Well, not much of an experiment really just some observations made whilst setting up my sag.
Yes, there's loads of suspension threads on here but I though it would be useful to see if you guys get similar results to me.
PLUS, some of the observations might be useful for people setting up their suspension for the first time....
Bike -
1998 R1
Standard (original I believe) suspension components with 17000 miles on them.
Tools -
Biro (pen), tape measure, notepad, centrestand, girlfriend.
And me -
An athletic, muscular 11 stone, 5'7" lump of sex.
Time Taken -
15 minutes including adjustments and further measurements.
Basically, it's so quick and simple there's no excuse for not doing it!
I wont go into technique because it has been posted before or it can be Googled or read in many bike mags.
So the front -
Uncompressed = 245mm
Bike weight = 216mm
Rider weight = 206mm
Giving Static Sag = 29mm and Rider Sag = 39mm
Recommended settings are Static Sag = 25 to 30mm and Rider Sag = 35 to 50mm
THIS SHOWS that we are in the right ball park but perhaps a fraction soft (Static Sag is at the maximum end of the range), either too little preload or too soft springs.
OK, so adjustment -
Decide to add 1 full turn of preload to the front and see what happens.
Front after adding 1 turn of preload -
Uncompressed = 241mm
Bike weight = 218mm
Rider weight = 209mm
Giving Static Sag = 23mm and Rider Sag = 32mm
Recommended settings are Static Sag = 25 to 30mm and Rider Sag = 35 to 50mm
THIS SHOWS that things are slighly too hard, both Sag measurements are lower than recommended.
One Full Turn of preload has reduced Static Sag by 6mm and reduced Rider Sag by 7mm...a surprisingly large amount !
OK, so adjustment -
Decide to reduce front preload by half-a-turn.
I didnt re-measure at this stage, figuring half a turn would bring me midway between the first and second measurements.
I intend to raise the forks thorught he yokes so will be doing all this again..just did this exercise to see how the adjustment
affects the measurement.
Anyway, the rear -
Uncompressed = 397mm
Bike weight = 391mm
Rider weight = 374mm
Giving Static Sag = 6mm and Rider Sag = 23mm
Recomended settings are Static Sag = 5 to 10mm and Rider Sag = 30 to 40mm
THIS SHOWS that things are perhaps a little too firm at the rear (too much preload or stiff springs)
NOTE - NO ADJUSTMENTS MADE YET !
Now, decided to re-measure the rear, just to be certain (note slightly different measuring point to make life easier) -
Unloaded = 442mm
Bike weight = 434mm
Rider weight = 410mm
Giving Static Sag = 8mm and Rider Sag = 32mm
Recomended settings are Static Sag = 5 to 10mm and Rider Sag = 30 to 40mm
NOTE the considerably different Rider Sag !!!!!!!!! WITHOUT making suspension adjustments.
After some headscratching I realised why - in the first measurements I sat astride the bike, legs dangling.
In the second set of measurements I put my feet on the pegs.....a huge difference it made!
So what have we learned.
1) Small changes to the front preload adjustment can make surprisingly large changes to the bikes Sag.
Dont be tempted to fiddle with the adjusters without measuring is the rule here !
2) It is VITAL to sit correctly on the bike when measuring.
Just moving your feet off the pegs can make a 10mm difference in Rider Sag.
I'll follow up with a comparison of what happens when the forks are raised, see if the change in geometry affects the measurements.
Linear Mode
