Fork Upgrade

I upgraded my forks as part of a complete suspension rework also involving a rear shock upgrade. As with the rear shock, I had the forks done by Curtis Pell at California Suspension Works. I went with Racetech Gold valves and straight rate springs (1.0 kg/mm, 55.88 lb/in). Curtis also services the forks with new 5 wt. oil.

This does involve removing the stock forks, packing them up, and shipping them to Curtis' shop. Here's what I recommend about this. You should package each fork in a separate box. A box of size at least 4 1/2" x 4 1/2" x 36" will do it. Wrap up the fork in a old towel or newspapers and make sure each side is cushioned for impact. The top and bottom should also be securely cushioned. Close each box very securely. Ship each box under a separate shipping form. Do not put both boxes on the same form. Declare the value of each separate box at $500. If you declare the value to be more than that, the shipper will require that you open the box for inspection by the shipping clerk. Now, I really wish I had done that myself. My forks, which I had both placed in one larger box was lost by the shipper, delivered to the wrong address. Despite daily pleas, no bonafide attempt was made to find and retrieve the package with my forks. My laziness caused me to decline the box being opened and inspected so that I could declare the true value of the forks at $1,000 at the time of shipping. So, I scratched off the $1,000 and wrote in the limit of $500. When I filed my claim for the $1,000 I was denied and received only the amount claimed at the time of shipping. Don't make the same mistake I did! The odds of this happening again are vanishingly small and Curtis has never had any problems with lost shipments, but then he uses UPS! I didn't. To continue with my fork upgrade I purchased new forks.

I wish to thank Curtis for his professionalism during this unfortunate event, his help with purchasing new forks, his cooperation in helping me with my lost shipping claim, and for his excellent customer service in helping me with the re-installation.

At the time of this writing, the total charge for the fork service and upgrade including parts, tax and return shipping was about $650. Turnaround time will vary depending on shipping distance but you should allocate about 1-2 weeks of down time. Curtis can be reached at:

California Suspension Works
128 Ada Ave., #9
Mountain View, CA 94043
(650) 968-6144
email: sales@californiasuspensionworks.com

I had my stock forks set at near maximum preload and having tweaked all the compression and rebound damping settings, the bike felt like it could do better in predictability and inspiring confidence. I was not disappointed with the result. Now set at the softest fork preload setting, the bike delivers a level of feel that the stock forks simply could not deliver. The most noticeable difference is the way the bike more closely tracks all the undulations in the road surface where before there might have been some wallowing and jittering. The idea is to keep the tires in contact with the road surface as much of the time as possible and this upgrade accomplishes that goal. This is the result, mind you, of upgrading both the forks and the rear shock at the same time.

For my weight and intermediate riding skills and style, the forks are delivered at Curtis' recommended settings:

PRELOAD: Position 5, softest out of a total range of 5 positions. You should verify that this results in the proper amount of static sag as described in the page on the stock suspension adjustments.

COMPRESSION DAMPING: 10 clicks out from fully turned in position. The total range is 21 clicks.

REBOUND DAMPING: 13 clicks out from fully turned in position. The total range is 17 clicks.

It was further recommended that I stick with these for a while before fine tuning them.

Remove Stock Forks:

First, remove the forkbrace if one is installed. Next, follow the procedures for front wheel removal.

Next, remove the front fender.

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If the side reflectors and stock brake lines are not in the way you can remove the fender first. This also makes front wheel removal a bit easier.

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With the wheel removed, remove the forks. Loosen the two lower triple clamp Allen pinch bolts (6 mm Allen wrench) on each side. Then loosen the upper triple clamp Allen pinch bolt (also 6 mm Allen wrench) and the fork will slide down. Make sure you hold it as you loosen the upper triple clamp pinch bolt or the fork will fall out on it's own.

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Install Upgraded Forks:

When you receive your forks from Curtis you will be advised to make sure the springs did not get moved from their center position during shipping. The symptom of this is that the spring will click or squeak as it rubs against the side of the fork tube as it is compressed or decompressed. The only sound you should hear is the swoosh of the oil flowing through the valves. Using your body weight and the fork held on a carpeted surface compress the spring as much as you can and listen for any unwanted sounds. Unfortunately, the FZ1 fork does not have a self-centering mechanism.

Now, I didn't do an adequate job of verifying this because after I reassembled the bike and went on a test ride, I heard a rather pronounced clicking sound as the right fork reached the far extent of the compression stroke. Apparently you have to really apply force to the fork to compress it by hand in the same way as it will be compressed in actual use.

At this point, Curtis advised me to increase the preload all the way on that right spring and ride it to see if the spring will be forced back to the center under hard acceleration and braking. Unfortunately, this did not work so off the fork came. The options to reposition the spring are:

  1. Open the fork cap and remove the spring and try to reposition it from the top. This may or may not work as the bottom may not center and is a trial and error operation.
  2. Bang the fork against a protected surface to force the spring towards the center. This is also a trial and error operation as you can never really tell what side of the fork to bang on.

I chose option 2 as opening up the fork is difficult and is no more promising than option 1. Hold the fork by the shiny part and bang it with medium strength against a protected surface. Not too gentle and not too hard. Then retest by compressing the fork as much as you can with your body weight to see if the click or squeak has gone away. I found that I could get it to come and go depending on what side of the tube I banged on. When no audible click or squeak remains, install the fork.

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Insert the fork from the bottom through the lower triple clamp and through the upper triple clamp until the top of the outer tube is flush with the upper triple clamp.

It was recommended to me by Tony Noorda of Queensland, Australia that the fork top can be placed 5-7 mm above the level of the triple clamp and this will result in the bike turning in quicker. The assessment of success of this modification is to measure the size of the chicken strips (safety strips) on the front and rear tires and make sure that they are the same size. This may tend to decrease the straight line stability of the bike however. I asked Curtis his opinion and he advised me to become accustomed to the reworked suspension before trying this.

Then, torque down the lower and upper triple clamp bolts. The upper bolts torque to 30 Nm, 22 lb-ft. The lower clamp bolts torque to 23 Nm, 17 lb-ft.

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Next, reinstall the front wheel and torque the front axle to the spec of 72 Nm, 52 lb-ft. Do not tighten the axle pinch bolt yet.

Install the brake calipers and torque the bolts to 40 Nm, 29 lb-ft.

As recommended by the July 2004 issue of Cycle World, when reinstalling a front wheel, take this one important step that can allow the front suspension to function at least as smoothly afterward as it did before. To ensure that the fork tubes will travel smoothly in their stanchions after reassembly, butt the wheel against something solid, like a wall, and repeatedly pump the front end up and down as far and fast as you can by alternately pushing and lifting on the handlebar. This automatically aligns the tubes and stanchions for the smoothest operation. Pump the fork up and down at least six times and don’t use the front brake when doing so or the action of the calipers may prevent the legs from centering themselves.

Once you’ve completed this procedure, tighten the axle pinch bolt to its spec of 23 Nm, 17 lb-ft.

Then reinstall the front fender and forkbrace if you have one.

Appendix:

My experience with this upgrade does not stop here. After removing the clicking sound on the right fork and reassembling the bike, the clicking sound came back just by exercising the front suspension by pushing and tugging on the bars in the garage. Apparently, I did not sufficiently compress the fork during the banging and testing. My dad, who was helping me with the assembly, suggested that we loosen the lower and upper triple clamps on that right fork and rotate the shiny tube part of the fork with respect to the lower part of the fork which is held in place by the front axle. Since this was easy to do I thought why not? We gave it a shot and rotated the tube one quarter turn clockwise. After retorquing the pinch bolts, sure enough the clicking was gone. I don't know why this worked but it did and that's good enough for me. Thanks dad!

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Last Updated: 07-02-2004

Copyright © 2001-04, Patrick Glenn, All Rights Reserved.
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The information presented here reflects solely my personal experience with my motorcycle and is presented for entertainment purposes only. No information presented here is to be relied upon for issues of rider safety nor to replace the services of a qualified service technician. Any attempts to follow or duplicate any of these procedures are done so completely at your own risk. By reading the information on this site, you agree to assume complete responsibility for any and all actual or consequential damages that may arise from any information presented herein.