Another question, if you have time :) I've been using both a 220mm and a 240mm. I've noticed that both of them have a noticable "knock" when the piston changes direction from compression to rebound, especially on fast hits (like roots, typically). After the recent services with oil replacement (see my other comment), the shocks overall became less noisy (less squishy sounds), but this knock appears to have gotten a wee bit worse. Have you noticed anything like this? If so, do you have any ideas about how to make this noise go away? :)
According to restackor it has a lot less of an effect than I would have expected, which is why I just use like water for everything. It’s only a few percent difference and mostly at low speed, so it’s really within the noise of predicting the tune with restackor.
@@leafydialupking1 I think you're right about that. I have one 220mm and a 240mm. I had the oil in the 220mm replaced with Fox 5wt R3 (should be equivalent to 15 cSt), and a slightly thicker oil in the 240mm (about equivalent to 25 cSt). The 220mm became slightly less noisy and a bit smoother on high frequency bumps, and the 240mm became significantly less noisy and definitly smoother on high frequency bumps. High speed compression does not appear to be affected (outside of high frequency small bumps), low speed compression did increase noticably on the 240mm, but much less than I expected.
@snokefilmmedia and it makes sense that it only effects low speed when you think about how the shim valved dampers work. They’re opening a certain amount based on the pressure created by the restriction of the low speed needle valve. The amount they open is dictated by how much flow it takes the make the spring force of the shims equal the force created by the pressure differential. So the higher weight oil really should only have an effect before the shim stack starts to open and the again once the shim stack can’t open further and you start to hit choke flow. This is ignoring any potential effects the viscosity could have on the port walls and on parts of the damper it has to flow through that aren’t part of the valving, like the port to the reservoir or the outer tube in a twin tube damper.
Another question, if you have time :) I've been using both a 220mm and a 240mm. I've noticed that both of them have a noticable "knock" when the piston changes direction from compression to rebound, especially on fast hits (like roots, typically). After the recent services with oil replacement (see my other comment), the shocks overall became less noisy (less squishy sounds), but this knock appears to have gotten a wee bit worse. Have you noticed anything like this? If so, do you have any ideas about how to make this noise go away? :)
Mine only made that knock when the piston was about to be fully unscrewed.
With regards to revalve -- what would happen if you just used a slightly thicker oil, such as Fox 5wt R3?
According to restackor it has a lot less of an effect than I would have expected, which is why I just use like water for everything. It’s only a few percent difference and mostly at low speed, so it’s really within the noise of predicting the tune with restackor.
@@leafydialupking1 I think you're right about that. I have one 220mm and a 240mm. I had the oil in the 220mm replaced with Fox 5wt R3 (should be equivalent to 15 cSt), and a slightly thicker oil in the 240mm (about equivalent to 25 cSt). The 220mm became slightly less noisy and a bit smoother on high frequency bumps, and the 240mm became significantly less noisy and definitly smoother on high frequency bumps. High speed compression does not appear to be affected (outside of high frequency small bumps), low speed compression did increase noticably on the 240mm, but much less than I expected.
@snokefilmmedia and it makes sense that it only effects low speed when you think about how the shim valved dampers work. They’re opening a certain amount based on the pressure created by the restriction of the low speed needle valve. The amount they open is dictated by how much flow it takes the make the spring force of the shims equal the force created by the pressure differential. So the higher weight oil really should only have an effect before the shim stack starts to open and the again once the shim stack can’t open further and you start to hit choke flow. This is ignoring any potential effects the viscosity could have on the port walls and on parts of the damper it has to flow through that aren’t part of the valving, like the port to the reservoir or the outer tube in a twin tube damper.