Rezo Brake Discs for 125cc Motorcycles

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Tags: wavy brake discs , motorcycle brake discs

Rezo brake discs for 125cc motorcycles

It goes without saying that brake discs are an essential and important component of every hydraulic braking system. They must be perfectly flat, thick enough to cope with the forces and energy applied, and made of a good quality steel that will not distort. As long as they fulfil those requirements you can argue that that they are not as crucial to the efficiency of the system as the pads, the caliper, the master cylinder, the hoses and the brake fluid. But it is not all about function with brake discs, their form is also important.

Form and Function

I remember when little attention was paid to the aesthetics of a brake disc, when function was more important than form. The days of solid discs, some made of cast iron that would rust at the first hint of moisture. They did not look great. Then someone from the world of road racing came up with the idea of drilling holes in the disc, and someone in the off-road world came up with the idea of cutting shapes out of the perimeter so the contour was no longer round, but wavy. There were good reasons for both these developments. Drilled holes help to disperse water, dirt, and brake dust, and improve cooling. A wavy contour scrapes mud and water off the pads to keep the friction surface clean. Both features make the disc lighter, reducing rotational inertia and unsprung weight. When these ideas caught on the incidental improved look of the discs became the realm of designers who ever since have been coming up with new patterns. Discs are now an important aesthetic component of the motorcycle, and riders spend hours deciding which wave pattern they prefer and whether to have round or oblong holes.

Motorcycle owners love to personalise and customise their motorcycles, and aftermarket brands such as Rezo offer stylish discs at a much lower price than OEM ones, the cost of which can be prohibitive. There is growing demand for aftermarket products at the 125cc level, including the all-important Scooter market. These markets are important to Rezo, who have recently introduced a new line of discs for the Yamaha YZF-R 125 and MT-125, Honda CBR 125, Varadero, MSX Grom and Monkey, KTM Duke and RC, and for Scooters such as the Yamaha N-Max, and the Honda PCX, Vision and SH Mode. Rezo brake discs are manufactured using high grade (410) stainless steel. The discs are cut using a CNC controlled laser and finished with dual diamond grinders to ensure true flatness and high braking performance.

The looks and finish of the new discs are important so don’t spoil them by using the tarnished bolts from the old discs, finish the job properly with a set of new bolts. Quality is paramount when it comes to disc bolts, and Pro-Bolt are the brand that many owners go for – the reputation they have for strong bolts with a quality finish that stands the tests of time has been gained because of the product, not clever marketing. Why not treat yourself to a set.

Fitting new discs

Brake discs are easy to fit but you do need to remove the wheel. Not a difficult task, but bikes without a centrestand need supporting, and paddock stands are the best way to do this. You need a torque wrench, some threadlock and some brake cleaner, and a new set of brake pads – do not use old brake pads on new discs. Refer to a manual for the torque setting for the disc bolts. Once the wheel is out it is simply a matter of unscrewing the bolts and removing the disc, along with the ABS pulse ring where fitted and if secured by the disc bolts. Before you fit the new disc make sure the seating surface on the hub is spotless so the disc sits perfectly flat. Apply threadlock to the bolts, do not forget to refit the pulse ring where necessary, and tighten the bolts evenly in a criss-cross sequence to the correct torque setting. Clean the new disc with brake cleaner, fit the new brake pads and you are good to go, after refitting the wheel of course!

Note: MPW are pleased to announce that we will soon have the full range of Haynes and Clymer Service and repair Manuals available to buy on our website.