TESTED: PRO CIRCUIT KTM500EXC FORK REBUILD

We asked suspension legend Jim “Bones“ Bacon at Pro Circuit to help us get our Upshift KTM500EXC dialed in for a recent ride from the Mexican border at Tecate, down to San Felipe on the Sea of Cortez side of the Baja peninsula. Bones explains the PC theory for getting the big KTM to work efficiently on a variety of desert terrains:

“TheKTM500EXC is a terrific off-road bike and KTM sells every one made each year. It’s great on fire roads and cruising along two-track trails. However, get in to the big G-outs or deeply whooped-out trails and the bike becomes a handful in a hurry. The soft, plush suspension that works great on fast fire roads is quickly overwhelmed when the rider hits an unexpected ditch or big rolling whoops at speed. Many times, the 500EXC is the bike of choice among larger riders who, by themselves, overtax the marginal stock suspension. Add a larger fuel tank and a backpack full of tools and the already under sprung suspension is way past its’ limit.

The 500EXC has suspension that is just too soft. Plain and simple, the forks ride too low, which makes the rear shock feel nervous and twitchy. Get into the big bumps and the shock will blow right through stroke and bottom out hard. Pro Circuit has come up with a solution for the big KTM without sacrificing the plush ride: The first fix involves addressing the correct spring rates for both forks and shock. Next, the fork valving is modified to make the stroke much more progressive while keeping the ride plush and working with the bigger fork springs. Additionally, the shock valving is altered for the same reasons; keep the ride plush but in sync with the heavier spring. We install our Pro Circuit Shock Reservoir kit, which replaces the stock reservoir and floating piston design with a bladder system that smooths out the transition between compression and rebound while increasing the nitrogen volume. Finally, we can shorten the suspension upon request as we do for many riders who feel the bike is too tall.

The final result is a plush and much more progressive ride and, with the center of gravity a little lower, better bike control.”

We have to say the Pro Circuit suspension set-up delivered confidence in all situations from sand whoops, to rocks, to square edge hits at high speed. www.procircuit.com

Pricing:
Fork Re-Valve And Set Up $194.95
Fork Oil, Compression Adjuster Knob, Low Speed Valve (X2), Piston Ring (Pair),
Piston Bands $178.75
Fork Spring .48Kg (Pair)  $129.95
Shock Re-Valve And Set Up$164.95
Shock Piston, Shock Oil, Shock Reservoir, Shock Bladder, Bladder Cap, Air Valve$214.45
Special P/C Shock Bumper$19.95

 

Chris Glaspell

Upshift, 23986 Aliso Creek Road Suite 450, Laguna Niguel, CA 92677

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