OK, guys. $14.50 suspension upgrade for both ends.
Aluminum flat stock 2 pcs for $4.50
2 - 3/8" pipe nipples for spacers $1.50
1 jug of 5 wt. fork oil for $8.50
Total Cost: $14.50
For the rear make new, shorter, connecting arms (dog bones) out of aluminum flat stock.
1/4"T X 1.25"W X 6.625"L. Hole locations are 5.38" apart on center.
I always use a pilot drill to locate the holes, I then used a 15/32" drill to finish to size.
To install, place the bike on the center stand, unbolt factory dogs, lube suspension bearings while your there, install new bones.
The shorter dog bones raise the effective spring rate about 20%.
The fork upgrade consists of shortening the spring and using a different quantity of 5 wt. oil.
The weight of the oil does not effect the ride height or the spring rate. It affects the speed at which the oil can pass
through the valving used to do the dampening. By stiffening up the front springs the way I did, (shortening the tight
wound end, the softest part of the progressive spring), then adding to the spacer length, the ride height stays the same
but a bit more firm. Going to a thinner oil allows the oil to move more quickly through the valving, thus the suspension
is more compliant over highway stuff and can give a better feel when leaned over. The extra oil causes the air space left
in the top of the forks to become compressed under heavy braking or when coming down from a good wheelie, thus giving
an air shock effect to the front.
Here is the fork procedure in detail:
- Remove the front brakes, wheel and fender.
- Loosen the cap at the top of the forks 1 turn.
- Loosen the lower pinch bolts on both legs.
- Grab one fork and have helper loosen it's upper pinch bolt.
Warning: The fork will slide down so be ready.
- Clamp lower fork by the brake mounting ears in soft jaws in a vertical position.
At this point it is advisable to back off the preload as far as it will go.
Also back off the rebound screw as far as it will go.
This will facilitate easier removal of the cap and proper reassembly of all internals.
- Remove cap from fork tube.
- Remove the cap from the damper rod.
- Remove the rebound rod from the damper rod.
- Pull down on the spring retainer washer and the spring preload spacer and remove the nut on top of the damper rod.
- Pull off the spacer, washer and the spring.
- Place the spring in a pail to drain or wipe off the oil.
- Unclamp the fork and dump the oil in a drain pan.
- Pump the damper rod up and down a few times to purge the system. Stand upside down in the pail with the spring to drain.
If you like you can flush the fork with a little clean fork oil then drain. Do the same with the other fork.
- Wipe off spring and measure up 1" from the tight wound end of the springs and mark to cut off.
- Cut spring to length. This will stiffen the spring. The one inch shorter spring with longer spacer retains the stock ride hight.
- Heat spring across from the cut off point and use needle nose to pull the last coil to be flush with the next one.
I used mapp gas. Heat till red and bend down with pliers. The spring steel won't move until it gets red in at least a small area.
The mapp gas worked quite fast actually without undue heat. The last coil is dead anyway, so no worries.
- Then use a pedestal grinder to grind the spring flat on the end.
It should look like this.
- Grind or cut and grind a new spacer from a 3/8" pipe nipple 1" longer than the stock.
Should be 3/8" diameter X 4" then ground down to 3.602". Sounds off, but the 3/8" nipple is large enough to fit
over the damper rod and make good contact with the lock nut. The diameter is not critical, it just needs to not
slide over the dampening rod to fork cap lock nut.
- Clamp one lower fork leg in the vise as vertical as possible.
- Make a fill gauge from a piece of coat hanger and mark with tape at 4.75" to go in to the top of the fork leg.
- Fill fork to mark with new 5wt oil. Then pump the damper rod up and down a few times to charge the system and repeat
the fill and pump process until it holds. Then let stand a few minutes for air to all work out, and check fill level one more time.
- Install the spring in the tube.
- I use a small part or dropped tool grabber to pull up the damper rod from inside the spring.
- Then grab the damper rod through the spring, then slip on the spring retainer washer, the new preload spacer, and the retainer nut.
- Once the retainer nut is started you can pull down on the spacer and the spring washer to spin the nut on as far down the damper as possible.
- Then slip the rebound rod back in the damper rod assembly.
- Screw the fork cap onto the damper rod.
- Tighten the cap on to the damper rod as far as possible.
- Tighten the retainer nut to the bottom of the fork cap.
Reset the rebound damping adjusters before refitting the top cap to the fork leg. Wind the adjuster screw all the way out
anti-clockwise, then back in again 42 clicks. This ensures that you have sufficient range of adjustment available in either direction.
Once the top caps are back on the fork legs, wind the adjusters fully in (ie, max rebound damping) then back them out by the required
number of turns. This is to ensure that you haven't inadvertently altered the damping screw settings while the forks were apart.
- Have a helper pull up the fork tube so the cap can be tightened to the fork tube.
- Assemble the other fork leg the same as this one.
- Install the forks in the clamps. Set at 1/4" above the top clamp. This will allow the use of the center stand with the dog bone installed.
- Install wheel,brakes,and fender.
- Torque all assemblies as required.
RECOMMENDED DAMPER SETTINGS: a place to start.
NOTE: Compression and rebound setting should be arrived at by turning fully in then backing out the correct number of clicks.
spring preload - - two full rings showing as in the photo above.
compression - - 4 clicks out from full in.
rebound - - - 3 clicks out from full in.
Rear shock with dog bones:
spring preload - -- 6 clicks down from full or maximum.
compression - - - 7 out from full in.
rebound - - - 4 clicks out from full in.
WARNING: DO NOT FORGET TO PUMP UP THE FRONT BRAKES BEFORE YOU TEST RIDE !!!!!!!!!
OK, now go ride your new bike. You'll swear it ain't the same bike.