Speedycom Thumb Brake. Race proven by McAdoo racing at the Ulster Grand Prix whilst breaking the lap record at 133.284mph What it does: Fits on the left (upto 54mm diameter) and allows you to use the rear brake with your left thumb. This kit was specifically designed for racing and track days. Benefits: Easier control of the rear brake enabling you to control wheelies whilst cresting a rise in the track, or for those lightning quick race starts without fear of flipping the bike. More importantly it is excellent for positioning the bike mid-corner as you can control rear suspension compression, by dragging the rear brake, which causes the motorcycle to tighten its line allowing the power to be applied earlier, enabling a faster corner exit speed. The latest evolution provides the user with the ability to alter the lever position to obtain that custom feel. Full Race kit includes: Black anodised aluminium fork clamp – 54mm fork diameter (smaller fork diameters require shimming, which can be provided at no extra cost) Black anodised aluminium thumb brake lever (adjustable for ratio) Stainless steel fixings with anti-vibration washers Brembo 13mm bore master cylinder We can also supply Brake line, resivoirs and pipe for your Thumb Brake.