Thank you for the web site and to answer your question Sara, I have a triple but I'm not quite sure by what you mean by chain rub? If going to the large ring can increase speed on the flat then I can see the advantage, but you are pedaling harder- wear and tear on the joints, not to mention it must be exhausting to keep up for long periods of time. So for most of us non racers best used for short bursts only- like when the men are dropping you on a club ride?