Front and rear suspension mods

[redbeard]

I got my pink slip the day before thanksgiving!!  Now that i own it i need to get the second gear sorted out and add a oil change bung in the pan.  I talked to Robert about doing the front and rear suspension.  Any body have any thoughts or comments on bikes that have been modernized? 

[Country Joe]

 I have yet to hear of anyone that has upgraded the suspension on their FJ and decided that they regretted doing it. Both ends are almost always under sprung and the damping was marginal when they were brand new, needless to say shocks do not get better with age. I have the RPM fork valves and .85 kg. springs in the forks on my 1993 FJ and the original shock. The front end is much more compliant than the rear, but a new shock is not in the budget right now. The best bang for the buck mod is the GSXR or YZF rear wheel swap. I can't recommend it nearly enough.

[camo]

Hey Joe how much do you weigh with all your gear on? Im 110kg with my gear on and about to put RPM valves and new springs in my 1992. was thinking of .95kg or 1.0. finding it difficult to get a good idea from the shop about ideal spring rate with the valves.

As a wider point im assuming with the valves a progressive spring is not worth bothering with, more likely a straight spring??

Cheers

[Pat Conlon]

Camo, when installing the RPM fork valves, use the spring rate suggested by RPM.
.95 kg/mm or 1.0 kg/mm is too stiff for the valves (as they come from RPM)

Don't confuse the fork spring rates used with Race Tech Cartridge Emulators with the spring rates used with RPM's IAT valves.

Apples to Oranges.

[racerrad8]

Camo,

The RPM fork valves will not work properly and I doubt you'll be happy with spring that heavy.

Please read this file for explanation: http://www.fjowners.com/index.php?topic=7486.msg66934#msg66934

There is a spring rate recommendation listed at the bottom of the fork valves. People who have not followed have been unhappy until the recommended springs are installed.

If you have any questions please email us.

Randy - RPM

Edit...thanks Pat

[camo]

Pat and Randy thanks so much for your advice. Havent opened the fork valves packet yet as planned to do the job over xmas (if i had i might have found the answer to my question already) but will have a look tonight.

Your both Champions.

[racerrad8]

Camo,

.85kg springs are what would be recommended for your weight with the RPM IAT valves.

Robert

[camo]

Thanks Randy,

I read through the other thread and admit like the other guy .85 sounds low, but I trust that you/ many others know more about this than me so wont question it. Will get the .85 springs and will let you know how i go.

Thanks again.

[FJmonkey]

When I got my springs and RPM valves I got the .85 rate springs. I was about 180 lbs with no gear and the front performs really well. That is how you discover how crappy and old OEM shock can be.