HONDA CB750 SPIDER
HONDA CB750 SEVEN FIFTY RC42
"This is how this Honda became the most beautiful cafe racer in the world" - AutoBild.de
PHOTOS & VIDEO
PURE RACER DNA, OUTSTANDING DESIGN
ABOUT THE PROJECT
Before we start. Feel free to share this project, photos, and videos but please tag our FB profile once you publish the content. Now here is the part for the least patient ;-)
Q: Is it for sale? How much is it?
A: The bike will available for sale 2021 in an unchanged condition. Contact us for pricing and details.
Q: Can you make the exact copy of the bike? or a cafe racer for me?
A: Yes. Contact us for pricing and details.
If we could build this motorcycle again, we wouldn’t change a single thing. It took us 5 months to design and build The Spider. This could be faster as COVID-19 slowed down some parts delivery but on the other hand - we ware not in the hurry with this project. Time was less important. The key was to follow ideal geometry, design, and performance balance with top quality manufacturing.
Spider was design and developed in Poland close to Warsaw at KrisBiker CustomMotorcycle Garage.
We took Honda CB750 RC42 as a base for this project. Then we have study hundreds of cafe racers project pictures as examples to follow. Soon all the pictures we have stuck on our project wall become the list of thinks we aim to make better. Much better, but knowing the limitations that are natural for any project.
The question was: do we want to develop another black cafe racer? or retro design cafe? "Racer" - historically that was the main mission of the cafe racers so how about we play with sport design?
That was the moment when we say goodbye to Honda's most natural color – red. There was only one condition. We need to keep a 100% straight line between the seat and the tank. And that was a second goodbye - with original Honda Seven Fifty tank.
Honda CB750 Four tanks had that beautiful clear and simple line we wanted to achieve but we could not find any good condition and fair price CB750 Four tank in Poland. We ware very lucky to find a perfect condition 1976 Honda CB 550F tank with the same strait and clear bottom line we needed. Now. The color. Imagine two guys discussing "yellow"? You will have the range between lemon and orange and both will mean yellow :-) We don't know the name of the color we came up with :-) it's a custom made a modification of Ducati and Bumblebee Camaro with Honda S600 logo.
THE ENGINE & FRAME
The engine of course is Honda CB750 Seven Fifty but it was completely restored (new OEM piston rings, cylinder head full-service inc. surface grinding, cylinder honing, valves service, piston clearance verification, engine starter renovation, carburetor ultrasonic cleaning and balance check etc). We gave it a mix design of satin cylinders and wrinkle engine covers and body.
The seat and tail section was modified (lowered and shortened). There are some geometric requirements for cafe racer you need to follow. Even if we have interpreted some of them to our vision - the line of the tank and seat was the most important condition. In order to achieve the most hygienic and clear line of the rear section, we have also cut the passenger footpegs mount and central stand.
All the elements cut from the frame reduced the weight by 4 kg.
Front forks converted form GSXR 600 K6 with custom made top tree and axis as the original Honda CB750 was too long and too thin. New dust and oil seals with fresh fork oil. Brand new rear dampers are 15mm shorter form OEM. Seven Fifty Originally is a touring motorcycle. In order to meet our goal of sport design, we needed to lower the bike. We knew that the front tire will be massive, we knew that the rear section will be lower, we knew that forks will be shorter. Calculating the perfect horizontal line of the tank and seat to the ground was not an easy exercise. Especially if we had no wheels at this stage ;-)
GSXR 1000 front brake calipers with new Brembo brake pads. New, impressive 318mm Italian Braking disks (floating) required small adapters with longer bolts. Why? We had to align to wheel hub but let's dop the wheels for the moment. Front Hell steel hoses and custom made steel hose for the rear calipers. The rear brake caliper is restored Honda CBX750 RC17 caliper with wheel and frame mount equipped with a new Braking disc. Rear OEM brakes pump was replaced with a new "slim design" pump with an integrated brake fluid reservoir.
There was a huge argue between us regarding the headlights. Should we use a classic cafe racer approach or to take a risk with something new. The inspiration came when we saw the BMW K100 cafe from Lithuania. That was it! Yamaha MT-03 new headlight! gave a crouched, sport look of the whole motorcycle. New integrated (homologated) turn signals and daylights just below the headlight. Next was the rear lights. An outdated seat integrated led lamp was not the option. Small LED diodes were not the option too. Both solutions are present in almost every cafe racers project but we did not see any project with vertical lights so let's take a risk. And we are very glad about the effect. We have fully homologated stop, turn and daylights mounted and aligned with the geometric line of dampers.
The biggest challenge of the project. The Spoked wheels ware the first thing we decided to use in the project but they consumed one month on research and development. There are no accessory spoked wheels available on the market for Honda Seven Fifty especially if we converted the front suspension. You are looking at 17" Excel rims that ware incorporated on modified hubs form Honda Comstar wheels. The wheels ware custom developed by our dear friend Nazar form Gazzz Garage (Kiev) and it was his great effort and contribution to the project. We had to meet GSXR front forks conversion requirements, hubs wide, front brake disks size, and rear OEM swing arm. All of that was not an easy exercise. Wheels are supported with Supersprox rear sprocket (aluminum with steel teeth) +4 teeth that required a stronger and longer chain (DID 525 VX3). Front tire Pirelli Night Dragon 130/80R, rear tire Pirelli Night Dragon 160/70R with custom-developed side letters.
We are now calculating all performance indicators. The bike is much lighter as you can imagine. The factory dry weight of 215kg was reduced to 194kg. We have rear sprocket with 44 teeth instead of 40 OEM. This gear ratio increases torque and provides +3,1% acceleration. Polished carb air intake will improve airflow. Sport silencer and improved exhaust heat flow should provide aprox. +2-3hp or spider power ;-). All that combined with -21kg of weight increase the performance but again we are in the process of calculating that. Wheels rotation weight also changed but it's very difficult to measure.
Accel clip-on handlebars with Barracuda grips, custom mirrors, and KOSO digital speedometer (db-01rn) all brand new. 4in1 exhaust manifold with new G.P.R silencer (M3 E4 homologation) custom-designed rear sets and new battery - hidden so even we forgot where is it ;-)
Feel free to share the story
Photo session: Łukasz Widziszowski
Video production: Emil Sobczak
Special thanks to:
Gazzz Garage, Aerografix, Felg Styl, Farys SC, Dixer Parts, Tire Letters Poland, Łukasz Kondracki, Centrum Praskie Koneser, Moto wydech,