To favour the majority of our web traffic on mobile, the iframe implementation on this page - www.capewrathultra.com/results/ - has been wrapped in a div allowing it to behave with momentum based scrolling using -webkit-overflow-scrolling. Sadly this leaves desktop users with a double scroll bar, which I have given up trying to solve - whatever code I tweak within the iframe parameters it simply seems that I end back up with the status quo for best overall usability.
Current code:
<div style="-webkit-overflow-scrolling:touch; overflow-y: scroll; overflow: auto; height: 900px; width: