2019 Beta Sachs ZF fork overview
Beta has heavily marketed its new ZF fork as the highlight of the 2019 Beta lineup along with other changes in the overall bike design. The 2019 Sachs fork is all new, inside and out. So how do they perform?
The Sachs forks now have both compression and rebound adjusters up top along with a new preload adjuster on the compression leg. There are still springs in both legs, which means its not a true SFF (separate function fork). However, all the rebound damping is contained in one leg while compression damping is mostly shared between the two. There is nothing inherently wrong with this design choice as the forks act as one single unit when clamped/bolted together. Beta has also claimed their anodizing on the fork legs is much more durable. This will be determined as time moves forward.
The problems arise in the form and function of the compression clicker, or lack there of. Other suspension companies(I’m looking at you WP) have tried to incorporate both adjusters on top, but in practice, it simply does not work. The adjusters up top are in control of the mid valves bleed or bypass. On rebound this works fantastic. On compression this does very little. A midvalve compression adjuster does extremely little to the low speed damping characteristics and only minor changes to high speed damping. The compression adjuster, or entire compression leg, is effectively useless with the valving implementations discussed below.
Betas valving settings out of the box are a mixed bag. The rebound damping is a massive step in the right direction compared to the pre-2019 forks. Good job Beta. The compression damping rather, is nearly non existent. The base valves on both legs have very very soft and wimpy valving, that makes them almost entirely ineffective. The compression leg has massive holes near the top of cartridge eliminating any low speed damping. On top of that, the midvalve shim stack is clamped completely shut. Rather than oil flowing through the adjuster, it seems Beta is trying to push fluid through the basevalve. This simply does not favor traction or comfort, especially when there base valve has very little damping contribution to begin with. To make matters even worse, there are no base adjusters on the bottom of the fork.
In typical Beta fashion, they have also implemented a massive amount of fork spring preload. This along with very soft springs makes for a harsh fork that likes to deflect and push in corners. Your best bang for buck improvement is to apply the proper springs (see our handy spring charts at www.allmotoperformance.com/spring-charts) and remove the excessive spring preload. To remove preload you need to use shorter springs or trim the spacers in each leg. On the rebound leg there is white plastic spacer on top the fork. On the compression leg there is a thick aluminum spacer at the bottom of the spring. We prefer to trim the spacers as this allows use of stock length springs.
To start we apply correct springs pending rider weight and remove the excessive fork preload. Then we turn our attention to the damping. The rebound takes very little to improve. The compression leg takes the most modification. We first plug the massive holes at the top of the cartridge to turn the fork into a traditional OC fork. From there we can apply logical valving changes that not only make the adjusters more effective, but improve traction, comfort, control, and bottoming resistance. The only major thing we would like to see is a compression adjuster on the bottom of the fork leg.
If you’re looking for a massive step up in performance, we suggest the MXT Lucky kit. We install these kits and provide our own custom valving to suit each individual. These are a drop in kit that replaces all of your fork internals with a true works setup. This is a recommended and worthwhile upgrade to anyone looking for a truly competitive setup. For more info, check them out in the links below.