This is the first time I've ridden in 40 degree weather and it seems to me that my bike has a bit less rebound. Granted I haven't checked the tire pressure but if oil slows down when cold, wouldn't it make sense that the oil in my forks couldn't do their job as well as when they're warm? Please factor in a great depth of ignorance as you respond. Thanks!
-Dan
The effects of low temps should go away quickly as the oil will reach temp just by the movement of the forks.
A tremendous amount of heat is created by forcing the oil through the valve orifices.
If anything, colder oil would increase damping because the oil viscosity would be a little higher
Quote from: Paegelow on October 22, 2009, 08:44:38 AM
If anything, colder oil would increase damping because the oil viscosity would be a little higher
Again, please forgive my ignorance but why the F would oil have MORE viscosity when it moves SLOWER?
-Dan
Quote from: Razzo Bolognese on October 22, 2009, 08:59:07 AM
Again, please forgive my ignorance but why the F would oil have MORE viscosity when it moves SLOWER?
-Dan
Correct. Colder temperatures mean higher viscosity, which means higher compression and rebound damping.
The cold oil is thicker, so it has more resistance when going through the valving. Think of oil as a slushy and the straw as a hole in the high speed valve in your shock. When the slushy is nice and cold drinking it through the straw is difficult. Warm it up, it becomes thin and goes though the straw easily. When your bike is parked outside in the cold the oil gets thick. Ride around a little while and the movement of the forks warms the oil and it becomes thinner.
Hope this helps.
Aha! The little 2 watt bulb is shining BRIGHT today! I'd assumed (incorrectly) that viscosity was a measure of slipperyness and I was thinking that warm oil is more slippery than cold oil. Thanks to the interwebs I now know that viscosity is a measure of THICKNESS. Of course cold oil would be more viscous than warm oil!
http://en.wikipedia.org/wiki/Viscosity (http://en.wikipedia.org/wiki/Viscosity)
Thanks guys for schooling my iggorant a$$!
-Dan