The frame and fork of fixed gear bikes are not compatible to install disc brakes on them, because disc brakes are usually recommended for strong and firm frame bikes, but you will notice tubes and joints of tubes are not durable to absorb the sudden stopping power of disc brakes, fixie bikes are cheap as compared to MTB and road bikes, disc brakes setup is not a cheaper setup, you have to spend many bucks for this setup, frames of these bikes would easily break or crack from the joints and corners of tubes because disc brake is much more powerful brakes and also forks of fixie bikes do not support the braking power and capacity of disc brakes, aluminum and carbon fiber frames of fixie bikes are non-compatible with disc brakes, but if you have a steel frame and more durable fork then it is possible to install disc brakes on fixie bikes.
If you afford to buy a new fork, then it would be better to replace or interchange your current fixie fork with a more durable and firm fork that should be compatible and strong enough to work with the disc brakes. these brakes are usually not necessary for fixie or fixed-gear bikes, the reason is that these bikes are not used to ride for hard and aggressive trails, it is not possible to ride with these bikes on uphill and downhill terrains, because these would not support these trails, but if your downhill trails are not aggressive, and you are using your fixie bike on a daily and regular basis, then for DH trails it would be better to install disc brakes on your fixie.
There are specific and recommended forks for installing disc brakes with them, disc brake forks contain special two clamping holes where these brakes are mounted with the forks, there are two types of these clamps, flat mounts, and post mounts, so you have to look for these mounts in your fork, fixie bikes do not contain these mounts, you have to install that kind of fork which contain these mounts and also you have another option of welding, you can easily attach these mounts to make a room for the attachment of the disc brakes. disc brakes have two types of mounting systems,
- Center Lock and
- 6-Bolt Mounts
- You have to make all of these mounts of the disc brakes compatible with the clamping holes of the fixie fork for the compatible setup, otherwise, it would be not possible to install disc brakes in a fixed-gear bike.
Function Of Forces:
When you start riding your fixie bike with disc brakes, your bike speed goes on increasing, and when you pull the levers of your front disc brakes, then the stopping power and capacity of disc brakes would directly convert into rotating torque forces and these forces would start dissipating and spreading within in the spokes and front wheels, but you are forcing the wheel to stop its rotatory movement, now all of these forces would directly hit and forward towards the left leg of the front fork, in this way the left side of your fork is badly affected but forces would not transfer towards the right leg of the fork, you have to choose better more durable and strong fork if you are installing disk brakes in your fixie or fixed gear bike.
Hub Compatibility:
Fixie hubs are usually non-compatible with disc brakes, spacing of the fixie hubs is different which makes them non-compatible for disc brakes, but if you find better spacing and a compatible hub to install disc brakes on the other side of the fixed gear, then disc brakes would be easily installed but it is an expensive process, you have to buy a new hub and also make drivetrain of your fixie bike compatible for disc brakes.
Rotor And Wheel Compatibility:
Wheels of fixed-gear bikes are also non-compatible with the adjustment and mounting of rotors with them. it might cause trouble or problem with the rotors of disc brakes, we might say as you would need to buy a new rear wheel, the rocket science behind this point is that the wheels of fixed-gear bikes are non-compatible with disc brakes and rotors.
Rear Clamping Dropout Issue On Fixed Gear Bikes:
Fixie or fixed-gear bikes have horizontal dropouts, the main purpose of these dropouts is to keep and maintain the tensioning of the chain and also bring the rear wheel near the seat tube, you can easily maintain the positioning of the wheel on horizontal dropouts but this advantage is not fulfilled with vertical dropouts, if you are thinking about the disc brakes then disc brakes for rear wheels on fixed gear bikes are not recommended, the reason is that when you pull the levers of rear brakes, positioning of the rear wheel and also chain tensioning is badly affected due to the strong result of disc brakes.
Why Disc Brakes Are Installed On Fixie Or Fixed Gear Bikes?
The requirements and purpose of disc brakes on fixie bikes are usually needed for winter seasons and for those trails, streets, or roads where there are deep layers of snow, when you are commuting on snow or in rainy streets, your tires would start slipping and skidding on the road due to the speed of your bike, then you need brakes to decrease the speed of your fixie bike, and also if you are using your fixed gear bike/ fixie for downhill trails then disc brakes are installed, without these reasons disc brakes are usually not must and compulsory for these bikes.