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Fisher unleashes Roscoe trail bike

HiFi goes carbon

By Ophir Sefiha
Published: Jul. 20, 2008
Gary Fisher's new-for-2009 Roscoe trail bike
Gary Fisher's new-for-2009 Roscoe trail bike

For 2009, Trek’s Gary Fisher brand built a new trail bike, the Roscoe, and refined its HiFi line.

Gary Fisher (the man) described the Roscoe as “a go-anywhere, confidence-inspiring bike.” The 5-inch travel bike features suspension technology co-designed by Fox and Gary Fisher.

The new Dual Rate Control Valve (DRCV) rear shock is an evolution of Fox’s successful RP23. While it still has three external adjustment settings and the on/off Propedal lever, the similarities end there.

The DRCV’s dual air chamber offers many of the benefits of a coil shock including greater small bump compliance and a consistent linear spring curve, but in a lightweight and highly tunable air shock, said Trek director of suspension technology Jose Gonzalez.

These benefits are accomplished in large part by the dual air chamber that contains a position-sensitive plunger valve that opens the passageway to the secondary air chamber at a predetermined point on shock travel. As the shock compresses through the first half of travel before engaging the second chamber only the pressure in the main chamber increases. As the plunger valve activates the secondary air chamber (at 40 percent travel), the main chamber pressure increases to nearly match the secondary chamber pressure. This allows for a seamless transition between the two chambers.

The DRCV weighs 310 grams.

Additionally, the repositioning of the shock’s upper eyelet to the middle of the shock body allows for additional air volume to be placed on top of the shock, which Gonzalez says saves weight and frees up valuable bottle-mounting space.

The Roscoe also features Fisher’s Active Braking Pivot (ABP), designed to eliminate rear suspension stiffening or locking up under heavy breaking loads. Putting the rear suspension pivot concentric to the rear wheel axle allows the suspension to remain active while braking. The design does require that the skewer be threaded off when removing the rear tire.

The hydro-formed aluminum Roscoe features a tapered 1 1/8- to 1 ½-inch headset and will come with bottle cage mounts above and below the down tube. The stays will fit up to a 2.5 tire.

Fisher will offer three Roscoe models ranging from $3,000 to approximately $5,000.

While the Roscoe is an all-day trail bike, the HiFi line is for all-day racers. For 2009, the aluminum frames drop 230 grams and gain a little stiffness by going to hydroformed tubing and carbon co-molded seatstays.

For '09 on the HiFi Carbon models, the rear swingarm becomes a new co-molded carbon affair to drop weight and improve rigidity. The shock mounts continue to be co-molded with the frame rather than simply bonded-on. Fisher’s industrial design manager Chris Carlson said that by orienting the shock mount’s carbon lay-up with the shock’s compressive forces makes for a lighter and stronger junction. It also creates an elegant aesthetic to this oft-forgotten portion of the bike.

Fisher will offer two all-carbon frame models, the 120mm HiFi Carbon Pro with a Shimano XTR/SRAM X.O drivetrain and the HiFi Carbon with a Shimano XT build. The aluminum HiFo lineup will continue to offer four models and also be available in two women’s models. The top end HiFi Pro and HiFi Carbon models will come with the custom-tuned Fox XV RP23 rear shock, which contains an Extra Volume air can designed exclusively for Fisher. The HiFi Pro Carbon and HiFi Pro aluminum will spec Fox’s new 120mm travel RP24 fork, which incorporates the multiple setting Propedal adjustment found in Fox’s RP23 rear shocks. As of now, this fork is proprietary to Fisher.
Product manager Aaron Mock said a size medium HiFi Pro Carbon will tip the scales at 23.7 pounds.

Both bikes share Fisher’s Genesis G2 geometry, which aims for more neutral handling by increasing the fork offset. The idea, Fisher said, is “making any rider more confident.”

The HiFi and the Roscoe should be available in late September.

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