Progressive Springs for Front Shocks - Anyone running?

As I'm putting my bike back together, I'm always looking at little upgrades to the individual components as I go. Tapered bearings vs. ball, ATC fusebox vs. stock. Anyone running the progressive front springs and notice a difference over the stock ones? It's not a cheap upgrade but if there are benefits/opinions I'm interested in hearing them while I have the shocks torn down. The rears are an easy swap so I can run the stock and change later if there is a concern.

 

video test

 

I believe that the Yamaha OEM springs are a progressive-style design (although not manufactured by Progressive). Didn't care for the feel of the 33 year old springs..
I'm a big guy, and in the last 6 month's have replaced the front springs in two of my bikes with straight-rate (Race-Tech .95) springs. Also put new Hagon's on the rear of the 900.
Between the new bushings/seals and springs, it handles and brakes far, far better than it had. Haven't ridden the FJ since starting work on it, but am also replacing both front and rear.
Personally, I didn't want the soft initial phase of a progressive style spring, opting for a some-what longer length of even cushion (as the front wheel moves up and down).
Depending on the amount of preload used (air pressure + the length of solid stack between the spring and fork cap), seems to me that the front end can use up a fair amount of the softer dampening portion of progressive springs when the machine is fully weight-bearing the rider.
Definitely notice a firmer ride, haven't noticed any "bottom" or "top" out on big bumps/unexpected potholes or aggressive braking situations.

 

Most original springs on this era bike were DUAL-RATE springs (rather than progressive rate springs). In a nutshell, what this means is:

Original coil springs are what are known as "dual rate springs"........they have one fixed spring rate until a certain level of compression is reached, and then a firmer, stiffer rate (stronger resistance to compression) takes over (soft, soft, soft, soft, boom! stiff, stiff, stiff.......).

Replacement springs are what are known as a "progressive rate springs".........meaning that as the load on them increases, they get progressively firmer (softest, softest, soft, less soft, firm, firmer, firmer, really firm), rather than the "all or nothing" transition that takes places with the stock springs. Progressive rate springs tends to give both a smoother, less harsh ride, as well as increasing the performance of the front suspension during enthusiastic driving and the suspension action that it creates.

 

Not a ton of arguments for the progressive style springs. That vid doesn't help much, he should've done more tests with various weights to show a better curve but then again it doesn't really tell us anything we don't know.

I'm going to rebuild with the stock springs and see how they ride. I've never ridden a stock XJ, it may be adequate.

 

I put them on my 550 max. I've only been able to go on a few rides with the new spring but I'll tell you leaving the driveway going into the street I could immediately tell the difference. I also got the tapered bearing. With new tires and the progressive springs it's like riding a totally different bike.

 

I've had them in the bike for going on two decades now - they're definitely an improvement over stock.
The tapered roller bearings are a big one too - that made a huge difference in the front end.

 

While it definitely sounds like good upgrade, I'm going to stick with stock. I've never ridden a stock bike so I'll give that a try first. Well I have ridden a 650 Maxim one time, but it was around the block once 13 years ago so that doesn't count.

 

Fwiw, all the springs in all my Xj's are still the original factory stock springs---- lol