Progressive fork springs

[farm1810]

I have a 2008 RSTD and I am looking to put the progressive fork springs on it. Looking at an exploded view on a parts site it appears that I remove the top cap (along with handlebars, etc) and the springs will slide out the top without much hastle. I am going to change the fork oil at the same time so will have the bottom bolt out. Is there a reason to do a full disassembly on this just to change springs and oil?

[Condor]

I've never done a 2ndGen, but do have experience installing Progressives in a 1st. From what I understand there isn't an oil drain screw on a 2nd like a 1st. However you might be able to suck the oil out of the fork with one of those small drain pumps?? Harbor Freight?? I thought I wrote up a tech article on the job??, but can't find it right now. Basically it's removing anything in the way of unscrewing the top caps, and bend a piece of coat hanger to hook the OEM springs and preloads. Refill with fork oil to about 5 inches from the top with the springs installed. Wouldn't think you'd have to take anything else apart in the fork.

 

Found it....

[tankerman]

While it is possible to drain the oil with the forks mounted it is much easier with them off the bike. You will never get all the gunk out of the bottom of the fork unless you turn it upside down and as long as your in there it is a good idea to change the fork seals and inspect for wear. One thing I don't understand is mounting progressive springs, since these are air forks the air is naturally progressive.

[farm1810]

Great point about the air forks. Are progressives a wasted investment on a Gen 2?

[Condor]

Great point about the air forks. Are progressives a wasted investment on a Gen 2?

 

I didn't find progressives a wasted effort. Much better handling. The thought that air assist makes the fork springs progressive might be a bit off. With progressives the compression of the spring starts immediately and increases exponentially, while the OEM's spring compression is linear with the air having it's greatest effect and acting as a buffer right before bottoming out. 7 psi is next to nothing. On my '83... 17psi... I retained the air assist with the progressives. A lot of riders go without. Here's a thought. Why do OEM springs loose their strength, or wear out over time, if air assist is a major part of fork suspension??

[Great White]

Thing is, the air is an assist. Air also has odd behaviors when used as a "spring".

 

There are vehicles that use air ride only, but they are designed that way. The venture isn't designed that way, its only an assist.

 

The weight bearing assembly is the spring, you will always get better results improving the primary weight carrying device as opposed to the augmentation.

[farm1810]

Thank you. I will keep you posted. I have the springs and oil. I have the back end apart right now mounting a rear tire and lubricating suspension pieces. It will be a few weeks before the front spring change. While I'm at it, I have a Dyno 3000 that I am going to try. I'm reading on there about settings folks have tried. We'll see. I have the V-Max gears in it so a few extra RPM will be helpful. That said, I have only hit the rev - limiter once ever. I'm not exactly a speedster anymore (58 years old).