Today's best carbon composite front forks (often called "carbon fiber front forks") weigh on average about one-third of steel forks and half of aluminum forks. Therefore, it is no wonder that the proportion of front forks you see in mass-produced bicycles and aftermarkets is getting higher and higher, and they are all made of carbon. Compared with installing lighter wheels, installing carbon fiber front forks has less impact on bicycle performance, but weight reduction will definitely have a significant impact.

Forks Explained

Fork offset or fork, and trailing offset are the distance that the front fork blades are bent forward with respect to the vertical line of the front fork servo. This number is sometimes printed on the front fork servo label. Most forks have an offset of 4.3 cm, but some are 4.0, 4.5 or even 5 cm. Trail is a combined calculation of frame head angle and offset. A long path is good for stability, while a short path makes it more responsive. But on most of the performance-oriented bicycles we tested, the head tube angle is 73 to 74 degrees, and installing a front fork with an offset of 0.2 cm long or short instead of the original fork has no effect on handling.

Fork length, measured from the bottom of the crown ring to the end of the fork. There is not much difference between the road forks, only 3 mm. Audax, commuter and travel forks can vary between 10-18 mm. When replacing the fork, make sure that the length of the new fork is the same as the fork to be replaced

Fork Types and Sizes

100% carbon forks

They are usually manufactured using a single, uninterrupted molding method. Although the cost is about twice that, they are about 40% lighter than the cheaper "carbon/aluminum/carbon" and are resistant to accident damage. Stronger-see below.

Carbon/alu/carbon forks

These use carbon fiber front fork blades and steerers attached to the aluminum crown.

Carbon/alu forks

The cheapest type of carbon fork described here is "carbon/aluminum", where the carbon fork blade is glued to the aluminum crown and steerer tube.

Integrated fork crown

On bicycles, it is identified by a very small gap between the front fork crown and the frame. Used for frames suitable for integrated or built-in headphones.

Non-integrated fork crown

The earphone cover is clearly visible between the frame and the fork crown. It is used to fit the frame of ordinary earphone cover.

Steer tube size Most modern frames use a steerer tube with a diameter of 1 1/8 inch. Older frames may require a 1-inch steerer.

Wedge Bung

Wedge plug, star nut or star washer? Some front forks are equipped with a plug that is inserted into the steerer tube to preload the head tube bearing. These plugs are aluminum internal expansion plugs with a central 6 mm thread. Various sizes are available in the aftermarket to suit the inner diameter of the rudder tube. They should always be used for carbon front fork steer tubes, not star washers (or star nuts)-star washers may damage the carbon fiber when forcibly inserted into the steerer tube. However, star washers are suitable for forks with aluminum or steel rudder tubes.

Brake Bolts

The depth of the fork crown varies from brand to brand, so it is worth checking whether the Allen wrench joint nut that enters the rear of the fork crown is long enough-see it rotate at least five Allen key turns on the threads of the caliper center bolt. Fortunately, the two tested forks were deeper than the average fork crown and provided long hex nuts, although longer or shorter hex nuts are needed and can be easily purchased from bicycle stores.

Fork Blades

The front fork blade connects your front wheel hub to the rest of the bike. Some shapes are to improve aerodynamics.

Material

The carbon composite front fork used in road racing consists of pre-impregnated carbon plates. They are layered in such a way that the design engineer can adjust the amount of deflection so that it hardens significantly at the end of the stroke, just like a steel fork. The lower cost carbon forks use aluminum crowns or aluminum crowns and steering tubes.

Dropouts

The trip can be formed as a part of the molded part itself, or as an alloy part joined to the tip of the front fork blade. The safety label meets many international legal requirements to prevent the wheel from falling when the fork is loose.

Fork Crown

The crown connects the blades with the rudder tube and provides a seat for the crown of the headset.

Steerer Tube

It is allowed to install the inner ring of the earphone bearing and the pipe of the handlebar.

Cutting the Steerer Tube

Most forks are equipped with a steering tube with a length of approximately 300 mm. These need to be trimmed with a hacksaw to fit the handlebar height that the user likes. Before deciding how much to trim from the steerer tube, be sure to install the earphones and slide the steerer tube over the head tube. We recommend leaving a steerer tube of at least 30 mm extending from the top edge of the headphone cover so that the handlebar height can be changed in the future. Always use a dust mask when cutting carbon fiber steerer tubes; this will protect you from inhaling any harmful particles.