2008 KTM RC8 1190 - Austrian Attack

KTM Finally Makes Its Entrance Into The Serious Sporting Scene With The Svelte RC8 1190

writer: Alan Cathcart
photographer: Herwig Peuker

KTM's arrival on the sportbike scene with the lean, mean RC8 1190 was worth waiting for. Ever since the Austrian company unveiled the prototype RC8 V-twin sportbike at the Tokyo Show in October 2003, we've been waiting for the finished product. The final production machine features the same distinctive styling from designer Gerald Kiska but with an all-new engine that raises capacity from the showbike's 990cc to 1148cc. The chance to ride the end result at the Ascari Race Resort near Ronda in southern Spain confirmed that this small but perfectly formed contender is indeed an exciting package unlike any other in the marketplace.

Just looking at the RC8 helps corroborate this. Kiska's design still remains fresh and individual, especially in white or black rather than the trademark KTM orange. But the RC8's unique qualities are also in function as well as form.

As soon as you sling a leg over the V-twin you notice the seat seems much lower and more spacious than expected, and the bike feels very narrow and compact overall, with your knees tucking in tight to the rear of the 4.4-gallon fuel tank. Set at a surprisingly low 31.7 inches for a modern sportbike, the KTM's saddle doesn't force all your weight onto your wrists (although the seat and footpegs are adjustable and can be raised by 20mm). "Our aim was to use the compact dimensions of our 75-degree V-twin motor, even in larger-capacity 1148cc form, to produce a bike with the engine performance of a Ducati 1098 but the chassis of a Honda CBR600RR," says RC8 Project Leader Wolfgang Felber. "But we wanted to be sure there was space for the rider to move about in the bike, to feel at ease in using his body to help maximize the handling. And it is important to be comfortable, since this brings confidence." KTM has you sitting in the RC8 rather than perched atop it, with the handlebars set forward of the 43mm, upside-down WP (the Dutch suspension specialist owned by KTM) fork's upper triple clamp.

Footpeg brackets (and seat) are adjustable in two positions 20mm apart, with additional adjustability in the bars as well.

Rear ride height is adjustable using this eccentric pivot on the rear suspension linkage. Rear WP shock has both high- and low-speed compression-damping adjustment.

The fully adjustable 43mm WP inverted fork holds a pair of monobloc Brembo calipers biting on twin 320mm discs for impressive stopping power.

The cockpit features a highly idiosyncratic digital dash; you'd get info overload if I told you everything this covers in either race or road mode. But while the large digital speedo reading is easy to pick up, the bar-graph tachometer across the top is much less so, with small numbers making it even more difficult (good thing there are two-stage shift lights atop the dash). The lack of fuel gauge or gear indicator is an oversight that should be corrected pronto, especially on a bike as deceptive as this one with such a smooth, linear power delivery and flat torque curve.

Because that's what the KTM's engine is: deceptive. Light the fire via your right thumb, and the 103x69mm eight-valve V-twin settles into a fairly fast 1500-rpm idle speed, with a higher-pitched exhaust note than a 90-degree Ducati. The 1148cc engine uses a dry-sump lubrication system similar to the 990cc LC8 engine used in the Duke series, with the exception of the four-liter oil reservoir integrated into the crankcases. Forged Mahle three-ring pistons force a compression ratio of 12.5:1, breathing through 43.5mm intake/38mm exhaust valves (up from the 990's 38mm/33mm combination) actuated by finger followers instead of bucket tappets. The double-overhead camshafts in each cylinder head are chain-driven instead of using the composite chain/gear drive of the 990; full gear drive is "too loud and not really reliable enough," Felber states, adding, "In my opinion, you should only use gear drive when you have a very even-firing motor like a four-cylinder. In this application on a V-twin engine there was too much gear shock, so we didn't use it."

The engine's throttle response from the Keihin 52mm throttle bodies is immediate, dialing up revs even more quickly than a Ducati thanks to what Felber confirms is a light flywheel setup. Yet this free-revving motor is also torquey, pulling out of turns from as low as 4000 rpm with a linear build of power all the way to the 10,700-rpm soft rev-limiter (followed 300 rpm later by a hard cut-out). There are no steps in the power delivery and especially no dip at around 5000 rpm such as you encounter on a Ducati; perhaps this is why the KTM's power delivery doesn't seem quite as exciting as its Italian rival's. There isn't the same impression of a midrange hit on the Austrian bike, which is even more refined in its fueling off the bottom and certainly has a smoother path to your appointment with the rev-limiter. Without a side-by-side comparison it's obviously impossible to say which bike is faster, but Felber claims the RC8's 155 horsepower at 10,000 rpm, with 88.5 ft-lb of torque peaking at 8000 rpm, is comparable on the Mattighofen dyno to a Ducati 1098's claimed 160 horsepower and 90.4 ft-lb.

Regardless, the way the KTM engine delivers the goods is impressive, aided by the crisp gearbox and the light-effort wet clutch, which doesn't cramp your left forearm sitting in traffic or negotiating city streets like some other V-twins I could mention. And the twin counterbalancers do a good job of ironing out vibration from the 75-degree motor; there are a few tingles through the footrests once you rev it above 8500 rpm, but just as with the smaller 990cc family of KTM models, in normal use the RC8 is as smooth as a 90-degree V-twin.

Stripped of its angular bodywork, it's easy to see how centralized the RC8's overall mass is. Note the crossover tube between the separate headers for each cylinder leading into the underengine exhaust chamber.

The 1148cc 75-degree V-twin engine in the RC8 is actually slightly lighter than the previous 990cc version at 137 pounds. Note the integrated oil reservoir for the dry-sump lubrication system at the front of the engine cases.

Employing a chromoly steel tube space frame, the KTM utilizes the engine as a stressed member, with the swingarm pivoting in both the rear of the engine cases and the pivot section built into the frame.

The location of the exhaust is another key element in the KTM's unique architecture, even more so than on a Buell. The twin catalysts carried inside the large oblong silencer are located immediately beneath the clutch to help centralize mass in the interests of quicker handling. Weight transfer on the RC8 is much less of an issue-power wheelies aren't so frequent, and you don't lift the back wheel and start street-sweeping the tarmac under the demonically late braking offered up by the radial Brembo four-pot monobloc calipers (although the 220mm rear brake with twin-piston caliper is pretty pathetic and works only at the very end of the pedal travel).

These Brembo brakes offer much better feel and response on the KTM than on a Ducati 1098, even on 10mm-smaller 320mm floating discs, which impact the steering less in terms of gyroscopic effect. The KTM shrugs off bumps around fast turns, and high-speed stability is excellent in spite of the lean, light architecture of the RC8 package. The low, slim design of the dry-sump motor has allowed Felber and his engineers to position it where they wanted to in the 56.3-inch wheelbase.

The result of that compact engine build is a 54/46 percent front-end weight bias that's a key component of the RC8's fluid, intuitive handling. A chromoly steel tube spaceframe is employed with the KTM, using the engine as a fully stressed member mounted at four separate points with the swingarm pivoting in both the engine cases and a dedicated portion of the frame. "This creates a stiff structure that still allows the bike to 'talk' to the rider," Felber says. The RC8 steers like a 600, and thanks to the grippy Pirelli Dragon Supercorsa Pro rubber you can carry what seems like an insane amount of corner speed, the WP fork eating up bumps while delivering excellent feedback from the front tire. In a sequence of bends that sees you flipping the bike from one side to the other in swift succession, the RC8 is almost as sweet-steering as the 690 Duke and feels as nimble as a Ducati 848 in changing direction, even though it's fitted with a wide 190/55 rear tire. And when you do trail-brake into a turn, the RC8 stays exactly where you choose with completely neutral steering response despite the sharp steering-head geometry of a 23.3-degree rake angle matched to just 90mm of trail. However, once you've got the rear tire nicely warmed up you'll want to dial in a few extra clicks of the WP steering damper to stop the bars from wobbling in your hands as you accelerate hard exiting turns.

But that's about as unsettled as the RC8 ever gets at either end. It's very consistent in its handling; you know what to expect every time you make a move. Another component in this reliable character is KTM's clever back-torque-limiter system, which does away with the slipper clutch Felber admits his R&D team considered fitting to the RC8 before rejecting it in favor of a system controlled by the Keihin ECU. By operating one butterfly on the rear cylinder's throttle body, the system is able to keep some engine braking available while still eliminating its negative effects on handling during hard braking. You really get the feeling this bike was designed by people who ride hard and know what they want a bike to do.

Unfortunately the only aspect of the RC8 where the development came up short-at least according to Felber-is in weight. "We wanted to make the bike as light as possible, but I'm extremely disappointed that I've failed by [19-20 pounds]," he admits. "My aim was to get it below [418 pounds] with [4.3 gallons] of fuel, but [437 pounds] is as light as we could make it. I'm pretty unhappy about that. I want to get below that [418-pound] wet barrier with a future version!"

KTM has also already addressed the issue of aftermarket bling with an array of RC8 PowerParts. These include a full Akrapovic titanium race exhaust, race stands, tire warmers, a tire pressure/temperature monitoring system, reverse gear linkage, carbon-fiber bodywork (or a fiberglass bodywork kit that is easier on your wallet), Dymag carbon wheels, forged aluminum or magnesium Marchesini wheels to replace the already pretty light standard cast-alloy numbers specially made for KTM by the Brembo-owned Italian manufacturer, and so on. But apart from the race exhaust and the ECU chip to go with it, there are no power-up performance parts for the RC8 motor-yet.

[The unfortunate part of this story for U.S. enthusiasts is that the RC8 won't make it into American showrooms as an '08 model. KTM will manufacture 2500 examples of this base-level version of the RC8 in 2008, but "by the time we would be able to get units to dealers in the U.S. it would already be June or July, and the '09 model would be just around the corner," states Tom Moen, KTM North America's media relations manager. "It just makes more sense to wait a bit and have the '09 models right off the production line. The '09 RC8 in American guise should be available around August, no later than September of this year." -Ed.]

Although it's only being discussed within the KTM management at this time, there's a good chance we can expect the debut of an upgraded version of the RC8 as well as a full 1200cc RC8R race-ready version with which KTM will launch a full-on attack on the FIM Superstock World Cup in a year or so. The RC8R will also provide the basis for KTM to go superbike racing in countries like the U.S. and Germany before joining in the World Superbike arena-most likely in 2010-with a full-race twin-injector engine that's already under development. There's also a naked bike in the works based on the Venom concept bike displayed back in 2004, though don't hold your breath for that to arrive in KTM showrooms anytime soon. But for sure there'll be an 1190 Adventure, because one reason KTM opted to retain the 75-degree engine architecture was to fit a 21-inch front wheel in a dual-purpose model application. And those are just the ones we know about.

The future's bright . . . orange. And the RC8 is where it all begins.

'08 KTM RC8 1190
MSRP: $NA

Engine
Type: Liquid-cooled, 75-deg., DOHC, 4-stroke V-twin
Displacement: 1148cc
Bore x stroke: 103 x 69mm
Compression ratio: 12.5:1
Induction: Keihin electronic fuel injection, 52mm throttle bodies, single injector/cyl.

Chassis
Front tire: 120/70ZR-17 Pirelli Dragon Supercorsa Pro
Rear tire: 190/55ZR-17 Pirelli Dragon Supercorsa Pro
Rake/trail: 23.3 deg./3.5 in. (90mm)
Wheelbase: 56.3 in. (1430mm)
Fuel capacity: 4.3 gal. (16.5L)
Claimed wet weight: 437 lb. (198kg)