A comprehensive guide on how to choose your MTB fork
The fork is one of the essential components of a moutain bike, both in terms of performance and comfort. Modern forks are designed to give you comfort over small shocks as well as big ones. A whole range of adjustments is available on mountain bike forks. High-speed rebound, low-speed rebound, compression speed, fork hardness, air volume, and many more for the most advanced models. Let's start by looking at their composition.
How a mountain bike fork works
The operation of a mountain bike fork is fairly straightforward: when compression occurs, two stanchions are inserted into the fork's lowers, protected by seals. On release, the stanchions move in the opposite direction, withdrawing from the lowers.
Forks come in a variety of forms: rigid, single-arm, single-T, double-Ts. They operate in different ways. Entry-level models are generally spring-loaded, while mid-range and top-of-the-range models use air and oil technology (to make them lighter).
Pivot, axle and caliper support
Another important variable is the diameter of the fork steerer tube. This should match the headset bushing on your frame and headset. You can dismantle your current fork to check the diameter of your steerer tube.
The three sizes of pivot
- - 1,5"-1"1/8 ; (Conical: 38.1mm to 28.6mm )
- - 1″1/8 ; 28.6mm
- - 1″1/5 ; 38.1mm
Conical pivots have become the norm in recent years, providing greater rigidity to the frame and fork crown, which are subject to very high stresses in this area.
Check the diameter of the wheel axle if you want to keep your wheel..
This axis can be :
- - 9 x 100mm
- - 15 x 100mm
- - 15 x 110mm
- - 20 x 100mm
- - 20 x 110mm
Finally, the compatibility of the braking system must also be checked. There are currently 3 mounting standards: International Standard (IS), Post-Mount (PM) and rim brakes (V-brake). Today, the market has almost fully adopted the IS and PM standards. However, some entry-level models can still be fitted with V-brakes.
Setting up a mountain bike fork
Fork adjustment increases tenfold as you move up the range. An entry-level fork will only offer to modify the spring stiffness in relation to the rider's weight, whereas higher-end models will offer to adjust rebound, compression or travel, for example.
On the top-of-the-range models, you'll find a rebound adjustment knob. This is the speed at which the fork decompresses. On tracks with little gradient or few broken sections, the rebound can be increased to maintain maximum speed and stability. On rougher trails and for more demanding riding, the rebound must be low to avoid being propelled over the front of the bike in the event of an impact.
Compression
The air forks allow very precise adjustments. Using a high-pressure pump, the cushioning can be adjusted to suit the rider's weight and preferences.
Lock
Some models also allow the fork to be locked to prevent it from working unnecessarily when climbing and degrading the rider's performance. Locking is done either directly on the handlebars or at the top of a stanchions.
Rebond
Some forks also offer trigger and rebound adjustment. On impact, the stanchions will sink and disengage more or less quickly from the forks.
Mountain bike forks to suit all riding styles
The key to success in choosing a fork lies in correctly defining its future use. Depending on how you're going to be riding your bike (downhill, enduro, all-mountain, cross-country), the travel distance won't be the same. Travel is the distance the fork between the crown and the arch. This distance is therefore greater or lesser depending on the model.
Downhill
For intensive downhill or freeride use, high travel (200mm) is required to ensure the rider is ideally comfortable going downhill and on uneven terrain.
Enduro
For enduro mountain bikes, less travel (150 to 180mm) will be more suitable, guaranteeing optimum comfort for the rider, without degrading performance when climbing.
All-Mountain
All-mountain bikes, halfway between Enduro and XC, are bikes with 120 to 150 mm of travel giving it very good capacity on rough paths and uphills.
Cross-Country
For cross-country or marathon use, a shorter travel (100 to 120mm) is preferable on slightly uneven terrain. The rider's performance will be preserved, as the fork is lighter than one with more travel.
How much travel for my bike:
Your bike frame is designed to accept a fork with a certain amount of travel. It is essential that you comply with the manufacturer's recommended travel to avoid damaging your frame. Bike geometries are designed to be perfectly compatible with the travel of a fork. So choose a fork with the same travel as your current one.
The biggest and best-known suspension brands offer forks specially designed for every type of mountain biking.
The diameter of the stanchions is generally a good indicator of which model to choose. Fox have even decided to name their forks after the diameter of the plungers to make it easier:
- - 32 : XC
- - 34 : XC - All mountain
- - 36 : All mountain - Enduro - Dirt
- - 38 : Enduro - Freeride
- - 40 : Freeride - Downhill
