Dirt Jump / Urban Mountain Bikes

Typical Dirt Jumping Mountain Bike

Things to Look for in a Dirt Jumping Mountain Bike

• Fork: For dirt jumping, it’s very important to get a strong fork that can withstand a lot of abuse. As a test, approach the bike from the front and pinch the wheel between your legs. Grab the bars and turn them side to side a few times. A flexible fork (one that you can see twisting) should be avoided.
• Chain Retention: If the bike is single-speed, make sure that there is some sort of chain tensioner on the dropouts. Horizontal dropouts with a bolt-on rear axle are the best for single-speed dirt jumpers. If the bike has gears, make sure that it has a chainguide on the front sprocket. Losing a chain while dirt jumping never ends well.
• Wheels: Wheels take a beating when dirt jumping, especially when you are first learning how to jump, or when you’re learning new tricks. Because of this, look for wheels that have 36 spokes and always run at least 45 psi in your tires.
• Tires: Tires with small knobs or smooth tread patterns are preferred for dirt jumping and skatepark use. They roll faster, making jump sets easier.

Dirt Jumping Mountain Bike Frame Sizes

The most common way to size a dirt jump bike is the horizontal distance between the center of the head tube and the center of the seat tube. This measure is called 'effective top tube length' and sometimes 'horizontal top tube length'. The taller you are, the longer the top tube you’ll want. In general, riders more than 5’11” tall ride large dirt jump frames.

Most manufacturers provide suggested sizing charts, and because models vary so much between categories, we recommend searching for the chart specific to the bike you’re interested in. It’s important to note that everyone has different riding preferences, so it’s best to test out a variety of sizes before making a final decision.

Dirt Jumping Mountain Bike Frame Materials

The overall feel of a bike is largely dependent on what material(s) the frame is made of, so this is an important consideration.

Aluminum - Aluminum is light, stiff, and affordable, making it the most commonly used frame material. Because it is so stiff, aluminum bikes are characterized by a slightly rougher ride than those made from chromoly or titanium.

Chromoly Steel - Chromoly (a steel alloy) is lighter than high-tensile steel, strong, responsive, and offers a relatively supple ride. However, it is heaver than aluminum, carbon, and titanium.

How Much to Spend

Deciding how much to spend is a tough decision. As a general rule, the more you spend the better bike you get. There will be major difference between a $900 bike and a $2500 bike. In general, the more expensive a bike is, the more durable it will be (at least until you start getting into the high-end where lightweight construction may reduce durability) and the better components will perform. If you’ll be riding regularly, we recommend spending at least $900 on a dirt jumping bike. Anything less and you’ll be constantly repairing the bike and replacing components. If you’re a first-time buyer, you may be tempted to purchase a low-end bike and later upgrade the components as necessary. Know that it is often much cheaper to buy the components on the bike in the first place than it is to buy components later and upgrade.

For comparison, the three bikes below are priced at $550, $900, and $1600, respectively.

Scott Voltage YZ 20

• Price: $550
• Voltage C-Frame
• Vertical Dropouts
• Low-end parts
• 3x9 gearing
• Weight: 31.50 pounds

Scott Voltage YZ 0.1

• Price: $900
• Voltage B-Frame
• Horizontal Dropouts
• Mid-grade parts
• Single-speed gearing
• Weight: 29.07 pounds

Scott Voltage YZ TMO

• Price: $1600
• Voltage A-Frame
• Horizontal Dropouts
• Mid-grade and some high-end parts
• Single-speed gearing
• Weight: 27.75 pounds

Product Reviews

Be sure to do your research and read product reviews. Reviews are a great way to find out specifics about a particular model of mountain bike, user impressions, and things to watch out for or to upgrade right off the bat. After you’ve purchased a bike and had enough time to thoroughly test it, we encourage you to leave a review for other people to see when they are researching bikes on the web.

We hope you’ve found this information to be helpful. If you have a question that isn’t answered in this guide, our mountain bike forums are a great place to get advice from knowledgeable riders. Your local bike shop is also a great resource and the best place to test ride bikes before making a final decision.

Still need help choosing the right type of bike? View our general Mountain Bike Buyer’s Guide.