Classic Motorcycle Build

Norton Commando Build

After sitting in storage for 20+ years, this old neglected Commando is getting a complete overhaul front to back.

1974 Norton Commando restoration

1974 Norton Commando progress to date

Norton Commando build

1974 Norton Commando as purchased

Is The Bike Worth It?

The Good Stuff - The frame is good, engine and frame numbers match, it has a clear title, and it came with boxes of original parts.

right side shift British motorcycle

Other Good Stuff - It's a low mileage bike, last registered 33 years ago. The speedometer and title show less than 10k miles.

The Bad Stuff - The front forks were badly pitted, and the only solution was to remove and replace the fork tubes.

remove fork tubes

Read: Front Fork Disassembly

vintage British motorcycle restoration

Read: Front Forks Overhaul

**********************

Cleaning Motorcycle Spokes

Both front and rear wheels had considerable rust built up on the rims and spokes. The heavy rust was removed with steel wool.

best way to clean rust from motorcycle spokes

During the front forks overhaul, the front wheel was propped up on the workbench and given a thorough cleaning.

best way to clean motorcycle spokes

After removing the brake rotor, each spoke and nipple was scrubbed with a scuff pad soaked in full-strength degreaser.

best way to clean motorcycle spokes

This was followed by rinsing with water, then back up on the workbench for a second cleaning, this time with a scuff pad soaked in half-strength degreaser, followed by rinsing with water.

install front wheel Norton Commando

**********************

Brake Caliper Overhaul

Fifty-year-old brake calipers do not come apart without a struggle. Since the bike had sat for decades, there was plenty of concern for the caliper pistons being stuck and corroded.

rebuild old motorcycle caliper

Before and After Caliper Overhaul

polished aluminum brake caliper

Read: Brake Caliper Overhaul

**********************

Other Bad Stuff - The internal exhaust threads in the cylinder head were stripped, which is not uncommon on Commandos, as the screw-in exhaust nuts often vibrate loose and damage the port threads.

stripped exhaust ports

So, another time-consuming repair was removing the cylinder head.

Repair or Replace Head?

I contacted Jim Comstock, a well-known Norton specialist. After looking at the pictures, he said that the fins and the exhaust threads were repairable, but he's back-logged with work for at least six months. I emailed several other places, but unfortunately, they don't have the same expertise as Jim does.

Plan "B" was to find a good replacement head. Either way, the old head had to be taken off.

Norton Commando cylinder head removal

Read: Norton Commando Cylinder Head Removal

**********************

After several weeks of sending inquiries to ebay sellers and classic bike specialists, I found a good used head on ebay.

Commando RH4 cylinder head

Upon disassembly, I found that the valve guides and seats were in very good condition. All the head needed was a good cleaning.

motorcycle cylinder head before cleaning

**********************

Cylinder Head Cleaning

In the Norton Workshop Manual, there's a section on how combustion chambers and exhaust ports accumulate carbon deposits, and caution must be given not to scratch the aluminum alloy material while cleaning. Do not use steel scrapers or a screwdriver blade!

"Old School" cylinder head cleaning fits my style and budget - degreaser in a spray bottle, brass cleaning brushes, a little Emery cloth, and a lot of scrubbing.

how to clean aluminum motorcycle cylinder head

Read: Clean Carbon Off Cylinder Head

This method takes longer than vapor blasting, but it's less expensive and gets the same results.

**********************

Cracked and Missing Fin Repair

Although several methods can be used, TIG welding is the most efficient way to weld cast-iron.

motorcycle cylinder repair

Read: Cracked Cooling Fin Repair

repairing broken cooling fins

***********************

Norton Commando Articles:

Brake Caliper Overhaul
Remove Fork Tubes
Front Fork Disassembly
How To Polish Motorcycle Forks
Norton Commando build
Front Fork Assembly
Cylinder Head Removal
Norton Commando Upgrades
Norton Commando History