I've recently got an iPhone as my work phone so have been messing about with one of the GPS tracking apps (MotionX) on it. On the last two weekends, in pretty similar ground conditions, I rode the same 13 mile local loop, with a fair bit of climbing and some decent downhill sections, on two different bikes - this Sunday on my Epic and last Sunday on my Enduro. The Enduro (with coil shock and coil Pikes) is bound to be a good bit over 30lb and the Epic (with SID's, XTR, carbon and American Classics) is under 25lb - wouldn't surprise me if the Epic is 8lbs lighter.
Now I've read threads on here in the past that say bike weight doesn't make that much difference but in my case the Epic was over 12 minutes faster. That was despite more difficult weather conditions (hot and very humid) and a few minutes lost on the Epic getting myself sorted out after an off. Stops etc. would have been similar - perhaps slightly longer on the Epic as I chatted to another rider for a couple of minutes, and early on stopped to take a layer off. Possibly due to the weather I actually felt stronger when riding the Enduro.
I was expecting there to be some difference but nothing like that. So how much of that is likely to be down to weight and how much to other factors like geometry or gearing etc?



