The heavy-handed ­response of the constabulary ­towards a collection of cyclists ­intending to pedal around Centennial Park with their hair in the wind last Sunday as a peaceful protest calling for reform to mandatory helmet laws marked another low point in the fraught relationship in Sydney between cyclists, drivers and the long arm of the law. Similar rides in other cities across Australia and New Zealand passed without incident. But in Sydney, police dispatched seven police cars to intercept and stop the planned “helmet optional” ride around the park’s Grand Drive cycle lane, threatening participants with $330 fines (among the highest anywhere in the world).