So, you've got more power, faster acceleration and higher top speed. But it's no good arriving sooner unless you can also stop quicker – as any racer will attest. Are your brakes keeping up with your motorcycle's ever-faster performance? If not, it's high time to consider how you can help them catch up.
When it comes to upgrading your brakes, there are all kinds of different options available. You can spend anything between 1500 THB and 80,000 THB on improving your motorcycle's stopping power, so you need to have a long think about what you can afford and what you really need. Of course, the best aftermarket solution for you also depends on what kind of riding you do: Are you a trackday addict who wants to out-brake your friends into the corners, or do you just want more confidence in avoiding dopey motorists on your daily commute? Whether you want more power, improved feel, or sharper initial bite – you can tweak your brakes to suit your needs.
Many modern motorcycles come with excellent brakes as standard, and if they're poor, then maintenance may be the first issue. Make sure the basics are covered before taking the upgrade route – fresh pads, fluid and bleeding can transform a tired stock brake setup. If you still need more, then the first and most obvious improvement is a set of braided brake lines. Even though most sportsbikes nowadays have decent-quality radial calipers, many are still fitted with conventional rubber hoses. The problem with rubber brake lines is that they expand with use and gradually wear out. This means that when you squeeze the brake lever some brake pressure is used filling the hoses beyond their intended capacity – rather than pushing your brake pistons. As a result, your brake pads are not pushed as far as they should be; and some of the force you're applying at the lever is wasted 'inflating' the hoses – all of which means reduced braking power and less feel. A set of stainless steel braided lines will eliminate this effect by ensuring all of the force you apply at the lever finds its way to your calipers. Unless you have the equipment and ability to confidently bleed your brakes, it's sensible to get replacement hoses professionally fitted.
Braking relies on friction between two surfaces – your discs and your brake pads. Have a feel of one of your motorcycle's smooth, shiny disc: It is obviously not a rough, grippy surface. In order to generate friction, your disc relies on a special relationship – physical and heated – with your brake pads. This is why your discs are only as good as their compatibility with your pads and vice-versa. A standard disc is made from stainless steel, which provides good longevity and corrosion-resistance. But stainless-steel contains slippery elements such as chromium, so is not ideal for creating friction. In order to produce acceptable braking performance from a stainless-steel disc, you need to use sintered brake pads, which contain shards of metal. This metal-to-metal contact gives a high degree of initial bite – by immediately creating high levels of friction and heat. Thus, under hard use, a sintered brake pad may generate too much heat, resulting in less effective braking and possibly warped discs.
High-performance discs are made from iron rather than stainless-steel, Iron is more conductive to friction than stainless-steel; it generates and dissipates heat more effectively. Although less hard-wearing and more prone to rust than stainless-steel and regular steel, iron discs can be used with ceramic or organic brake pads. Unlike sintered pads these types do not contain metallic fragments, and therefore do not generate heat as rapidly, and may produce less initial bite. Once up to temperature, however, an organic brake pad is more effective – it is less prone to cause overheating, so braking performance will not fade with hard use. In fact, some organic brake pads perform better as they heat up – these have what is known as a 'progressive torque curve', while others offer a stable level of braking regardless of temperature, called a 'flat torque curve'.
In theory, the best disc is the one with the greatest surface area, on which friction can take effect – but in reality the situation is more complicated. The problem is, dirt and water get in between the brake pads and disc – as well as dust created by the pads – and all these contaminants need to be cleared. This is why discs have been drilled with holes since the '60s. More recently, we've seen a bloom in the use of wavy discs. Why? The first wavy disc, created by Galfer, was designed to clear dirt and grime – more effectively than a drilled disc. In truth, the practical benefits of wavy discs are relatively limited; there burgeoning popularity has a great deal to do with their aesthetic appeal. The profile of a disc is far less important than the material it is made from and the quality of manufacture – it must be uniformly flat.