Hamilton's speed on bikes caused concern, van der Mark reveals

https://www.motorsport.com/wsbk/news/hamilton-superbike-test-van-der-mark/4310730/https://www.motorsport.com/wsbk/news/hamilton-superbike-test-van-der-mark/4310730/ https://cdn-6.motorsport.com/images/amp/6zQBpPaY/s6/world-superbike-hamiltion-jere-2.jpg