<img width="210" height="153" class="floatleft" src="www.motorcycle.in.th/images/articles/Six_Steps_to_Sorting_your_Front_Forks_1.jpg" alt="" />With a stand, support the front end slightly off the ground. Remove brake calipers, mudguard and front wheel. Note distance fork tops stand proud of top yoke - you'll need this when you refit them. Undo top and bottom yokes to release forks. Check stanchions for imperfections - stone chips, dead flies, etc - clean if necessary. Check for straightness.
With a big spanner, carefully unscrew fork tops. Pour out the black sludge masquerading as fork oil, and then remove the spacer, spring and washer within. Pump the fork up and down to release the last of the old oil, then allow draining upside-down for at least half an hour. You want every dirty old drop of oil out.
Choose new internals. Most bikes have a standard spring rate of 0.7 to 0.85kg/mm. If your new springs are slightly shorter then the originals, you don't need to worry, you only need new spacers to keep the overall length identical. It is also a good to suggest heavier, 15w fork oil for better damping.
Fill with new oil, instead of adding a fixed measure, the volume of oil is more accurately measured by the "air gap" - that is, the distance between the oil level and the top of the compressed stanchion. We measure this by adding slightly more than needed, and then withdrawing the excess using a syringe fitted with an adjustable guard.
Add the new spring, old washer and new spacer (if needed). Compress, then screw the fork tops back on. Bingo- two sorted forks. Add the all-important double check everything you didâ€¦
Refit the forks in he yokes. Ensure that the forks stand proud of the top yoke the same amount as standard. Tighten both yokes up, and then refit the mudguard, wheel and brakes. You are ready to test you new front suspension..