GMC Topkick Dual-Suspension Mountain Bike
21-speed mountain bike features a full-suspension, strong aluminum frame
Floating beam suspension design is mated to a Zoom suspension fork with elastomer/spring technology
Microshift push shifters and Shimano TZ-30GS derailleur
Strong aluminum wheelset featuring V-shape rim profile and high-flange alloy hubs
Front and rear Promax disk brakes work great, even in adverse conditions
Frame: 26-inch full suspension aluminum MTB frame
Fork: Zoom CH-386 suspension fork 65mm travel
The GMC Topkick 21-Speed Mountain Bike features a full-suspension, strong aluminum frame that utilizes a floating beam suspension design that is mated to a Zoom suspension fork with elastomer/spring technology. The Topkick's drivetrain starts with Microshift push shifters. These shifters control Shimano's tried and true TZ-30GS derailleur. The drivetrain finishes up with a strong aluminum wheelset featuring V-shape rim profile and high-flange alloy hubs. Stopping is handled by Promax disk brakes on the front and rear. These brakes are vastly superior to rim brakes, especially under adverse road conditions. True to it's GMC roots, this bicycle is rugged, good looking, and built for the long haul.

GT Avalanche Expert Hardtail Mountain Bike
Frame: GT Triple Triangle design 6061 butted aluminum with pressure formed downtube
Zero stack head
Fork: RockShox TORA, 85-130mm u-turn with rebound adjustment.
Crankset: Truvativ 5-D with Powerspline 44,32,22
Bottom Bracket:Power Spline Cartridge Sealed
Avalanche Expert Hardtail Mountain Bike
EVO (UK), Jan '06 - "If you fancy throwing yourself down a mountain on a bike, then this is the one to do it on. Never before seen on a production bike, the eight-speed gearbox is fitted inside the frame to keep it clean and clear of rocks, etc. The adjustable Fox 40 RC2 forks have up to nine inches of travel and the hydraulic disc brakes would put most BMWs to shame. Rider must provide own insanity."
GT must be commended for its commitment to developing the iT1. The sooner other manufacturers embrace internal gearing, the better. If you live bikes and love to sit at the forefront of technical innovation, look no further. Undoubtedly, GT has brought us one step closer to the future of the sport.
A gravity fiend couldn't ask for a better component spec and the internal transmission,m although unconventional, performed flawlessly.
The internal transmission separates the drivetrain from the suspension, relieving the drivetrain from inefficiencies caused by the rear suspension movement and allowing for a different wheel path to better the suspension.