The 70s Racing Heritage: HONDA CBX1000 Custom by Tajima Engineering
Tajima Engineering's CBX1000
The CBX1000 was introduced in 1978 as Honda's new flagship model, and its 1047cc DOHC 4-valve inline-six engine was truly groundbreaking. The subdsequent minor changes such as installing a cowl with a shape reminiscent of the CB-F Integra and adopting a mono-suspension at the rear made it seem like a bridge between the motorcycle scene of the '70s and the '80s. This machine is an early model CBX with twin shocks, which was modified by Tajima Engineering. "The owner has a lot of experience on the race track, and he got the stock bike with the intention of customizing it, but as is often said, the handling was poor and it could not be ridden in a straight line. So we modernized it with frame reinforcement and laydown modifications. After the modifications, the handling is now like the current 17-inch CB1300SF (SC54) model, and the owner says it feels great," says Mr. Murashima, the shop's representative.
"The reason for this process was that the CBX is the same age model as the CB-F, so we thought it would be a good idea to use the same technique. The porting and crank cutting (weight reduction) of the engine to make the intake and exhaust flow smoother are also done in the same way as CB-Fs at our store. The engine displacement and carburetor are stock, but the engine runs smoothly. The suspension was modified from the stock parts of the time, which are quite heavy, to reduce the overall weight to 240kg (the CBX stock is officially listed as 249kg dry, which can be considered to be over 270kg with the weight of equipment), making it almost 30kg lighter. The owner is a person who does a lot of work, including painting, and he seems to be having a lot of fun on the racetrack with this bike." The frame reinforcement (15 to 22 locations) and 17-inch front and rear wheels applied to this bike have become established as part of Tajima Engineering's CBX modernization menu and have become standard.
Handle
The 30mm offset steering stem (CBX stock is 50mm) and 43mm diameter front forks (CBX without cowl is 35mm) were taken from the SC54 (CB1300SF), and Tajima Engineering has the know-how to convert these stock parts. The handlebar is from Z PARTS, and the gauges are made by the owner himself, using a carbon-patterned mold of the stock gauges.
Bodyworks
The single-seat-style double seat is the Corbin Gunfighter. This product was widely seen during the custom boom of the '90s, and it also offers good holding performance.
Engine
The specs of the DOHC 4-valve inline 6-cylinder 1047cc engine itself are stock, but Tajima tuned it by applying CB-F modifications such as port processing and crank weight reduction to make it light but leave it with solid traction. The sliders are made by OVER.
The 6-barrel carburetor is also stock of the CBX. With a significant weight reduction, solid engine construction, and carb maintenance, the specs are ready for racing.
Intake & Exhaust
The rear brake caliper and disc are from a CB400SF, and the hand-bent 6-2 full titanium exhaust system is a one-off product.
Chassis
The simple steps are also constructed using Honda OEM parts. The diamond-type frame has been reinforced with head pipe extensions and other reinforcements.
The front brakes are NISSIN SC54 (CB1300SF) 4-piston calipers and CBR600RR discs. The 3-spoke 3.50-17/5.50-17 size wheels are also stock parts from the CBR600RR.
The aluminum square swingarm is a stock CB400SF with an added lower sway bar. Generally, using 400cc parts for liter-class models is considered inappropriate. However, Tajima Engineering employs CB400SF arms in this manner after obtaining strength data.
Gallery
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Specifications
Original Source of this Article
Heritage & Legends
editor
Hakuyo
A foreigner who rides in Japan, Japanese call this "Gaijin Rider". Third year in the Webike global team. He feels and shares the real bike life in Japan then presents you how interesting Japanese customs are.
