VARIOUS INVENTIONS (in addition to full bikes)
From CCPROTO and continuing for two decades, Cunningham made contributions to the evolution of the mountain bike, some still found on current bikes:
- welded & heat treated aluminum mountain bike frames
- compact mountain bike, cyclocross and road frames (1)
- Progressive cross-country mountain bike frame geometry (2)
- Charlie manufactured a series of tubular fork crowns that accepted brazed or silverbrazed-in blades:
- Type I mountain bike touring fork
- Type II mountain bike racing fork
- Type IV cyclocross fork
- (His Type III fork had a unitized tubular crown and blade design. Inexpensive to manufacture and called the Unicrown, it was widely used in early production mountain bikes.)
- Introduced 135 mm rear dropout spacing when 125mm was the standard, producing a stronger wheel with zero-spoke-dish and optimal chain alignment
- Wide-range 1x gearing for mountain bikes (3)
- Extra wide 118mm front mountain bike wheel for improved shock absorption and lateral stiffness
- Identified the process for analyzing individual and collective tread block function which was used to design the Ground Control and other top-performing mountain bike tires. The Ground Control, named by Jacquie Phelan, was the first mountain bike specific tire producing a quantum leap in performance. More Ground Control tires have been sold than any other.
- Cunningham invented the Grease Guard Bearing System, which allows bicyclists to completely flush bicycle bearings with clean grease in seconds, displacing the water and abrasives that inevitably get past seals. This greatly increases component life, reducing waste, and the time and money spent overhauling and/or replacing parts. Grease Guard’s effect on equipment longevity is substantial, but it conflicts with bike industry needs. The prevailing business model prefers components that require regular replacement to those that can be maintained.
- Designed the Roller Cam Brake, patented and licensed to Suntour in 1985. The brake stud mounting location, the brake arm design, and the roller/cam linkage combine to eliminate flex, maximizing braking accuracy and power. (Cunningham’s Roller Cam brake also introduced the linear centering spring, which is still used on most V-Brakes today.) Cunningham has continued to perfect the brake. With improved linkages, brake arms, springs and bearings, the brake has evolved to an exceptional performance level. Cunningham believes the current form, called the Cunningham Lever Link Brake, offers the best bicycle rim brake of all time.
- Created the Chain Pup, the smallest and lightest multi-tool for bicycles, launching an entire new product category.
- Invented the Fitfinder, a calibrated adjustable stem that allows the user to adjust and optimize the handlebar location during riding for the ideal fit. The Fitfinder dimensions are then used to produce a custom stem, or to transfer the ideal fit to other bikes.
- Promoted the importance of the rider’s pedals being as close as possible to the center-plane of the bike for the best technical trail performance and cornering clearance. Now called the Q-Factor.
- CCPROTO introduced light, machined aluminum and magnesium parts that preceded an industry-wide emergence of similar CNC machined components beginning in the mid-eighties. (See CCPROTO’s seatpost collar and quick release lever, brake arms, chain guide, and magnesium stem with removable cap for easy handlebar replacement.)
- Bottle cage for light, biosafe PETE 1.0 and 1.5 Liter Crystal Geyser style water bottles
- 4130 Gooseneck stem with removable cap for drop bars
- Toe Flips for fast, easy entrance into toe clip pedals
- Taper mounting of handlebar stems
(1) Charlie’s first mountain, cyclocross and road bikes were designed with compact frames, sloping toptubes and long seatposts. To him the structural and performance advantages were obvious. By shortening the top tube, seattube and seatstays, the frames used less material and were thus lighter. The shorter tubes also improve frame stiffness in bending and torsion, and compact frames absorb trail or road shock better while offering greater stand-over clearance. The bikes below with descriptions and notes can also be found in the Bike Gallery section.
The first custom-made mountain bikes copied the popular Schwinn Excelsior newspaper bike with 44” wheelbase, 18” chainstays, 68 degree headangle, 12” bottom bracket. Charlie’s CCPROTO was 41.6” wheelbase, 17” chainstays, 70.5 degree headangle, 11.6” bottom bracket, similar to the geometry used in following decades for cross-country mountain bikes.
Charlie’s personal 1x mountain bikes:
- (1979) CCPROTO: 41t chainring, five speed 13-34 freewheel
- (1982) #12: 41t chainring, seven speed 11-38 freewheel
These are examples of the first wide range 1x mountain bikes with titanium chain guides to prevent derailment. Wide range freewheels were not available, so Cunningham made his own by machining and silver-brazing cogs as necessary. Rear derailleurs were modified to work with the wider ratios.