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|All About Brakes & Suspension Everything from the best brake pads to use, installing new brake lines,
swing arm swaps, adjusting your suspension or rebuilding your forks.
Everything you need to know on those topics and so much more is here.
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|10-31-2008, 01:06 AM||#1|
How To: Install Race Tech Emulators & Rebuild Forks
Note: GregS has installed the emulators on damper rod forks while still retaining the rebound adjustment mechanism on a different vehicle. However, this procedure follows Race Tech's installation. I did buy a used set of Katana forks, so if I want to revert them, I can.
PM GregS if you want his info or he may pop up here.
How To Install Race Tech Emulators
& Rebuild Forks On A 2001 Suzuki Katana 750
Note: this article is written step-by-step in such a way that a novice could follow. For those more familiar with forks, some of it maybe over simplified.
Note: page 2 contains info on after installation adjustment to the Emulators.
Race Tech emulators: FEGV S4101 (sold in pairs)
Race Tech Fork Springs: FRSP S353490 (sold in pairs)
Note: The last two digits represent the spring rate, these are .90 kg/mm
Race Tech Inner Bushings: FMBI 41201 P (sold in pairs)
Race Tech Outer Bushings: FMBI 41152 P (sold in pairs)
OEM Oil Seals: 51153-08D00 (2 needed)
OEM Dust Seal: 51571-41D50 (2 needed)
OEM Brass Crush Washer: 51148-36011 (2 needed)
OEM Fork Cap O-ring: 51117-12C00 (2 needed)
1030mL of your choice fork oil (Suzuki spec is 513mL per fork) (Race Tech recommends 15W @ 4" down)
Propane torch or equivalent
Brazing rod (I used aluminum - 700F melting point)
2"x2' ABS pipe & cap ($5.00 homemade seal driver)
5/16" drill bit
3mm Allen wrench or socket (for fender)
4mm Allen wrench or socket (for fender)
6mm Allen wrench or socket (for upper triple tree)
6mm extra long Allen socket (for fork damper rod bolt) (fixed typo)
10mm socket (for axle pinch bolt)
12mm socket & 6" extension (for lower triple tree)
14mm socket (for brake calipers)
17mm socket (for front axle)
19mm socket (for front axle)
24mm wrench (for fork cap)
Thread locker (Suzuki spec "1342")
Front wheel stand, floor jack or a lot of weight on the rear wheel to suspend the front end.
Plenty of rags
Rotary tool with grinding wheel (i.e. Dremel tool)
Brake parts cleaner or carburetor cleaner
Fork oil level gauge
Chop Saw with combo blade and cut off wheel
Note: The Race Tech emulators requires brazing shut several holes in the damping rod. If you are unfamiliar or uncomfortable doing so, do not attempt to install the emulators.
Step 1: Remove The Front End
The first step is to remove the side body panels (fairings), brakes, wheel, fender, then forks. To remove the fender you'll need a 3mm Allen, 4mm Allen. To remove the forks you'll need a 6mm Allen, 10mm socket, 12mm socket, 14mm socket, 17mm socket, 19mm socket and lastly 24mm wrench or socket.
The consensus is not to allow the brake calipers to hang by it's own hoses, so I used metal coat hangers to suspend them.
Before you completely loosen the forks, loosen the bolt for the top triple tree first to allow the loosening of the top fork cap. Then you can remove the forks. If you do not loosen the top fork cap, it will be very difficult to remove it when the forks are off the bike.
Step 2: Disasembly Of The Forks
Before disassembling the fork, use an extra long 6mm Allen socket to remove the very bottom damping rod bolt. I read that wrapping on it a couple times with a hammer will shock the threads and whatever thread locker it has on it. It worked without needing an impact wrench.
Note: oil will drain out of this hole.
Remove the top fork cap, along with the attached rod that controls the rebound settings, with the 24mm wrench.
Carefully turn the fork upside down to drain the oil in the proper receptacle. In doing so, the preload spacer, washer, spring, damper rod and top out spring will slide out. Pump the fork to remove as much of the oil as possible.
Use a small flat blade screwdriver to pry up the old dust
Note: save this dust seal to be used when installing the new dust seal.
Use the same screwdriver to pry out the oil seal retaining ring and set aside to be reused.
After removal of above items, hold in one hand the stanchion (shiny male slider) and in the other hand the lower fork (where the brake caliper is bolted to it) and firmly force them apart like a sliding hammer. It will take several tries to separate them but it will come apart.
Note: you MUST remove the bottom damper rod bolt before seperating the two halves.
Remove the oil seal.
Note: save this oil seal to be used when installing the new oil seal.
Remove the oil seal metal ring and set aside. (scroll down to 17th pic to see them)
Remove & discard the inner & outer bushing. (scroll down 16th & 17th pics to see them)
Once all the components are separated, I used parts cleaner to clean and remove all residue of the old oil.
So, what does 64,000 mile (103,000km) oil looks like...yuck. It smelled nasty too.
Step 3: Brazing The Damping Rod
Prep the damping rod by first removing the mesh cover with a flat blade screwdriver.
Remove the spring retaining ring.
Once these two items are removed you can use the top fork cap with the attached rebound rod to push out the adjustable rebound mechanism by inserting it in the tapered bottom of the damping rod.
Remove the outer ring from the damping rod.
Mount the damping rod into a vice and use a torch to braze the holes closed that have been opened up from removing the rebound mechanism. Determine which one of the four rebound settings you want to use, then braze shut the remaining rebound holes as well. There are three holes to control the rebound settings, the fourth setting (click) is a no hole setting.
I used a damp rag to wipe the excess braze from the surface of the damping rod after filling the hole.
Drill out the original existing compression hole to 5/16" (8mm) diameter. Then add two more sets of 5/16" (8mm) holes spaced 7/16" (10mm) apart perpendicular to each other so as not to weaken the rod. Refer to Race Tech's installation sheet.
You'll need a total of 6 holes in the lower damping rod. I used a center punch to start the hole.
Note: start from the original bottom compression hole and drill new holes going upwards.
I made the mistake of using the original hole as the center hole and drilled one above and one below it. That caused the lower hole to be completely enclosed when it seats into the "oil lock piece" as Suzuki calls it.
After drilling the holes, use a rotary tool and grinding stone to grind smooth the metal both inside and out.
After drilling, filing and brazing, reinstall the outer ring onto the rod.
Step 4: Reassemble The Fork
Reassemble the fork in the reverse order.
The damping rod and top out spring needs to be inserted into the stanchion first, then slide the "oil lock piece" onto the end of the damping rod.
Install the inner bushing by slightly separating it at the joint and slipping it onto the bottom of the stanchion.
Slide the stanchion into the bottom fork. Be very careful not to scar the outside grayish bushing. This is what slides against the fork.
After applying thread locker, torque the damper rod bolt, with a new crush washer, to 20Nm (14.5 ft-lb). If the damper rod spins as you tighten the bolt, slide a broom into the stanchion and press the broom onto the damper rod as you torque the bolt.
If you question the use of a new washer, here's a pic of the old verses the new. You'll clearly see how much the old washer is crushed.
Slide the outer bushing (again, follow the precaution above), the oil seal retainer ring and the oil seal onto the stanchion in that order.
Make sure to install the oil seal with the lettering facing outwards.
edit: Using a seal driver of your choice, seat the the bushing and new oil seal into place.
If you choose to use the homemade seal driver, slide on the old oil seal and hammer the seal driver until the new seal is seated by using a rubber mallet. By using the old oil seal to pound against, it will protect the new seal from damaged that may occur during installation.
I fabricated a homemade seal driver with a 2"x2' ABS pipe and cap. It cost me all of $5.00 and it worked great. What is required, though, is that you cut slots, like fingers, into it so that it can compress onto the stanchion by using your hand or zip ties. I used my 10" chop saw to cut the slots in the ABS pipe and cut it down to length. The fork stanchion's outer diameter is about 1.5". A 1.5" ABS pipe has too small of an inside diameter to slide over the stanchion, therefore, the use of a 2" pipe with slots.
After seating the oil seal and bushing, slide on the dust seal and install it in the same manner as the oil seal by using the old dust seal to hammer against via the seal driver.
In the emulator package there will be a snap ring that needs to be installed onto the emulator. That ring only functions as a spacer, so the emulator seats evenly on the damper rod.
The spring washer that comes in the Race Tech spring kit is slightly too large to fit inside the fork. I used a vice to hold it and used my rotary tool with a grinding wheel to grind down the excess.
The long rod that is connected to the fork cap, that controls the rebound mechanism, needs to be cut off about an inch from the end of the fork cap. It's exact length is not critical. Refer to the Race Tech installation sheet.
Next slide the emulator inside the fork, making sure it is seated squarely. Slide the fork spring into place. The fork spring will sit on top of the emulator without a washer. Slide the original spacer washer on top of the spring. Next extend the fork stanchion completely up, then measure the length with the emulator, fork spring, washer in place. Measure from the washer to the top of the fork where the fork cap will seat to the fork. Refer to the Race Tech's installation sheet. Write that number down or mark the tape measure.
Next measure the fork cap with Race Tech's washer pressed against the cap. Refer to the Race Tech's installation sheet. Write down the number or mark the tape measure.
Note: Race Tech states that you MUST use a washer at both ends of the preload spacer! Do NOT allow the preload spacer to rest against the spring or fork cap!
By subtracting the fork cap measurement from the first measurement, that length would be if zero preload was on the spring. Race Tech recommends, for street use, to have 20mm or 0.80" of preload on the spring. They also state in the instructions that "there is no magic preload number". If you want more, so be it. If you want less, so be it.
I went with their recommendations and added 0.80" onto the zero preload measurement. The final measurement to cut the preload spacer, for me, was 7-1/8". I used my chop saw with a cut-off wheel to cut the two spacers.
Next, remove preload spacer washer, spring and emulator. Pour into the stanchion 513mL of the fork oil of your choice. Race Tech recommends 15W. Pump the fork several times to remove air trapped inside the fork. When pumping it will be easy to collapse the fork, yet difficult to extend the fork. This is the compression holes and rebound setting in use.
After removing all the air, collapse the fork, measure on fork oil level gauge rod 4", then seat the ring onto the top of the stanchion and if there is excess oil, suck out the oil. If there is not enough oil, add some, then use the gauge to measure 4" of air space with the fork collapsed.
Next, extend the fork, then reinstall the emulator, spring, original washer, preload spacer, Race Tech's washer and the top fork cap along with a new O-ring. It will be a little difficult to screw on the fork cap. I set the fork onto a rigid box as well as into the vice to hold it steady and pressed down firmly to screw the cap on. Once you get it started, you can use the 24mm wrench to finish tightening the cap. You will not be able to fully tighten it yet until it is in the triple tree.
One down, one to go.
The other fork will be easier since you now know what to do.
When both forks are done, reinstall them, the wheel (make sure to orient the wheel correctly, observe the arrow on wheel) and the fender on the bike.
When re-installing the forks, Suzuki basically says to level the forks to the top triple or the clip-ons or to the handle bar bracket. In other words level the forks the way they were before you removed them. So take note of how they are before you remove them. Also, you do NOT want one fork to be higher then the other. You will have alignment and/or steering issues if you do.
Then torque the 6 bolts for the triple clamp. Before you torque the axle nut, compress the forks several times to allow the wheel to align itself. I needed to install the calipers first so I could use the front brakes to prevent the bike from rolling off the center stand. Torque the axle nut, then re-install the cotter pin or equivalent, then torque the fender bolts. Then torque the axle pinch bolt.
The torque settings are as follows from top to bottom:
Fork Cap...................23Nm (16.5 ft-lb)
Top Triple Tree..........23Nm (16.5 ft-lb)
Lower Triple Tree.......23Nm (16.5ft-lb)
Brake Caliper Bolts....39Nm (28 ft-lb)
Axle Nut...................44Nm (32 ft-lb)
Axle Pinch Bolt..........23Nm (16.5 ft-lb)
After installation comments:
Having never torn apart motorcycle forks before, I'm suprised how easy it was for me. I sure that the simple damper rod type forks also played a part too.
Even though I have never brazed before, I have some experience welding and soldering. After this install, I equate brazing with soldering but on a large scale. The same way with soldering, in that you let the wire melt the solder, you heat the damper rod to the point of melting the brazing rod. I mistakenly thought the damping rod was aluminum, hence why I bought an aluminum brazing rod. There are regular ferrous metal brazing rods, but their melting point is 1200+F and all I had was a regular propane torch. Time will tell how well the aluminum rod to ferrous damper rod will hold.
Since I can't compare newly rebuilt forks with and without the emulators all I can say is how wonderful these forks feel now. The forks feel better then the Ohlins I bought from Cyber awhile back and installed a couple weeks ago. That means that I need to dial in the shock properly. When I first bought the shock, I was so giddy, I had to turn all the nobs on it, therefore, completely throwing it out of whack. I put all the settings in the middle before I installed it, but still.
But...I'm also surprised how much the forks still dive even with the fairly stiff 0.90kg/mm spring rate. I will probably buy the 1.0kg/mm spring to see what that does. I know that I can adjust the compression by removing the emulators and stiffen the high speed circuit, but I like the setting as it is at now.
I'm getting a clicking/tapping sound and feel it in the forks under heavy compression. I suspect that it is from the Natilus Stebel horn I mounted in between the forks, on top of the fender, when it comes in contact the the front brake line T splitter. That is something I was going to eliminate anyways.
Last edited by squiggy; 06-04-2010 at 04:12 PM.. Reason: splelling :)
|10-31-2008, 02:16 AM||#2|
wow, that's a GREAT write up. I've done this 100's of times, but I can't teach someone how to do it, I lack that quality, I just do it, it's easier for me, GREAT JOB
6mm extra long socket (for fork damper rod bolt)
that's an extra long 6mm ALLEN socket
A dealer of rebuilt Katana carbs.
Partly Chris's Motorcycles
A rebuilt set of carburetors will cost more than $5 dollars
Last edited by arsenic; 10-31-2008 at 02:25 AM..
|10-31-2008, 08:23 AM||#3|
power wheelie extrordinaireSupporting Member
The only issue I noticed in the entire thing is....you never measure starting with the 0" (cap) of a tape measure when trying to measure accurately. Start at the 1" mark.
I have no clue just how accurate the measurements need to be, so maybe it does not matter in this case.
|10-31-2008, 09:09 AM||#4|
Makes Girly Parts Happy
Join Date: Jun 2008
Location: Spud Capital of the USA
Excellent writeup, Did you go on Racetech's site for the valving required for that emulator? I am going to do this myself as time and money permit.
06 750 California model Ignition coil wiring image
1988-1997-GSX600-750-1100F-R Service Manual
06 750 California model Fuel Tank hose image
06 750 California model Carb jetting image
06 750 Carb Jet Needle Identification
98~06 Katana 750 Factory Pro Jet Kit
98~02 Katana Service Manual
Cam Data Information
|10-31-2008, 10:03 AM||#5|
I have noticed some errors even after proof reading it several times before I posted it. I'll make adjustments as I see them or when people point them out.
In two of the pics I labled the bushings as both outter bushings. This is wrong. I'll change that after work.
Last edited by squiggy; 10-31-2008 at 09:01 PM.. Reason: spelling
|10-31-2008, 10:51 AM||#6|
Makes Girly Parts Happy
Join Date: Jun 2008
Location: Spud Capital of the USA
How did you valve it without knowing what it is supposed to be?
|10-31-2008, 08:04 PM||#7|
Race Tech emulators are set to a default setting of 64 lb/in, which is 2 turns of the screw. This is for street use.
|11-08-2008, 12:23 AM||#8|
Another after installation comment:
Several months ago I had the dealer replace my stearing head bearings. Since then when I slow to a stop, the bike would favor leaning to the right side.
Now that I did the forks, I don't have that issue anymore.
I suspect it was a result of the forks not properly install in the triple.
|11-08-2008, 06:37 PM||#9|
Join Date: Apr 2007
Location: California, US
I must say it's an excellent and detailed write up.
The Yamaha FJ group I subscribed to, when I had one of those beasts, turned me onto the mod which leaves the rebound adjustment intact. Basically you can remove the stamped steel "cap" on the rebound adjuster and leave the actual adjuster in place. The RaceTech emulator will sit on top of this setup with just a little grinding off the adjuster nut.
If you do an online search for "FJ emulator mod" or something like that you can find a lot of info to do it. If you want the info I've saved just email me.
|11-08-2008, 07:25 PM||#10|
One thing I wasn't sure of is how much to adjust the emulators since the rebound system would cause a restriction of the fork oil. I suppose one could some R&D to it.
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