Honda XR650R Suspension www.borynack.com  xr650r@borynack.com Bruce Borynack  http://www.borynack.com/Bruce/XR650R/xr650r.htm 

HOME   This page was written by BWB and edited by; Eric Foster [A.K.A. "The Hay Maker"] from the Pig Pen

This page was put together to help the Owner of his wild bucking Oinker, to make BRP (Big Red Pig) into a lean smooth running squealer! Some like to do the work on their Bike to make it more theirs...Others to save Money or can't afford the killer prices of suspension shops...Some for the challenge.....this is a page to help you gather more info that you might not find in your Service Manuel (On Line Service Manuel) Or can't figure out Looking at the Parts Fiche (On Line Parts Fiche)   http://www.off-road.com/dirtbike/tech/forkoil/ 

            Spring Rate Chart is at the bottom of the page! 

The first step is to get at the fork internals. Removing the forks from the bike isn't necessary, but if you feel ambitious, go right ahead. Either way, be sure the bike is supported securely. If you've never run into it, trust me, fighting with a 289lb pig with no front forks is not much fun in my book!

 If you decide to just pull the internals with the tubes attached to the bike, you may have to loosen the top clamps with a 12mm tool.  The caps are 30mm, or just under 1-1/16". If you are removing the forks to do this job, loosen the caps before removal from the clamps, it's much easier and you won't risk scratching the chrome in a vise. 

 When you remove the cap from the tube, stand a bit to one side in case spring tension sends the ratchet into orbit. Once the cap is removed from the tube, either lower the front of the bike to the ground to compress the forks, or run a tie down from the bars, down through the front wheel, and then back up to the bars. Whichever you choose, the forks need to be held in a compressed state.

 Next step is to remove the cap from the now exposed damper rod. Use a 17mm wrench as shown at left to hold the locknut while spinning off the cap. After the cap, spin off the locknut. You can either use a #2 allen to keep the damper rod from spinning, or a small set of Vise-Grips. If you use the grips, put cloth or paper towel in the jaws so you don't scratch the surface. You don't want any burrs damaging the bushing in the  Cylinder Composition (Big techy Honda word) when  you pull the damper out.

 

You’ll need tools like this.

 Remove the spring and locknut. There may or may not be a washer on top of the spring. The manual (I say again, you DO HAVE ONE, right? If not, d/l it at left) shows a washer up top. Inside the damper rod there are two pieces, the Adjuster Collar and Distance Collar. They are shown at left. 

 The collars are easily removed by quickly pushing the damper rod down into the fork tube. The oil trapped below the damper will force them up and out. Pay  attention to which way the smaller (Adjuster Collar) fits. Slotted side down.  

The next step requires a couple of special tools. One is a hollow 27mm allen head wrench, and the other is a 14mm allen. If you can manage to find all the pieces that just thread together, from your local Ace Hard Wear store, then you'll make the job allot easier. Make sure you Epoxy the fittings together and put a pin through the "T" where the handle and the shaft come together. Mine is made out of 3/4" pipe and the 27mm Hex is made out of a copper slip to 3/4" thred fitting...the slip part is cut off. Eric from the Pig-Pen welded his up from what he could find around his shop. No fret, I just happen to have the directions on how to make his here!

 Either find someplace to borrow the tools, buy them, or follow my simple directions, then precede with sproinging your boingers!  

 

 Here's where we start to get messy. If you've removed the forks, it's not bad.  If you haven't, then be prepared, keep the small children and Chihuahua away! You'll want something to catch a quart of oil under the fork legs. I also, being a neat freak, always have a few cardboard refrigerator boxes kicking around for special occasions like this. These puppies make cleanup easier, keeping all oil off the floor.

 Remove the rubber plugs from the bottoms of the forks and unscrew the compression adjusters all the way.

 Now insert your newfangled tools and unscrew the compression valve stack from the fork. Take a peek at the fiche, part #13 is threaded into #11. You'll end up with the compression stack at right. Oil everywhere!

 

 I get my shims from here:  Race Tech or here > MX-Tech.com

Brain Surgery!

 

 Clean everything up with a good supply of compressed air, brake cleaner, and lint free paper towels. This is essential; Brawny won't do for this application. If in doubt of the cleanliness before reassembling a part, get out the brake cleaner. Buy 5 cans before you even start. While you're at it, but a good set of safety glasses. First time you ricochet this vulgar fluid into your eyes, you'll see (nothing) why.

 Use a file or some other abrasive tool that you have good control over to remove the staking on the nut of the stack. Don't remove any more than you have to and don't nick the seals, washers, or valve. After you get the 12mm nut off, but before you remove the anything else, remove a little material from the circumference of the first two threads. The staking distorts them and the valve will not slide off over the bulge.

 Now remove the washers and valve. Be absolutely sure to keep everything in order! Lay them out or hang them on a piece of coat hanger, just don't mix them unless you feel you have a truly photographic memory. Don't rely on the service manual or fiche, they won't match

.

Just to show the difference in hole size. Drill out all four holes. Do not drill out the holes on the rebound valve.

 If a "plusher" ride is what you are looking for, now you have to drill the valve to mimic a "Gold Valve". To the left is the valve with the top two holes bored to; 3.64mm /.0143 of an inch. Stock the holes are 1.96mm / .0775 of an inch. That is a huge difference! 

Using a 9/64th of an inch (3.57mm) or a  #27 wire gauge bit (3.64mm) you can drill the holes out. 

 Obviously this picture is just for comparison, you want to drill all four holes. Do Not drill out the rebound valve on the long saft.

Doing this mod will require that you run a stiffer valve stack. Stock holes are 2.65mm on 2000~2004 models but, I just did a 2005 that had 1.96mm holes. The picture is of a 2003 compression valve with the top two holes drilled out and the bottom two left stock.

 

 The picture to the top right shows the stock (top) and modified (bottom) compression stacks. This is the standard "Fast Trail Rider" setup. It's plusher, yet will still handle 4' drop offs and some mild jumping. To do this, starting from the right, removed the 2nd, 3rd, and 4th (1-22mm x .10mm & 2-20mm x .10mm) shims and replaced them with two 21mm x .15 shims. All fork shims have an ID of 8mm.

 Reassemble the valve stack back onto the core in the proper order, again making sure that EVERY shim is clean. 

Install and torque the nut to 25 to 30 INCH POUNDS, this is very important. Make sure to use a small amount of Locktite and don't let it weep into the shim stack. Then stake the nut. 

 More or less will change the way the stack reacts to the oil pressure.

Stake the nut as shown to hold it from coming apart. Use a thread locker (Red locktight) and make sure you get it only on the threads on the nut or you risk it wicking into the valve stack and causing problems. Let it dry before assembly.

On the Rebound!

When working out the rebound shim stack you have to take into effect how stiff the spring you are using. Stiffer springs (.47kg/mm and higher) need a stiffer slow rebound stack. Do not drill out the holes on this valve. 

 The rebound stack is located at the end of the damper rod that was attached to the fork cap. With the compression stack removed, just pull up the rod. The rod will come out with a large aluminum piece (fork damper) and a smaller piece on the end, slightly cone shaped, called the Oil lock.

Once the assembly is out, slide the damper rod back down through the damper to expose the rebound stack. There is a Teflon bushing in the damper end, be careful not to score it with the threaded rod end.

On the rebound stack I would run (6) 21mm X .10mm, 13mm cross over shim, (2) 21mm X .15mm, (2) 20mm X .10mm, 18mm X .10mm, 16mm X .10mm, 14mm X .10mm, (I like leaving out the 12mm X .10mm shim here, I use it elsewere.) 11mm X .10mm 

Install and torque the nut to 25 to 30 INCH POUNDS, this is very important. Make sure to use a small amout of Locktite and don't let it weep into the shim stack. Then stake the nut. 

This valve setup, in combination with .45kg Eibach springs, will carry a 190lb rider with gear with true finesse.  "It's as much an art as it is a science"........ The stock setup has to much flow going through the by-pass adjustment for full bend of the shims to be reached. There is also a mid-compression stack there also that is just right if the adjustment screws are a little stiff. You get better control of rebound if more of the fluid is forced through the valve. With the lighter fluid you can push more fluid at a faster rate....closing down the by-pass let's the shims control the flow more insted of it just going through the by-pass hole.  That's why I run at 11~12 clicks out on the rebound for the forks. :thumbs:. On the Suspension page it goes in to how to setup the adjusters. The top adjuster on the Forks is to adjust the rebound. I start this at 11~12 click out (click the adjuster in, clockwise, till it just stops; then count 11 clicks out). The Compression adjuster is in the bottom of the fork under a rubber plug. I start this adjuster at 16 clicks out. Lots of trail riders might want 18 clicks out but, few need 14. These are good starting points but, every bike and rider is different.

I fill the forks with 650cc of Golden Spectro Ultra light (2.5wt) or Maxima 3wt suspension Fluid.  

 

Then add till Measured to be 105~110 mm from the top of the fork.    

Single Track & Super Plush    This is the setup for everything from Duel Sport, Desert to Single track

 Maxima 3wt light fluid  

Stops bottoming about as good as stock

Compression valve drilled out.

Serious Riding, Plusher then stock big rocks, big whoops, 4'+ drop offs, Racing

 2.5wt or 3wt fluid 

Easy to setup, Less shims needed

Compression valve drilled out.

Desert Racing, Plusher  Serious Racing  

2.5wt  or 3wt fluid

What I use

Compression valve drilled out.

Baja Racing

2.5wt  or 3wt fluid

Compression valve drilled out.  

 

Serious Racing Jumping

2.5wt  or 3wt fluid

Compression valve drilled out.  

.47kg/mm springs

Rebound

Rebound

Rebound

Rebound

Rebound

(6) .10mm X 21mm 

(5) .10mm X 21mm  

(5) .10mm X 21mm  

(5) .10mm X 21mm  

(5) .10mm X 21mm  

(1) .10mm X 13mm

(1) .10mm X 20mm (1) .10mm X 20mm (1) .10mm X 20mm (1) .10mm X 20mm
(1) .15mm X 21mm** (1) .10mm X 13mm (1) .10mm X 13mm (1) .10mm X 13mm (1) .10mm X 18mm   
(1) .10mm X 20mm

(2) .15mm X 21mm **

(2) .15mm X 21mm **

(2) .15mm X 21mm **

(1) .10mm X 13mm

(1) .10mm X 18mm

(1) .10mm X 20mm (1) .10mm X 20mm (1) .10mm X 20mm

(2) .15mm X 21mm

(1) .10mm X 16mm

(1) .10mm X 18mm

(1) .10mm X 18mm

(1) .10mm X 18mm

(1) .10mm X 20mm

(1) .10mm X 14mm

(1) .10mm X 16mm

(1) .10mm X 16mm

(1) .10mm X 16mm

(1) .10mm X 18mm 

(1) .10mm X 12mm 

(1) .10mm X 14mm

(1) .10mm X 14mm

(1) .10mm X 14mm

(1) .10mm X 16mm

(1) .10mm X 11mm

(1) .10mm X 12mm

(1) .10mm X 12mm

(1) .10mm X 12mm

(1) .10mm X 14mm

  (1) .10mm X 11mm   (1) .10mm X 11mm   (1) .10mm X 11mm  

(1) .10mm X 12mm

(1) .10mm X 11mm  
 

Compression

Compression

Compression

Compression

Compression

(2) .10mm X 22mm

(2) .10mm X 22mm

(2) .10mm X 22mm

(2) .10mm X 22mm

(1) .15mm X 22mm

(1) .10mm X 21mm

(2) .10mm X 21mm

(1) .10mm X 21mm

(1) .15mm X 21mm (1) .10mm X 22mm

(2) .10mm X 20mm

(1) .10mm X 20mm

(1) .10mm X 20mm

(1) .10mm X 20mm

(1) .15mm X 21mm

(1) .10mm X 18mm

(1) .10mm X 18mm

(1) .10mm X 21mm (1) .10mm X 21mm

(1) .10mm X 20mm

(1) .10mm X 16mm

(1) .10mm X 16mm

(1) .10mm X 20mm

(1) .10mm X 20mm

(1) .10mm X 21mm

(1) .10mm X 14mm

(1) .10mm X 14mm

(1) .10mm X 18mm

(1) .10mm X 18mm

(1) .10mm X 20mm

(1) .10mm X 11mm  

(1) .10mm X 11mm  

(1) .10mm X 16mm

(1) .10mm X 16mm

(1) .10mm X 18mm

(1) .40mm X 10mm*** (1) .40mm X 10mm***

(1) .10mm X 14mm

(1) .10mm X 14mm

(1) .10mm X 16mm

(1) .10mm X 11mm

(1) .10mm X 11mm

(1) .10mm X 14mm

    (1) .40mm X 10mm*** (1) .40mm X 10mm***

(1) .10mm X 11mm  

(1) .40mm X 10mm***

Loose the extra spacer washers at the bottom of the stack as needed to have enough threads for the nut.

** this is for .45kg/mm springs add another .15mm X 21mm for .47kg/mm springs

*** Don't have to have this. I get these from extra forks that have been wasted. They are in the compression side on the rebound valve. 

 

Stock Bike  (5wt oil)

Another Shop (5wt Fluid) RB Another Shop (2.5wt fluid) PC

 Nice for racing

Rebound

Rebound Rebound

(7) .10mm X 21mm  

(4) .10mm X 21mm (5) .10mm X 21mm

(1) .10mm X 13mm  

(1) .10mm X 16mm (1) .10mm X 16mm

(1) .10mm X 20mm

(1) .10mm X 13mm

(3) .10mm X 21mm

(1) .10mm X 18mm

(3) .10mm X 21mm

(1) .10mm X 13mm

(1) .10mm X 16mm

(1) .10mm X 18mm

(1) .10mm X 20mm

(1) .10mm X 14mm

(1) .10mm X 16mm

(1) .10mm X 18mm

(1) .10mm X 12mm

(1) .10mm X 14mm

(1) .10mm X 16mm

(1) .10mm X 11mm

(1) .10mm X 12mm

(1) .10mm X 14mm

(1) .10mm X 11mm

(1) .10mm X 12mm

(1) .10mm X 11mm

 

Compression

Compression

Compression

(4) .10mm X 22mm

(2) .10mm X 22mm

(4) .10mm X 22mm

(1) .10mm X 16mm

(2) .10mm X 20mm

(1) .10mm X 14mm

(2) .10mm X 21mm

(1) .10mm X 18mm

(3) .10mm X 20mm

(2) .10mm X 20mm

(1) .10mm X 16mm

(1) .10mm X 18mm

(1) .10mm X 18mm

(1) .10mm X 14mm

(1) .10mm X 16mm

(1) .10mm X 16mm

(1) .10mm X 11mm  

(1) .10mm X 14mm

(1) .10mm X 14mm

 

(1) .10mm X 11mm  

(1) .10mm X 11mm  

I get my shims from here:  Race Tech You can also get them here > MX-Tech.com

Compression adjustment should be close at 16 clicks out and rebound at 11~12 clicks out. Desert Race setup is a great all around setup. With compression valve drilled out and the lighter fluid this is one plush setup that resists bottoming a lot more then the stock setup. I use 110mm of fluid measurement* and less will give a plusher ride to handle the jagged rocks.

 

That's it, you're done with the compression stack! If you are a fly weight you can run stock springs, then you can button things up and call it a day. If you are in the 190lb or higher range and need to run Eibach .45 or heavier springs. You will need to add a shim in the rebound for stiffer springs. One more 21mm X .15mm for each step up in spring stiffness is close.

Cutting Stock Springs To Make them Stiffer! Click Here->Stiffer Springs

Cutting your 502~506mm (they settle) Stock fork springs to 450mm and adding a 55mm long spacer will give you in the range of .45kg~.46kg springs.

You will be surprised to find out that a lot of High $$$$ fork springs that are just one or two steps stiffer are just that and come with the spacer!

I buy my springs at Lindemann Engineering: (408)371-6151 520 McGlincey Ln. #3 Campbell, CA http://www.le-suspension.com/

They are fast and Honest about having the spring or not! I have found Some of the others are not or they rely on what the computer tells them and they don't have it.....then starts the three month wait! 

I DO NOT agree with how stiff of springs Lindemann Engineering recommends! Or how stiff Race Tech Recommends! It seems they use a computer program that is setup for the MX track and/or bikes.  XR's Only and the others are right on the money.

FORK & SHOCK SPRING RATE GRAPH / APPLICATION & RIDER WEIGHT

 

Bike

Stock
Spring
Rates

140 lbs

160 lbs

180 lbs

200 lbs

220 lbs

240 lbs

260 lbs

280 lbs

300 lbs

XR400
120mm/
85mm

.382 kg/
9.9kg

.39kg/
8.6kg

.409kg/
9.0kg

.43kg/
9.5kg

.44kg/
10.0kg

.46kg/
1.05kg

.475kg/
10.6kg

.492kg/
11.0kg

.47kg/
11.4kg

.47kg/
12.kg

XR600R
125mm/
85mm

.39kg/
9.8kg

.392kg/
9.4kg

.409kg/
9.8kg

.426kg/
10.2kg

.442kg/
10.6kg

.459kg/
11.0kg

.475kg/
11.4kg

.492kg/
11.8kg

.47kg/
12.0kg

.47kg/
12.5

XR650L
130mm/
85mm

11.0kg/
92-3.41k
95001.44

.392kg/
10.3kg

.409kg/
10.7kg

.426kg/
11.1kg

.442kg/
11.5kg

.459kg/
11.9kg

.475kg/
12.3kg

.492kg/
12.7kg

 

 

XR650R
130mm
85mm

.43kg/
9.2kg

 

.41kg/
9.2kg

.43kg/
9.5kg

.45kg/
10.0kg

.45kg/
10.5kg

.47kg/
11.0kg

.47kg/
11.5kg

.49kg/
12.0kg

.49kg/
12.5kg

Click on chart to see it better. 

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