Long-Term KTM RC390 Suspension Upgrade: Andreani Fork Kit Installation

Improving fork performance with fully adjustable drop-in cartridges.

Close up of Andreani fork caps

In Search of Speed!

Carrying speed through corners requires confidence—confidence that your tires will stick and that the bike will remain stable and on line. My focus as of late has been to improve the KTM’s handling and increase front-end feedback. In this installment, I make great strides with an Andreani fork kit.Brian J. Nelson

WRIST: Ari Henning
MSRP: (2015): $5,499
MILES: 2,966
MPG: 57
MODS: Fork cartridges

In my last long-term update I reported on replacing the KTM RC390's stock WP shock with a custom-made and highly adjustable JRi unit (CLICK HERE to see Long-Term RC390 Update: JRi Shock Installation). Bolting up the JRi shock brought my rear sag into the right range and has allowed me to tailor the suspension motion (via damping) to better suite the kind of aggressive riding I enjoy most.

As is always the case when you’re developing a bike for a specific purpose—which in this case is track days and racing, if you haven’t already figured it out—improving one thing invariably exposes another area’s weakness. While I didn’t really have any major complaints about the fork on the street, when pushed hard at the track the front end gave me zero feedback and prevented me from having the confidence to carry more corner speed. And on a small bike, corner speed is king!

The RC has an attractive inverted fork, but despite that sophisticated appearance the fork is non-adjustable and internally it's quite crude, without any of the tunable components of a normal cartridge fork. Add to that the fact that it's sprung with progressive springs—rarely a good fit for track riding—and I knew a rebuild was needed. For that I turned to David Behrend at Fast Bike Industries (www.andreanigroupusa.com).

Andreani fork cartridge kit for the KTM RC390

It's What's Inside That Counts

The Andreani cartridge kit completely replaces the stock fork internals and fork caps. The setup is fully adjustable, with spring preload adjusters on both legs (gold caps) and compression damping on the left leg and rebound damping on the right (silver hex-head bolts in the center of the preload adjusters).Photo: Julia LaPalme

David distributes Andreani components, and the Italian company’s cartridge kit for the RC390 is the real deal. It has proper compression and rebound valves and comes with straight-rate springs that are selected based on your weight, all for $699. Installation will cost you a bit more, but even then the total price is still a couple hundred bucks less than other aftermarket cartridge kits not to mention $1,000 less than the $1,750 Cup-bike fork which, it’s worth noting, still needs to be valved and sprung for the rider’s weight.

I sent my fork off to David and he had it back to me in a little over a week, with the beautiful machined-aluminum fork caps the only indication that anything was different. I slipped the tubes into place, set sag, wrote down the compression and rebound settings in my logbook, and headed out to Chuckwalla raceway.

It’s easy to think a bike feels better, but what I love about testing at the track is that the lap timer is always there to give you hard data. Compared to the last time I took the RC to Chuckwalla, I was lapping the course 2.5 seconds faster on average. And I know exactly why. It’s because I was actually getting some feedback from the front tire so I knew how hard I could push it at corner entry. Better front-end feel and more controlled fork motions made me much more confident through the corners, especially while trail braking. Previously I was left wondering how much grip I had in reserve, but with the more communicative front end I had a better grasp of just how much of my traction budget I was using. Overall the bike felt more balanced while braking, turning in, and at full lean.

Some of the credit for faster lap times should go to the stickier Bridgestone RS10 tires I was running (more on those in a bit), but even so, it’s clear the RC is moving in the right direction. There’s still some room for improvement, however (there always is!), so I’m eager to get back to the track to fine tune the damping and experiment with some ride height changes. It’s nearly time to wire this thing up and take it racing!

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