I have a few proflexs, 2 to ride and others for parts and have a vector 2, vector AL, grivin crosslink and a nolleen crosslink.
These forks are very stiff and stiffer than any other fork from the 90's that I have ridden and stiffer than some modern forks with TA's. (I am 6'4, 240lb and they feel rock solid to me especially the crosslinks)
Because of this stiffness they track extremely well. And due to their "j" shaped axle path they are extremely sensitive. This along with the minimal stiction from the small shock makes them very plush. They definitely have a different ride then telescopic forks.
One thing to note is the j shaped axle path might feel a little weird at first since the axle actually moves back a little as it moves up. Great for flat and uphill terrain, not so great for steep DH terrain.
Vector 1:
-stem is part of the fork
-top and bottom links are not unified so adjustment of both will be required if the wheel comes out of alignment.
-You can adjust the axle path by turning the upper axle rod. You can make it more of a "j" path or more vertical and inbetween. The j path is very sensitive and great for small or medium bumps and flat or uphill terrain. More vertical path is best for larger bumps and going down hill and stiffens up the suspension kind of like a low speed compression adjustment.
Vector 2:
-stem is part of the fork
-more travel
-top link is unified but bottom link is not so if the wheel comes out of alighnment the bottom link will need to be adjusted.
-you an adjust the axle path same as the vector 1
Vector AL:
-same as vector 2 with more travel but you can run whatever stem you want.
Girvin crosslink and noleen crosslink:
-more travel
-you can run whatever stem
-top and bottom link are both unified
-as far as I can tell you cannot adjust the axle path
You can get custom tuned shocks made for these forks from links below.
http://www.risseracing.com/proflex.shtml
https://www.j6shocks.com/mountain-bike-shocks.html
I have elastomers on my vector2, a noleen nr2 on my vector AL, a noleen Nr1 on my girvin crosslink and a modified fox float coil on my nolleen crosslink. The noleen nr1 and nr2 are great. The nr2 has preload (along with the nr1) and has a rebound adjustment. That with the ability to change the axle path on the vector 2 gives it some fun on the trail adjustments
There is a big difference in the forks performance when you adjust the axle path.
For fails, there was a recall on early carbon fiber girvin forks, some sort of recal on the vectors if you crashed it. Also my neighbor broke the upper axle rod on his vector 2 back in the late 90's on his 855. He said he was going pretty fast and It caused him to crash hard. He still has the bike and broken fork hanging in his garage. However, we live in Tahoe and the terrain is what you would call "chunky." He was on what is considered today to be a black diamond singletrack. These are cross country forks and I don't think suited for big chunk and rock gardens. I do think the crosslinks with the unified upper and lower links makes the fork stonger and stiffer and the upper axle rod would not break because of this, not sure.
As for maintanence, that iriders web site is full of all kinds of good info and manuals on the forks. I also have been able to find rebuild kits, seals, bushings and other parts for the forks on eBay.
Good luck with getting a fork! They are very fun to tinker with and a blast to ride.
