I have an 02 Ultra, the left fork has a cartridge in it. I am looking at the Progressive springs to put in them, or should I just buy a new left fork for a Road King and get rid of the Cartridge all together. Any ideals ?

Whatever you do you'll have to do it on both sides.
I've used progressive springs before, they sure help stop "fork collapse" during braking.

What's wrong with the cartridge style fork?

Well I didn't understand this at all.   I had never heard of one side being different than the other.  It just didn't make sense.  Of course a good many Harley decisions (changes) haven't made sense at times. So I did a bit of research only to discover that the bikes/year in question were ones I never owned.   I've got more to look into now.  Perhaps I'll get back to you with a couple questions of my own.  Oh, is there something wrong with the left fork?


Peace

Honda Valkyrie is made that way. I'm told the bike will not handle if both sides are conventional.

I am not sure why, but all of the HD fairing models (ElectraGlide Std, Classic & Ultra, and the Road Glide) 2002-2005 have the cartridge on the left leg only.  The right leg is a conventional style. I have heard of a lot of people going to conventional suspension on both legs with no noticable difference in handling.

There is nothing per-say wrong with the cartridge on the left side. It is time to change the oil due maintenance. After reading how to change the oil in the cartridge side(a pain) and the forums it seems like changing to fork out to the conventional one might be the way to go.

Beware, the handling will be completely different... it's one of those things if you know somebody or a good shop take it to them and have them do a nice professional job on it:-)

The logic behind the addition of the cartridge on the left was to smooth the ride. The standard shock would provide the rigidness and support and the cartridge shock was to damper movement and smooth the ride.

After a couple of years of customer feedback HD realized the very sight improvement (almost not noticeable in my opinion) in ride comfort and handling did not out weigh the additional cost in manufacturing and owner maintenance. Of course it cost less to use two of the same part than two different ones. Also for customers who did their own maintenance it was also easier and cheaper to maintain the standard shock.

Like a couple of others said, unless you are having problems with the left cartridge, or you ride enough to where you are changing shock oil more than once a year and want to make that easier, or you want to change the ride or height ... I would just leave it as is.  Since you're just now asking on an '02 sounds like just having the oil changed at the shop once every few years would be cheaper and easier than changing the shock.

If you do change it you will probably not even notice any difference in performance or handling. It will handle just like every Ultra before 2002 and after 2005 that ran standard shocks on both legs.

I always go with if it ain't broke or it won't make it better... don't fix it!

Not to contradict you BallOut but I can tell you I notice the difference as it's a lot less thump on those bad spots on the roads... at least that's been my observation.

I've never ridden one with the cartridge leg. Overall my 07 is pretty smooth but does ride a little rough in the front on really bad roads.

Black9 - are you saying it makes enough of a difference and would be worth it to switch my left leg to the cartridge type like the '02 to 05s ?

Popper, I have always felt the newer Ultras had a nice enough ride, at least for me, with the stock damping rod forks.  But if you were going to do it you would probably just put cartridges on both sides to get the full advantage of the cartridge forks.

However a much less expensive way to go may be to add the The Gold Valve Cartridge Emulator by RaceTech

http://racetech.com/html_files/EMULATORGV.HTML

I have never ridden a bike with the RaceTech Emmulators but they do get a lot of good reviews.

From what I have found the cartridge style fork just seems to smooth the ride out... to change them out of course you'll need a fork compressor tool. Usually they last a while unless you live on a long stretch of bumpy roads but usually they last quite awhile and don't require the fork to be changed out too often. If it were me the interval for changes would be between 10 to 15k miles... HD has conflicting intervals in different model year service manuals but it's what you feel comfortable with. Heck now the steering head bearing is good for 50k miles... the frames and components have become a lot more stable over the year and many are finding that the fluids in the moving parts are taking the beating they use to because of the newer frame designs and suspensions.