What Is A Derby Cover On A Harley-Davidson And Are They All The Same Size?

Harley-Davidson is one of the biggest, most influential major motorcycle brands in the world. In the United States, the Wisconsin-based company holds a market share of approximately 27%, making it the country's No. 1 motorcycle manufacturer.

Harley-Davidsons produce a unique sound and have a powerful presence on the road, so even if you've never owned or ridden one, you could probably spot one from a mile away. Distinctive design elements, such as derby covers, also contribute to Harley's legendary status. 

But what exactly is a Harley-Davidson derby cover, and why is it referred to as a derby cover in the first place? Do derby covers serve a function beyond just aesthetics, and what is their significance in the motorcycle space? What types of Harley-Davidson derby covers are available, and are they all the same size? Here's what you need to know about derby covers and their role in Harley-Davidson design.

Derby covers protect a motorcycle's clutch from dust, moisture, and debris. They are typically found on the left side of Harley-Davidson motorcycles.

Contrary to popular belief, the term "derby cover" has nothing to do with the Kentucky Derby, or horse racing at all. The name comes from the initial design of Harley-Davidson clutch covers, which resembled a derby hat. Also known as bowler hats or coke hats, derbies are rounded hats with narrow brims that were popular in the late 19th and early 20th centuries — Charlie Chaplin famously wore one as part of his Tramp character's costume.

While derby covers play an important role in protecting the clutch from damage, that's not all they are for. They also serve an aesthetic purpose, adding to the experience of owning and riding a Harley-Davidson. With prices for new Harley derby covers ranging from approximately $50 to $195, they offer a great way to add a personalized touch to a bike without spending a fortune or making major modifications. 

Harley Davidson derby covers are not all the same size. A cover's size is primarily determined by the number of mounting holes. If you own a Harley-Davidson with three, four, or six holes, then you likely won't have a hard time choosing the right cover, as each comes in just one size.

It's a bit more complicated with five-hole derby covers, which come in three sizes. This is not too much of an issue, however, since you need to know your motorcycle's year and model to ensure you purchase the correct cover anyway.

If you want to see what derby covers Harley-Davidson offers for your motorcycle, visit Harley's online store and navigate to the "derby covers" section. Near the top of the screen, you should find two drop-down menus where you can select the year and model. Let's say you own a 2024 Harley-Davidson Street Bob 114. Select "2024" from the first drop-down menu, and "Street Bob 114" from the second — you'll see about two dozen five-hole derby covers compatible with your bike.