How to Build a Cafe Racer.
Clubman 'Cafe' bars
Cafe Racers, and an unpopular opinion.
Shoot the messenger.
It's ok with me.
I'm sure most of you are familiar with the 'reality' TV show, “Orange County Choppers”. A “reality” show with a family business that makes choppers with lots of drama and fights and dumb crap.
Let's start at the beginning.
Way, way back in the day, there were no real 'go fast' parts readily available. You couldn't go to ebay or any of the thousands of online stores for hi-po parts.
So people removed weight. They stripped off everything they could. This made the bike accelerate faster, stop sooner, and handle better.
The original bobbers and choppers were born.
They looked the way they did because of what they did.
Simply, FORM FOLLOWS FUNCTION.
Later, in the late 60's and 70's, choppers got a little more 'artsy'. Most of those had lower seating and raked front ends. It's not surprising, though, that most of those were ridden by people who rode long distances, and the prevailing ergonomic ideas at the time said that a reclined position was best for prolonged riding, and suspension tech available for the big twins at the time being what it was, a raked front end was, in fact, better for straight-line high speed stability.
So in a way, form followed function for these, too.
OCC and companies like them butchered and perverted the idea behind bobbers and choppers. They took some of the aesthetic cues from these and made 700lb behemoths that couldn't stop, turn, or really go very well. The media sold us a cake made of cardboard and told us it tasted great and was the real thing.
In Europe, where motorcycle road racing really started, there were many bikes that civilians could choose from.
They did what they could to make them faster. Reduced weight, upgraded suspension, and a riding position that lent itself well to going fast.
They built road-legal race bikes.
And they did race. They raced from place to place, at club meet-ups on tracks, and some became privateers.
The bikes looked like they did because of what they did. The bikes were racers.
They met at cafes, among other places.
Again, this is a form follows function situation.
You want to build a cafe racer?
Then begin at the beginning.
Many of my friends have heard me say “safety third!”, but they know I'm joking.
You have a thirty or forty year old bike. Before you do anything, do these things:
Check your brake system. Rebuild everything as needed.
Make sure all of your controls are working well. Throttle, clutch, gear shift, and steering bearings all need to be smooth and in good working order.
Your suspension is ancient and worn out. Spring for the 300 dollars for good upgraded suspension. New springs up front and new shocks. Hagon and Progressive make very good stuff at a reasonable price. Ikon makes 80's and 90's race-tech stuff for a little more. Works makes very high end stuff for your vintage bike at a premium. Replace your wheel bearings. 9 times out of 10, they need it.
You need good tires. Period. I've been very pleasantly surprised by Shinko tires. Great grip, good wet and gravel performance, and very reasonable cost. Of course, Avon, Dunlop, IRC and all the other well known brands can be had for more, and are all quite good.
You need to do a complete tune-up. Valve clearances, oil, air filter, proper jetting if you've made changes to the intake and/or exhaust. Points, ignition timing, all that good stuff.
All of these things will make you quite a bit faster than you might think.
Once these are done, move forward.
Your engine is tired.
It's making 20 to 40 percent less power than it was when it came off the showroom floor. A simple hone and re-ring job, along with valve lapping (along with valve seal replacement) will go a long way to getting a lot of that power back.
High mileage motors often go oval. Going next size over pistons, rings, and a bore and hone will get you back to 100%, and then just a tad more.
Companies like bore-tech make 1.0 and 1.5mm over pistons and rings for cb350's with deep valve reliefs for very reasonable prices. Other companies do similar things for other bikes.
Replace your chain and sprockets. Worn chains and sprockets can rob you of 3 or 4 horsepower at the rear wheel.
There are a lot of tricks to make certain bikes make more power for little or no money. K4, K5 and K6 SOHC4 cb750's could be brought back near K0 and K1 horsepower figures by modifying the advance unit, removing the cam dowels, rejetting and a few other minor mods. Find out what is available for your bike in this area.
Lighten your bike any way possible, while maintaining safety.
Smaller batteries, removal of un-needed parts, aluminum tanks, lighter seats, aluminum rims, smaller gauges and lights, a lighter aftermarket exhaust.. the list goes on.
Now, your bike is even faster. And safe.
Still want to go faster?
Now is the time to change your seating position. Clip-ons (or properly sized clubmans) and rearsets.
Now you have a street legal race bike. With the removal of lights, the appropriate bits safety wired, and an oil pan, you could, if you wanted, go race in many vintage categories.
This is a 'Cafe Racer'. And it looks like one because of what it does.
Or should we start “Orange County Cafe”? We wouldn't even have to change the logo.
A properly setup Cafe Racer
In the image above:
1. A front fender is useful for two reasons on a road bike: To keep water and gravel being flung up to the engine, and to help stabilize and equalize the front forks.
2. Any time changes are made to the intake, such as removal of the stock airbox in favor of pods or velocity stacks, the jetting must be changed to ensure proper fuel-to-air ratio.
3. On Mr. Johnsons' bike, the entire top end was rebuilt, all the seals replaced, valves adjusted properly and ground, valve guides were tested to be in spec, and a cam with a streetable, reasonable bump in lift and duration was installed.
4. The cylinders were honed and checked for roundness, and new rings were installed on the pistons for proper compression and power.
5. This bike received a new stator, a solid-state regulator and rectifier, replacement of various parts of the wiring harness, new points, and a lightweight battery.The starter was also replaced, and a low-draw, high output HID was fitted for the low beam. Multiple grounds were connected to both engine and frame.
6. A larger oil pan was fit to aid in cooling and lubrication for an engine that is a bit higher strung and will ran a tad hotter than stock.
7. New, high quality all-weather street tires, properly sized and balanced, were installed on this bike for safety and performance.
8. With the removal of the stock airbox and stock inner fender for the "open triangle" look, a lightweight aluminum inner fender was fabricated to keep rocks and water from being flung at the carburetors and electronics under the seat.
9. Rear suspension was replaced with new Progressive brand suspension. Front suspension was resealed, serviced and adjusted.
10. For safe, relatively comfortable spirited riding, rearsets are a must with lowered bars, whether they are clubmans or clip-ons. In the case of this bike, Mr. Johnson was measured, while on the bike, to determine proper placement. This is largely overlooked by many builders.
11. The brake master was rebuilt, as was the caliper, with a new piston. New stainless lines were installed as well. The rear drum was checked, pads replaced and adjusted. Braking is important!
Not shown on the picture is chain and sprocket replacement, control service and replacement, petcock and fuel line service and replacement, testing of coils and all other electrical components, spoke replacement and truing of the wheels.
Additional Work and Improvements
Not listed above are these additions:
- The subframe is boxed with plate steel on two planes
- The velocity stacks are screened at the carb bellmouth
- Cornering clearance improved with the new exhaust
- The signal lights, while recessed, are very bright and visible
- The new stainless steel front brake line is long enough that it will not be stressed at complete fork extension even if the forks are moved all the way back up through the triple clamps
Cafe Racer Build Parody
Ichiban Motos Cafe Parody
Recently, Ichiban Moto began making a video blog parody of many "cafe racer" builds that have been so prevalent on various cafe racer forums around the web.
While his mods are over-the-top for the sake of comedy, they are not far off from many "builds" out there.
This particular "build" just uses all the terrible ideas and modifications on a single bike.
I suggest you watch all of them, enjoy yourself if you already understand that this is a parody, and take notes on what not to do if you don't.
They can be found at his youtube channel, located here.