Raising the forks on a 2006 Yamaha FZ1
I have been wanting to adjust my suspension for a while now but haven’t made the time. Well, this week the wife and kid were out of town so I had some extra time. I did a fair amount of reading. My primary resource was a page on moto-racing.co.uk.
That article walks through the setting up of suspension and what the various settings mean (ie. Preload, Rebound, Compression, Damping…) and also gives some suggested measurements.
The other thing that caused me to adjust my suspension now is the feeling that I was fighting with my bike, see previous post. I wasn’t fully pleased with how the bike was handling but being somewhat inexperienced with sport bikes I needed to do some research first. I had heard of raising the forks to change the geometry and wanted to give it a try. This article made it seem so easy, and you know what it was.
I used my digital gauge and measured the starting point of my forks. You will notice from the pictures that they were not even. My right and left forks were at .8mm and 1.35mm respectively. Perhaps not that big of a deal but when changing the forks by as little as a few millimeters, 0.55mm seems like a lot. In the end I raised the forks an average of 4.4mm to end up with a height of roughly 5.5mm
I am amazed at how much difference 4.5mm makes. The turn ins are so much lighter. I may end up lowering the forks 1 to 1.5mm if I don’t get used to it in the next month or so. It is a lot easier to turn. Evasive actions, ie. avoiding pot holes, are much less work now. I feel that I have lost a little bit of stability in the turns but that may be partially due to my learning curve with the newly lowered front end.
Further suspension adjustment:
My bike would tend to skip a bit when going over bumps, especially when accelerating. After reading the first article I linked to I decided to reduce the rear shock damping. (see chart for specific settings) This helped tremendously. My rear tire doesn’t seem to skip and hop anymore when going over bumps.
On the front forks I have only adjusted the preload. I need to study more about recognizing the affects of Rebound and Compression damping before I start playing around with those too much. I performed the “zip-tie” test, as I am calling it, and found myself, after several adjustments cycles, adjusting the preload all the way out. I am now at minimum preload and I still have too much room according to the zip-tie test. I guess this means I need to ride harder. If only there weren’t so many other vehicles in my way. This may also change slightly with subsequent Compression and Rebound adjustments.
For those of you looking for a frame of reference for setting your own suspension, I am 5’9″+ and I weight about 185lbs with all my leathers and helmet on. I ride relatively moderate to moderately-aggressive (I do live in Boston after all) and I do mostly urban and back roads riding.
Don’t be afraid of adjusting your suspension. It could be just the thing that makes riding that much better.
Thanks for reading and happy riding.