CBX Reborn: Honda “CBX1147” Café Racer

Family Heirloom, Transformed: 1147cc CBX from Laurent Heraux x JDMAX… 

As far as production motorcycle engines go, few can claim the mystique, visual presence, and soundtrack of Honda’s six-cylinder CBX1000 engine. The 1047cc “slant six” boasted dual overhead cams with eight bearings each, 24 valves, and a maximum output of 105 howling horses.

But it was less the outright performance than the very idea of the CBX that made it an instant icon.

“Just as the 1969 CB750-four resonated with public respect for all the races won by Honda fours, so the six ignited a helpless attraction to CBX because it had six cylinders like Hailwood’s winning bikes. It was unique. That attraction, for some of us, persists undiminished to this day in the form of cherished hulks (“I’ll never sell that thing…”), restorations, and extremely various customs…” -Kevin Cameron, Cycle World

“Extremely various customs” is right — we’ve featured quite a heady array of CBX customs over the years. What makes the CBX1000 so compelling for customizers is that the incredible powerplant was stuffed into a chassis that was inadequate for its size, weight, and power.

This was an issue with many of the late 70s to early 80s superbikes — so much so that the AMA Superbike Championship of the era has been called the “vintage weave derby” — but the weave was especially pronounced in the CBX. Fortunately, much can be done with modern suspension and tire technology to bring the bike’s handling and braking more in line with the engine.

Enter our new friend Laurent Heraux, an aerospace professional whose father owned this ’79 CBX1000 for 45 years.

“He gave it to me 4 years ago to be able to do this project precisely. The bike was no longer running and I undertook to put it back on the road by turning it into a modern café racer.”

To help him with the build, Laurent sought out the French workshop JDMAX Motors, builders (and racers) of some of the baddest CBX customs on the planet. They split the work between them, with JDMAX handling the lion’s share of the frame modification, engine rebuild, and adaptation of modern running gear. Laurent, meanwhile, took care of the exhaust, aesthetics, upholstery, and paintwork.

A pair of Aprilia superbikes would lend their hardware to the CBX. The bike sports a set of inverted front forks from an Aprilia RSV1000R, while the swingarm, brakes, and wheels come from an RSV4 of the same brand. Talk about a serious upgrade in terms of suspension, brakes, and available tires. Meanwhile the alternator is from a Kawasaki ZX-7R, and the controls come courtesy of a Yamaha R1. 

Then there’s the engine, which JDMAX rebuilt from the ground up with lots of internal work. Says Laurent:

“The engine has been fully prepared, the crankshaft lightened, the connecting rods balanced, and the engine is 1147cc instead of 1047cc…”

The engine is still in the break-in period, but Laurent says the bike is already a pleasure to ride. We can only imagine how glorious it will be to open the taps fully, loosing the high-rpm six-cylinder symphony of that reworked engine. But Laurent is most proud of resurrecting his family’s old non-running motorcycle and transforming it into such an incredible work of kinetic art:

“The greatest pleasure in this project was to see my parents love the project as much as I do.”

Good on you, Laurent — you’ve done them proud! Below is our full interview with Laurent about the build for those who want to go a bit deeper into the details.

Honda CBX Custom: Builder Interview

• Please tell us a bit about yourself, your history with motorcycles, and your workshop.

So I’m Laurent, 38 years old, passionate about motorbikes thanks to my father. I ride a 2008 R1, CBX, and a 1100 GSX-R turbo is in progress.

The CBX comes from my father who has owned it for 45 years; he gave it to me 4 years ago to be able to do this project precisely. The bike was no longer running and I undertook to put it back on the road by turning it into a modern café racer.

I don’t work in the world of motorbikes but in the aeronautics world, I just have a workshop at home for my personal pleasure.

• Why was this bike built?

Personal and sentimental project this bike.

• What was the design concept and what influenced the build?

As for the idea of ​​this project, for a very long time I always wanted to have an extraordinary CBX,  and 10 years ago a French preparer had made one in this style (JDMAX).

He is also the one who took care of the biggest part of this project: frame modification, adaptation of modern running gear, refurbishment and preparation of engine and electrical harnesses.

For my part, I took care of the exhaust, aesthetics, upholstery and painting.

• What custom work was done to the bike?

Everything is custom-made and improved. There are very few original parts left because the engine is prepared, the crankshaft is lightened, the connecting rod is balanced, the engine is 1147cc instead of 1047cc, and there’s the Motogadget speedometer and carbon parts.

• RSV1000R front fork
• RSV4 RF swingarm
• Tuono Factory shock absorber
• RSV4 rims
• RSV4 brakes
• ZX7R alternator
• R1 Switchgear

 

• Any idea of weight or horsepower?

Originally the CBX weighs around 270kg for 105hp, now it must weigh 200kg for 135hp, which is not very powerful but magical to ride with the 6 cylinders.

• Can you tell us what it’s like to ride the finished bike?

Currently the running-in is in progress because it was recently finished, but it is already a real pleasure to ride.

• Was there anything done during this build that you are particularly proud of?

The greatest pleasure in this project was to see my parents love the project as much as I do.

This project was started 4 years ago and already some ideas for improvement such as OZ rims and FC carburetors are coming up.

Follow the Builder: @l0r3nt_ro