Cold weather riding- bike suspension alters

[rocketman1]

Have any other noticed that during highway riding on cold mornings ie 4 - 8deg C. that the bike suspension gets quite hard and it doesn't seem to soak up the bumps as well.
My guess is the oil viscosity is increased in the forks, due the windchill factor around the forks being near zero, making the oil firm up.
Any others notice this.

Im getting mum to knit some woolly covers for my forks ... a nice pink would be cool.

[schrodingers cat]

Possibly - also internal clearances tighter due to cold. Get an heat probe for your own entertainment and see if you can identify the temp at which the fork feel 'right'

On the shock dyno we run them to achieve something approaching operating temperature before taking the actual resistance measurements

[cowpoos]

Possibly - also internal clearances tighter due to cold. Get an heat probe for your own entertainment and see if you can identify the temp at which the fork feel 'right'

On the shock dyno we run them to achieve something approaching operating temperature before taking the actual resistance measurements

front forks run ambient air temp...or dam close to it.

Its a oil issuse...he needs to find a lighter weight for winter if he considers it a real issuse.

[dipshit]

Its a oil issuse...he needs to find a lighter weight for winter if he considers it a real issuse.

Or open up the rebound and comp circuitry a bit if your bike has the adjustability.

[Chrislost]

Have any other noticed that during highway riding on cold mornings ie 4 - 8deg C. that the bike suspension gets quite hard and it doesn't seem to soak up the bumps as well.
My guess is the oil viscosity is increased in the forks, due the windchill factor around the forks being near zero, making the oil firm up.
Any others notice this.

Im getting mum to knit some woolly covers for my forks ... a nice pink would be cool.

most probably find your tyres have lost 5 PSI due to the drop in temprature... bouncey bouncey??
Your forks might shrink .001mm, a 10deg change in fork oil temp would not make a huge difference 50 deg perhaps, but not 10!

[CookMySock]

Yeah I get the same. Quite noticeable. Maybe an oil that doesn't so readily change its' viscosity with temperature would help.

Steve

[doc]

most probably find your tyres have lost 5 PSI due to the drop in temprature... bouncey bouncey??
Your forks might shrink .001mm, a 10deg change in fork oil temp would not make a huge difference 50 deg perhaps, but not 10!

Your not taking into consideration that the tar has shrunk .013489mm per degree of frost.

[Flip]

You could try one of these multi grade fork oils. http://www.nwa.co.nz/product_detail.php?P_ID=4240

Technically these 10w20 and 15w30 behave like a 10 or 15 weight fork oil at 40 deg C and a 20 or 30 weight oil at 100 deg C ie, they act like a thin oil when cold and a thick oil when it is hot.

I also believe that my bike feels hard when it is cold, but then again mine weighs 340kg so it is big fat and soft at the hardest of times. I believe a lot of the hard feeling is the rubber in the side walls of the tires going hard in cold weather.

The only problem I see with these is the multi grade fork oils is the viscosity index additive that does this trick to oils is not particularly shear stable ie breaks down slowly with use. Which is one of the reasons motorcycle motor oil has a relatively short service life, the motor oil thins when it is used in a (high shear) gear box. You might find that these fork oils thin with use faster than mono grades.

[rocketman1]

You could try one of these multi grade fork oils. http://www.nwa.co.nz/product_detail.php?P_ID=4240

Technically these 10w20 and 15w30 behave like a 10 or 15 weight fork oil at 40 deg C and a 20 or 30 weight oil at 100 deg C ie, they act like a thin oil when cold and a thick oil when it is hot.

I also believe that my bike feels hard when it is cold, but then again mine weighs 340kg so it is big fat and soft at the hardest of times. I believe a lot of the hard feeling is the rubber in the side walls of the tires going hard in cold weather.

The only problem I see with these is the multi grade fork oils is the viscosity index additive that does this trick to oils is not particularly shear stable ie breaks down slowly with use. Which is one of the reasons motorcycle motor oil has a relatively short service life, the motor oil thins when it is used in a (high shear) gear box. You might find that these fork oils thin with use faster than mono grades.

Good point I hadn't thought about the rubber in the tyres hardening up, but I guess that added to the oil viscosity issue makes a difference.

[schrodingers cat]

Good point I hadn't thought about the rubber in the tyres hardening up, but I guess that added to the oil viscosity issue makes a difference.

A cold tyre certainly has a differing vertical stiffness to a warm tyre