UMA Racing High Friction Weighted Rollers come in a selection of weightages, made to precise manufacturing standards as always. Measuring 15x12MM,the lighter roller sets will give you quicker acceleration and a longer time in lower gear ratio but it will require higher RPMs to reach a higher ratio. You may not be able to reach the highest ratio if your engine speed is not quick enough. Heavier weights would be like the opposite, good for torquey set ups. You can pick up a few sets to mess around to suit your riding style. Size and weight marked at its sides for easy recognition.
This roller size is suitable for the Yamaha Nouvo scooter models with air cooled engines, please check first!