B6 Fork Spring Upgrade

[Red01]

NOTE: Bikepics.com seems to have dumped Chris' pics.

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Ampster
Posts: 132
(4/10/04 1:00 am)

After all the mods I've done so far (14T sprocket, HS Stage 1, 5* advance, SS brake lines, etc.), has made for a more powerful B6. It feels like a totally different bike. One side effect of those performance mods have made something painfully apparent--The front forks!

Now that the bike pulls, and stops hard with no fade, the diving effect of the front forks are MORE pronounced. I decided to upgrade the stock springs to Progressives.

*NOTE* B6 forks are non-adjustable. Makes the project easy.

After talking to Dale Walker, Reading the Progressive install instructions, and pouring over schematics of the B6 forks, here's how to do it, without removing the forks, provided of course, your fork oil is good.

1) Remove the Handlebars
 a) Carefully pry the caps off with a blade or small screw driver.
 b) Remove fasteners from clamps and the clamps themselves.
 c) Pull the handlebars and move them out of the way. Wrap if necessary to protect finishes.

2) Unload the front forks
 a) Put the bike on the center stand.
 b) Position a good jack beneath the oil pan, and keep ready.


3) Unscrew the Fork caps
 a) Jack up the bike in order to unload the forks. This prevents the spring from launching itself into the garage roof... or your face.
 b) Slowly unscrew the fork top bolt. Cover it with a rag and support it.
The cap will come off forcefully. Set it aside.

4) Remove Preload Spring spacer, Spacer seat, spring using a magnetic picker tool.
 a) The spacer can be pulled out by hand. The spacer seat is deep. Retrieve it by using the magnetic picker.

Set it aside
 b) Retrieve the spring using a magnetic picker. Bring it up SLOWLY to save the fork oil.


 c) When the spring is about 1/4 of the way up, stick a BBQ skewer in between to drain excess oil from the spring


Top: OEM Spring; Bottom: Progressive Spring



5) Make a new preload spacer.
Use 1" diameter PVC piping. Use a mitre box/mitre saw to ensure right angle cuts.



6) Install spring, preload spacer, seat
 a) Use the magnetic pick-up tool, and lower the new spring in gently.
 b) Place the seat above the spring, lay it flat.
 c) Insert the new preload spacer. Be sure it's clean.

*NOTE* According to Progressive, mechanically, it makes no difference if the tighter coils are installed up or down. They will react the same way. So, I just put the spring as they were originally installed, tight coils up.

There should be excess PVC sticking above the fork. This is normal. Mark a line on the PVC at a point that is flush to the fork's top edge. Cut and clean at this point.

*NOTE* If you want it stiffer, make the preload spacer longer. Use your weight, fully geared as a reference. I weigh ~200lbs, fully geared, so this works well for me.



7) Seal the fork
 a) Take the fork cap, put the socket/ratchet on it.
 b) Lubricate the O-ring seal with a little fork oil.
 c) Press evenly, firmly, and gently. Rotate until the threads engage. Keep turning until it stops.
 d) Torque to 23Nm



8) Repeat the process to the other fork.

9) Reinstall the handlebar.

10) You're done!

I tested my work this afternoon. Did choppy stops, slow stops, emergency stops, and several hard stops from 50, 60 mph. The dive is gone! The B6 stops level. The forks no longer bottom on hard stopping. The forks also stay firm in hard cornering.

WooHoo!
Chris "Ampster" A

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