Hyperpro fork springs on Gen II - HOW MUCH OIL?

[MCRIDER007]

Edit - The plot thickens... I just went to the Hyperpro web site and can see that their springs are not fixed rate springs. They are progressively wound springs. This explains why they want to get rid of the air spring effect. They have built in a proigressive rate into the coil spring and do not want the air springs contribution messing up their pre-defined rates.

I had the opportunity to get up close and personal with JohnnyB's Hyperpro springs at the last tech day and the springs are much thicker than what shows in the picture and the transition from the two spring rates is even more pronounced. I don't see how they can be called "progressive" since there is nothing progressive about the way they are going to perform, the tightly bound springs are going to bind just from the weight of the bike (I could bind the tightly wound springs with just the weight of my upper body) and the rider will be using the "stiff" end of the springs 100 percent of the time.....just like a GL1800 with OEM fork springs. I thought it strange that Hyperpro doesn't give any data about the actual spring rates.

They are big and bulky and are going to displace a lot of air but I doubt it is an additional 210 cc.

 

[ionbeam]

I have progressive springs on my FJR and when the preload is set the 'progressive coils' are already in a bind, leaving the springs as a short, straight rate spring with the progressive part of the spring simply a dead spacer. No more progressive springs for my FJR.

 

[Fred W]

I suppose the lighter force portion of the spring would come into play on extension of the forks, like when you unweight the front wheel over a rise, but I'm not sure how that would be a good thing.

Once the softer spring section is coil bound it would act a lot like the spacer that you install on most every other aftermarket spring. But it would be a lot harder to adjust the length of it to trim the preload.

 

[tiz]

Not sure about all these details of sprint rate and type. The end result is that the bike drives beautifully. I was able to hit the sag measurement they wanted easily. What is actually happening to the spring inside the fork tube is not my concern. That the bike rides and corners well is my concern. It does that just fine.

Still haven't checked for qt / ltr container but I'll try to remember that tonight. I could check to compare the air gaps with the forks in and bike on the jack to get the front wheel up. Just not motivated A) to take it apart again now that I'm riding it after a month off the road and B) it works fine so why bother?

--Kevin

 

[tiz]

Oil containers were 1 Liter, not quart. Someday I'll see if the oil levels are equal in the forks. Still works just fine.

--Kevin