Fork oil change, big improvement

[Rick]

After finding the front suspension too much on the firm side I recently changed my fork oil from Putoline HPX 10 to Rock Oil SVI 10 and the ride over poor surfaces is much improved. Tested over a three day trip to Wales I have found the stock suspension and handling is now just right. The centistoke (cSt) level for the Putoline was around 50 and the cSt for the Rock Oil is 32,( the Honda10 I believe is 35.2). The Rock Oil SVI 10 is fully synthetic. It has been said before but you really need to first check the cSt tables when choosing a fork oil,  the SAE 10 figure appears to be of little use. The cSt levels given are at 40degees C .

[Art]

Yes, I've never fully understood fork oils but do know that a SAE 10W fork oil can vary between 7.5W and 12.5W at 40°C. I'm not sure what the normal operating temperature of fork oil is but it makes sense to be guided in your choice of fork oil by the centstoke (cSt) viscosity which is calculated at 40°C.

At my last fork oil change I used Yamlube (Yamaha) G10 which is 33.2 cSt, purchase decision based on local availability and price (£8 for 1L off the shelf)

Here's a couple of others I've noted as being close to the reassuringly expensive Honda 10W fork oil which is 35.2 cSt

Motul medium 10W = 36 cSt
Silkolene medium 10W = 34.9 cSt