Suspension Options
When I was looking for suspension upgrade info for my KLX 230R I didn't find much, so figured I would compile what I found so other people can use it.
Stock fork rate = 0.35kg/mm.
Fork Installed preload =5mm
Total fork travel = 250mm
Stock shock rate = 4.8kg/mm
Total rear wheel travel = 251mm
For my 185lbs (no gear) this gave a total front sag of 82.5mm, which is 33% of total travel but would bottom off the smallest bump. The total rear sag was 89mm, on the second to last notch. On the last notch there was no static sag, which is not recommended.
Resources - the thumpertalk CRF230F forums had the most info on upgrade options.
Upgrade options:
Cannon Racecraft https://cannonracecraft.com/ - The only place I found that made an assortment of CRF230F springs which is a 30mm diameter and 597mm long. The KLX springs are 30mm diameter but 612-614mm long. So with a simple spacer to make up the difference in length CRF230F springs work perfectly.
BBR - has a CRF230F but at a 0.55kg/mm will be much to stiff for most people.
Bruce's Suspension https://sites.google.com/site/brucessuspension - bruce provides full service on the forks and can modify the stock progressive springs from the CRF230F to fit your weight upto total rider weight of 200lbs. Bruce can also modify the existing damper rods of the KLX to have really good performance. This is the most cost effective solution, but requires you to send the damper rods to him for modification. Bruce also sells Hagon shocks which are a direct replacement for the OEM shock, come with a 6kg/mm spring and are a significant upgrade over stock.
Bradley Performance https://www.bradleyperformanceproducts.net/kawasaki-klx-230s- Sells springs and shocks for the KLX 230S along with fork emulators that can be used in the R or S model as they both use the same 37mm forks.
HiVolt Spares - Offer a new shock and some adjustment to the hydraulics of the damper rods. Note their fork upgrade kit does not include springs. I had trouble finding any sort of reviews on this kit and shock.
I went with a 0.48kg/mm springs from Cannon Racecraft, the fork emulator from Bradley Performance and the Hagon shock from Bruce. I only have one test ride on the new setup but it made a huge difference. No bottoming out on the forks, good compliance through full range front and rear. With the fork emulators (17mm) and the 597mm long spring I have an effective preload of 7mm instead of the stock 5mm and get 60mm of total sag on the front (using riding weight in gear of 200lbs), which is a little on the stiff side. So I'll be experimenting with lower fork position and adjusting rear sag to put more weight on the front. I also put a zip tie on the fork tube so I can see how close to bottom out I'm getting on the next ride. I adjusted the preload on the shock to get 77mm of sag which is 31% of travel, slightly on the softer side. I'll experiment with reducing the shock sag to 70mm and see how that feels.
I'm sure going 100% with bruce would have resulted in a good setup as well, I just didn't want the bike to be down for several weeks from shipping parts back and forth, but this being the cheaper option is probably a good deal for most people, also Bruce has a long reputable history to backup his work.
Note these upgrades don't turn the suspension into a MX suspension. It simple makes it a much more capable trail bike and behaves significantly better than stock suspension.