Tech Tips

Welcome to the mysterious world of wrenching. So you weren't born with a silver wrench in your mouth? No idea, how to tell a metric nut from an SAE bolt? No clue about torque settings, drain plugs or hex keys? Don't despair, here's a few basic mini tutorials to keep your sled rolling.

How H-D vehicle identification numbers work, and how to decode them.
To understand vehicle identification numbers (VIN) is crucial when buying an old Harley. It’s the only way to check if the papers belong to the bike and vice versa, and a lot of trouble and heartache can be avoided by doing so.
The VIN is the basis to set out from when shopping for spares and when researching parts in old parts catalogs. As the system has changed a couple of times in the last 117 years, we provide an overview.

Here's a few vital measurements of popular H-D engines.

Get the right amount of fluids into your engine, gearbox or forks.

Find the right size tires with these three different measurement systems.

Some data to SAE threads.

Use this table to easily convert millimeters into fractions of inches or decimal inches.
Convert the fractional number after the hyphen to a decimal, i.e. divide numerator by denominator (see chart) ... 11 by 64 = 0.171875, Replace the zero of the intermediary result with the integer of your basis ... thus 0.171875 becomes 3.171875., To convert in millimeters (centimeters) mulitply this inch-decimal by 25,4 (2,54): 3.171875 x 25,4 = 80,566 mm,

Convert volume, temperature, pressure, weight etc between metric and US systems.