suspension oil in the cold

[Warren]

I hadn't really thought about it until the other night when I was riding home, but I have noticed that my bike seems to be riding considerably stiffer now than it does in the summer. I am sure that this because the colder suspension oil is cold and therefore raises the damping level. My question is how much does the oil warm up when you ride? I guess I don't know how much cycling the oil actually does through the dampers. Is it enough that on longer rides it will warm up and thin the oil back out? I am thinking about backing the rebound damping off a little, it just seems like the suspension is not quite quick enough.

[pilot]

Warren,

Congratulations! You are one of the few that will saunter off into the terrain of adjusting their suspension's damping visa the "clickers" on the damping settings.

At lower/colder temperatures suspension fluid is thicker and therefore flows slower.

You can check your owner's manual (but it may not have the detail needed) or you can do some internet research to see what recommended setting can be used for initial testing.

It generally takes about thirty minutes of good solid riding to get a suspension up to temperature. Attempting adjustments prior to the fluid being at normal operating temperature will lead to false readings on your buttometer (about half of all riders can get a decent feel of the forks action, but very few can really feel whether nor not the rear is in a proper performance outline). If one has access to on-board telemetry, such as the ShockClock from Race Tech, a very good assessment of the suspensions performance can be attained.

In your case, it is most likely that the suspension is feeling stiffer, harsher, on the compression side of damping in the slow speed circuit (remember, damping is velocity [fluid speed, not vehicle speed] sensitive). Your out-of-the-box suspension, on the FZ1, has adjustable compression and rebound damping. That is great news. Yamaha did a good job in providing the bike with decent suspension set-up. Check your clicker position and note it down before you start to make any adjustments. Generally, one full turn from the fully closed position is a reasonable place to start for checking the ride quality. You can easily see the effect of turning the adjustment all the way out in that the needle will have little or no effect in the orifice;hence a very plush, water bed ride can be felt--bad for turn-in ability.

Due to the slower travel of the fluid in colder climes, then there is an increased chance for "packing" to occur. In this condition, suspension fluid can not refill back to the proper sag position. As each bump is encountered the fork or shock will get lower and lower until it runs out of room to convert the encountered bump into suspension travel and a condition of bottoming may be felt. Riding straight down the road this will only feel like a harsh ride. In a turn, it will mean that the tires will loose contact with the road and that is obviously not a good thing.

Take your time to take notes of your adjustments and how they feel. You can always go back to your original settings... a place from which you are familiar. Finally, suspension setting is not an exact science and there is a lot of knowledge out there. I look forward to hearing others responding with their experience to your inquiry.

Good luck:)

[Warren]

Thanks for the info pilot. I have definitely played with the adjustment quite a bit. On a downhill mountain bike where the bike constantly hits large bumps suspension packing is really noticeable. I have a decent amount of experience tuning those dampers. Just as a note, modern mountain bike suspension has slow speed and high speed compression settings, rebound, as preload and sometimes even an adjustment for how progressive the spring rate is. I was really happy with how the suspension was set up this summer, the difference was night and day from the stock settings to where it is set now. I felt far more confident in turns and never felt like the suspension was holding me back. On the other hand now it feels different. I know it depends a great deal on ambient temperature, but I have kind of came to the conclusion that the oil will never heat up to the level that it does during the summer time. What do you guys think?

[pilot]

Perhaps the next step up in viscosity index? For a really detailed look at suspension fluid (pull out your calculator) go to Peter Verdone Designs http://www.peterverdonedesigns.com/lowspeed.htm

Unless your really hammering the suspension with lots of movement, you won't see much of an increase in fork oil temperature over ambient. The rear will heat up a bit more in the winter and a great deal more than the front during hard summer riding.

Perhaps some of the ice racers will have a POV on your questions?