Join Date: Jul 2015
Thanked 2 Times in 2 Posts
Problems setting front sag, 2012 675R
I finally turned my attention to setting up the suspension on my 2012 675R in anticipation of a couple of track days at Barber in November--which will be as far as I know the first time this bike has been on a track. I had previously adopted the settings recommended in the Sportsrider.com database, then switched to the "comfort" settings because I was mostly riding around town with some local highway riding--where it can be rather bumpy. (The difference by the way was staggering--as you might expect from a quality suspension like Ohlins).
But what I had never done was set up rider static sag properly. Rear sag I now have at 30mm, which is in the range I want (about 7 mm of threads showing above the locking ring on the shock). However I cannot get the front sag on the Ohlins NIX 30 forks to be less than 36-37mm even with full preload dialed in. I was trying to target 30mm but can't get there. When riding over bumps and some hard braking I am NOT using up all the travel--still have about 25mm available. From this my naive conclusion is that the fork springs are too soft--or perhaps that the oil viscosity or level is not correct. Correct me if I am wrong but I thought I read somewhere that too little oil (too much air) would manifest itself at the extreme end of the forks' travel--leading to bottoming out of the suspension. This is not happening.
Another possible clue is that the "free sag"--that is the sag from fully extended with no rider aboard--also seems to be excessive. I measured 27mm front, and 13mm rear, whereas my reference material suggested this should be 5-10mm front, and 0-5mm rear.
I realize its about time to replace the fork oil, at which time I will try to figure out if the springs are appropriate for my weight. But in the meantime could one of you more experienced riders/mechanics/suspension tuners comment on whether my thinking is in the right direction? I hate to invest in new springs only to hear from someone more experienced "don't worry mate they are all like that" or something similar.
Purchased bike used with ~8,000 miles. It had had a very easy life prior to coming to me. I weigh 160 lbs/73 kg, about 175 lbs max with gear on. I don't know this for sure but I suspect that the forks have never been out, and the original OEM spring and oil are probably all still in there. So being a fairly light weight guy, I am surprised that the OEM spring would be too weak for me. By the way after much vacillation, I did my sag set up with a full tank of gas (as well as my riding gear on--nowhere could I find any recommendation on whether to set the suspension up with a full tank, half full tank or empty tank which is surprising since this could make a 30 lbs difference to the bike's weight.
Many thanks for any advice. And my apologies if this has been discussed ad infinitum (ad nauseam?) previously.
2009 Daytona 675; 2008 Sprint ST 1050; 2007 Aprilia RSV1000R Factory