The key factors to consider when deciding between rim or disc brakes for your road bike!
Although it’s only been a few years since major manufacturers started producing road bikes with disc brakes, they’re now being produced in similar volumes to their rim brake cousins.
There are a lot of factors to consider when purchasing your next bike, and now, it’s not just about frame materials, geometries, and colours, but also the type of brakes you’re going to use.
Here’s some of the key factors to consider when thinking about brakes!
Firstly, how do both types of brake work?
Rim Brake: Rim brakes do what they say on the tin – small calipers are mounted to the frame, and these apply pressure to the rim of the wheel. The caliper is controlled via the use of cables running from your brake levers, along the frame, and to the brake. The pads used are a type of hardened rubber compound.
Disc Brake: Disc brakes work by applying force to a metal rotor attached to the hub of your wheel, with the force applied by a frame-mounted caliper. The majority of disc brakes are operated hydraulically, via a non-compressible fluid in the cables connecting the brake with the brake lever.
The factors to consider when deciding what type of brake is for you:
Power and modulation
The braking force achievable with a disc brake bike far exceeds that of a rim setup. The power of disc braking is what’s made it the mainstay in off-road bikes.
Furthermore, the modulation offered by disc brakes exceeds that of rim brakes. ‘Modulation’ refers to how easy it is to control the braking force. As disc brakes apply force in a linear manner thanks to the use of fluid in the cables, it’s easier to control the braking performance than the exponential nature of the force applied by a brake caliper.
The upshot: If you’re a heavier rider, having the power of disc braking is an advantage. The superior modulation of discs also makes them well-suited to someone who may be doing a lot of riding in the mountains, where there are long, technical descents.
Rim brake frames are typically lighter than those built for disc brakes. This is because disc brake frames require extra strength in the fork and frame to withstand the braking power that is achievable. And likewise, disc brake wheels are heavier due to the addition of the rotor.
The upshot: If you’re looking for a bike that’s all about saving grams, then you may want to get rim brakes.
Rim brake bikes are super-easy to maintain. They can be adjusted by varying the tension in the cables, something that is easily done with a tool such as our 8 in 1 Multi Tool or Mini Ratchet Toolset, and swapping out the pads is also super easy.
Disc brakes are a little trickier to maintain. Disc brakes occasionally require ‘bleeding’, which is where the cables are purged of any air bubbles within the fluid. These bubbles affect the smoothness of the braking that is achievable. ‘Bleeding’ needs a set of special equipment, and while it’s not the toughest of processes to carry out, it’s not as straightforward as rim brake maintenance.
The upshot: While disc brake maintenance isn’t straightforward, performing a bleed shouldn’t be required too frequently, and you shouldn’t make it an obstacle to your next bike being equipped with discs.
One key thing when making your decision between rim and disc brakes is compatibility.
If you have a garage full of old bikes that you still use, they’re likely to be rim brake frames. Unfortunately, you cannot use disc brake wheels on rim brake bikes and vice versa, and it’s not possible to retrospectively modify a rim brake frame to make it able to work with discs due to the structural differences required in disc brake frames.
So, if you’ve got a load of rim brake bikes, all those wheels you have aren’t going to be compatible with a new disc brake bike.
The upshot: If you’ve got some new of super-fancy rim brake wheels you want to be able to swap onto your new bike, you’re going to have to make sure you choose a rim brake set up.
If you’re buying your new road bike to be a winter training bike, you’re probably better off going for discs. Their superior stopping power means they’re great for if the roads are wet or icy. However, do remember, the limit to the stopping power of a bike is actually the tyre’s traction on the road – if you lock the wheels and start to skid, there’s no stopping you!
Also, roads tend to be muckier during winter due to wind and rain bringing mud off the surrounding fields and verges. Mud can quite easily get gummed up in your rim brake caliper and can impact the braking performance, whereas this situation doesn’t apply to discs.
The upshot: Looking for a winter bike, or one that will be used in harsh weather? Go with discs.
Frames built for disc brake bikes have a lot more frame clearance – that is, the space available at the fork and seat tube for tyres. This is because there is no need for the frame to be near the wheel for mounting a caliper, as there is with rim brakes.
The result of this is that you can run big beefy tyres on a disc brake road bike – typically up to 32mm, whereas on a rim brake frame you’ll be lucky to squeeze in even a 28mm tyre. The advantage of fatter tyres is the superior grip and lower pressures that they can be run at.
The upshot: If you’re wanting to run particularly wide tyres, say for a winter bike, go for disc brakes. However, some rim brake frames can tolerate 28mm tyres, so if that’s wide enough for you, a rim brake bike isn’t out of the question – just check that you’ve got enough clearance before you buy!