 tries with FZR forks to get the shim stacks exactly where I wanted (you gotta take the forks apart ) but once done, all was well.

The FZR USD swap is plug and play by comparison to the YZF.
 Get the entire FZR front end, rim, axle, spacer, speedo mech drive, forks, upper triple lower triple w/ stem and fender. It will make things easier.

This is exactly what I was looking for Pat. Modification for the stem, etc.. this is not an issue for me. I was wondering only if that make sense to do more work for compression adjustability and looks like for street use not so much.
Thanks Pat

[Pat Conlon]

Happy to help Mario

FYI if you go with FZR1000 front end...the stock FZR springs (.77kg/mm) are too light for our heavier FJ's.
 As we know, the springs control the suspension but the valves control the springs so with the heavier springs you should change the valves (unless you like boing boing boing pogo stick fork action)

After 2 variations, here's my final spec: 

Oil level: 110mm
Sag: 35mm
Spring: 34.7 x 340 .95kg/mm (you could go with heavier 1.0kg/mm springs) 
Race Tech Compression valve: FMGV S2045
Compression bleed #55 drill (.052in.)
Compression stack C38
Rebound stack R20
Rebound needle base setting 1 turn out
Oil 125/150 Golden Spectro cartridge oil

This should save you some work.

Cheers

Pat