As featured in Velocity’s Season 2 of Cafe Racer TV the Dime City “Four Hundred” our desire with building the four hundred was to not only resurrect another long since forgotten pile of rusted motorcycle parts, but to pay homage to the gods of speed. Throughout the entire build process it was our intention to craft a machine that not only performed well on the track, but one that looked the part and was dripping with simple vintage hues.
We started out with a horrid mess of a bike, a forgotten junker that had a wooden dowel for an axle, mismatched wheels and a cardboard engine made from a Michelob Ultra 12 pack case. Like all projects though at Dime City, we look for the worst off machines as they have the least amount of chance in being picked up by someone and rebuilt given a second chance at life.
The build began with tearing what was left off of the bike discard the trash and items that were not usable and salvaging what could be. Items like the frame, hubs, triple trees and other main components were set aside for refurbishing while ancillary items like the bars, rusted fuel tank and cardboard engine were toss in favor of new hand-built items that would speak to the nature of speed we were aiming to achieve.
Our first step was rebuilding the frame and swing-arm so that they would withstand the rigors put forth by the massively over-built engine that would nestle between the rails. We removed the top center section of pressed and stamped steal and TIG welded and grafted in a new section 1.5″ chromoly tubing. When then used small elbow sections from old chromoly handlebars we had laying around the shop to gusset the mid and rear sections of the frame with a the final piece being a fully gusseted swing-arm limiting the flex the four hundred would have in the tight corners while the Bostrom Brothers tested her at Little Talladega Speedway for Season 2 of Cafe Racer TV.
After the frame modifications were complete we moved on to fitting the vintage replica Ducati race tank and fairing along with building one of our signature “Wasp” rear tail-sections complete with our closed-loop rear section of the frame where we use our tube bender with a custom die to make a perfect seamless loop which provides not only a quality visual but yields more strength and support. The final bodywork piece, the lower cowl, was crafted by a good friend and someone who always will be remember with his loss, Tom Petrovic by hand sculpted first from foam and then transfered to fiberglass and refined into what you see in the photos.
In looking to keep rolling weight to a minimum we opted for a quality set of shouldered aluminum rims laced up with Buchannan’s stainless steel spokes shod with a pair of Metzler rubbers ensure maximum grip on the pavement. On the front-end we compiled a myriad of parts from CB400F, CB450, CB750 and even a YZF 600 to achieve what we believe a stock dual disc setup should be represented as.
As for the engine, the heart of the machine, we chose the best parts available and went with a Yoshimura Black-box 466cc piston kit directly from Japan. We then worked with Kibbellwhite to manufacture valve train that would work in harmony with the Yoshi piston kit and custom Mega-Cycle CAM. The result, perfection at speed. As the Bostrom Brothers quoted, “It’s like a 2-stroke with a strong power band but the range of a 4-stroke.” As for the final sound, imagine a vintage Ferrari at Lemans rounding the first sharp corner and that’s a sampling of what this little track terror bellows from her custom exhaust. And to get power from the engine to the ground we used a set of Loaded Gun universal Cafe Racer rear-sets with our universal linkage kit. They afford quick shifting action and endless adjustability.
And last, but certainly not least, to keep the bike in sync with the corners and undulations on the straights we employed Progressive Suspensions new and at the time, never been installed on a vintage race bike, 970 model reservoir gas charged shock absorbers in combination with front internal coil springs. [They're actually marketed as for Harley Davidson's] Upon our initial test rides of the Four Hundred it was immediately recognized that the combination Progressive put together for us created a center-balanced and stunningly handling machine that could go from the road to the track without any concern.
The entire bike was safety wired to track specifications, the final paintwork was done by Bill Tribby with Liza doing the pin-striping for what we feel is a proper current day replica of what a factory works Honda 400F race bike would have been back in the mid-seventies.
Completed Photo album link here: http://www.dimecitycycles.com/gallery
Build Specifications:
1975 CB 400 Four Super Sport
Vintage Ducati Replica Race Fuel Tank & Fairing
Dime City Original Wasp Rear Seat Section
Dime City Original Lower Cowl Section
Modified Frame (Chromoly Backbone, Braces and DCC Rearsteel Loop)
Modified Swingarm (Chromoly Sections and Bracing)
BlackBox Yoshi 466 Piston Kit
Kibbellwhite Valve Train
Custom MAC/DCC Exhaust System
Progressive Suspension Front & Rear
Excel Shouldered Aluminum Rims w/ Metzler Rubber
Combination CB400F, CB450 & CB750 Front End w/ YZF Dual Discs
Loadedgun Rear Sets & DCC Linkage Kit
Keihin CR Race Carburetors
Tommaselli Clip-ons
Acewell gauge Unit
