Since their rise to popularity in the early 2010s, disc brakes on road bikes have been making waves. So wildly different from their rim brake alternative in performance, design and feel, it’s hard not to draw comparisons between the two and almost everyone has an opinion.
While disc brakes boast a whole host of performance advantages, maintenance, cost and compatibility are all other important factors to consider.
To understand where we are now, here’s some historical context: rim brakes were the be all and end all of braking until the introduction of the first disc brakes in the 1970s, which had originally only been used on cars and motorbikes.
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Mountain biking terrain was becoming ever more complex and called for new, more powerful brakes. These were initially cable-actuated, with hydraulic systems following shortly afterwards.
Fast forward to the present day, and disc brakes are everywhere. Road bike groupsets, such as Shimano 105 R7100 are now arriving in disc-only format and increasingly brands are coming out with disc-only framesets.
Technological advances are driving these changes, but many still pine for the days where rim brake was king. Whether it’s down to the simplicity of setting them up, the cheaper running costs or simply good old-fashioned tradition, many will argue that rim brakes are just as good as their disc counterparts and cannot be replaced.
But it’s not for us to make up your minds – here are the facts and everything you need to know about disc brakes versus rim brakes so you can decide for yourself.
Disc brakes vs rim brakes: At a glance
Disc brakes
- Better stopping power
- No rim heating issues
- Longer component lifespan
- Better wet weather performance
- More new disc-only groupsets
- More new disc-only framsets
Rim brakes
- Cheaper starting costs
- Easier maintenance
- More user friendly
- Normally lighter
- Less rigorous frame requirements
- Preference
The following content comes with a caveat. Disc brakes are available in different forms: cable actuated, hydraulic and hybrid. Cable-actuated disc brakes offer many of the benefits of their hydraulic counterparts however lack the same punchiness and self-adjustment qualities.
To truly show the differences between disc versus rim brake potentials, we'll be referring to hydraulic disc brakes throughout the rest of this article, as they are the most common type and represent the newest in disc brake innovations.
Disc brakes vs rim brakes: Which stops better?
Brakes have one principal purpose: slowing down the user. This is affected by weather conditions, user weight, braking duration and usage.
Heat is a huge factor when it comes to braking, as the hotter the brakes become, the less effective they are (a phenomenon known as ‘brake fade’).
This is a problem particularly on long descents where the rider will be using the brakes for extended periods. As such, heat dissipation has been at the forefront of brake innovation in recent years.
This is where disc brakes have excelled and gained popularity. By nature, disc brakes take braking force and heat away from the rim, redistributing it to a less problematic location i.e. the rotor.
With everything from pads with specific cooling fins, to disc rotors featuring large cut-outs to increase the surface area, disc brakes can incorporate more designs specifically aimed at heat reduction, aiding performance and reducing the risk of cooking the rotors.
Disc brakes also perform better in wet weather, though the sound of squealing disc rotors in the rain is enough to give anyone a fright.
Their performance gains are largely down to the different pad materials on offer, with metal (sintered) pads working better in rainy conditions.
Rim brakes usually use rubber-based compounds and thus struggle to gain purchase in less than ideal conditions.
In dry weather however, rim brakes can be very powerful, with more than enough power to lock up a wheel. The best quality calipers such as Shimano Dura-Ace hardly flex at all and offer excellent feel at the lever.
With a smaller surface area for braking and higher contact pressure produced by the calipers, disc rotors are less liable to external contamination from rain and water, and they clear filth more quickly.
And then there is emergency stopping. No one wants to be in this situation but in cycling, as in life, accidents happen.
In general, hydraulic disc brakes are more powerful than rim brakes which is useful not just for pros reacting in a peloton but for anyone riding outdoors.
All these factors are greatly influenced by rider usage. Properly bedding in your disc brakes is key to getting maximum efficiency out of them and poor usage can lead to a less than perfect riding experience.
Rim brakes, on the other hand, are straight forward and require next-to-no knowledge to operate.
Are disc brakes hard to maintain?
Disc brakes are notoriously fiddly to service, and no amount of YouTube tutorials can change that. Bleeding hydraulic disc brakes isn't hugely complicated, but it requires much more of the home mechanic than a simple rim brake cable adjustment.
Without a work-stand and a decent number of tools, home repairs on disc brakes can become an onerous or even insurmountable challenge. The clearance between pad and rotor is minute and just a small wobble in the disc can cause significant noise.
Even with Shimano’s claim that the new 105 brakes boast 10% more clearance than their predecessors, disc brakes can be a thorn in the side of those looking to repair their own bikes and they put some people off all together.
Rim brakes, on the other hand, are the home mechanic’s best friend. Worn out pads? No worries – undo the grub screw, pop ’em out, new ones in, done. Barrel adjusters make tension adjustments easy, and even replacing cables is fairly simple once you know how.
Another contentious point is cleaning. Rim brakes excel in this area as, bar covering your wheels in GT85, they tend to withstand whatever cleaning products are thrown at them.
In the other corner, disc brakes are more delicate flowers. Getting general degreasers, chain lube or even oil picked up off the road on your disc rotors is a recipe for disaster and can often lead to the pads, and sometimes even the rotors themselves, needing to be replaced once contaminated.
Disc brakes vs. rim brakes: Frame compatibility
As previously established, disc brakes provide more powerful braking, but with this comes extra strain on the bike itself. With more force going through the bike, particularly the fork, these areas must then be reinforced to handle it.
Because of the different requirements, bikes are normally designed from the ground up to accept either disc brakes or rim brakes, with just a handful of oddballs being compatible with both.
A benefit to the placing of disc brake calipers is that they allow for wider tyre clearances and this is one reason why discs are the default choice for gravel bikes.
Road rim brake calipers tend to limit how high and wide the tyres can sit, whereas disc brakes, mounted directly to the frame and fork, have no impact. Standard road rim brakes won’t usually accommodate tyres wider than 28mm, or 30mm at a push.
This also has benefits for the wheel design – wider rims that offer performance benefits can be used and, with no braking surface to consider and no braking heat to dissipate, they can be made lighter and, if desired, use a hookless design.
Though disc brakes originally entered mid-market, they quickly permeated the professional road scene. In 2021, the only team to be seen on rim brakes in the Tour de France was Ineos Grenadiers, but even they ditched them for the 2022 tour.
As such, fewer brands are producing their high-end bikes with a rim brake option, resulting in more of the cheaper models now featuring disc brakes as well.
In conjunction with this change, we are also seeing manufacturers, somewhat controversially, releasing disc-only groupsets, like recent updates in Shimano 105 R7100 and SRAM Rival AXS.
This is not to say that brands will stop making rim brakes altogether, but it is a nod to times where they may be much harder to source.
Are disc brakes more expensive?
A rim brake set up will consist of the brake caliper, brake pads and a wheel with a machined braking surface.
Disc brakes are similar, with a caliper, brake pads and then a disc rotor fitted to a disc brake-compatible wheel. As individual components, rim brake parts are cheaper to buy, service and repair. Given the more intricate design, disc brake components and framesets are typically more expensive.
However, component lifespan plays a factor in overall costs and sustainability. Rim brakes, as is in the name, make contact with the wheel’s braking surface. Over time, this braking surface wears down and will eventually need replacing. The wheel can either be rebuilt with a new rim or the wheel can be replaced entirely.
Disc brake pads make contact with the disc rotor which, when worn out, can simply be rather than replacing the whole rim. When combined with good quality hubs, disc brake wheels can typically outlive rim brake wheels for this reason and such, though not necessarily cheaper, can be less wasteful and give you more bang for your buck.
Which are better: Disc brakes or rim brakes?
So, does one clearly triumph over the other? Are rim brakes dead? Are disc brakes only necessary for WorldTour pros?
When it comes to out-and-out performance, the power of disc brakes cannot be denied, especially for wet weather, long descents and those emergency stops.
With brands dedicating ever more resources into disc brake development, we will continue to see the biggest developments in this area whilst rim brakes fall slightly to the wayside.
But, if you’re a budding home mechanic, mostly a fair-weather rider, or you like to keep your day-to-day repair costs to a minimum, the trusty rim brake will always have its place.
In a world of Specialized-type ‘innovate or die’ thinking, we see having the choice as a good thing. There are options for purists and pioneers alike.
Enjoy some geeky bike tech? Read our in-depth guide to the best rim width for road and gravel bikes.
