Originally Posted by
kamtsa
You are going over some rough surfaces. What kind of tires are you using?
I am avoiding going over surfaces better than that but maybe my Marathons can handle more than I expect.
My wife and I have ridden up Mount Tamalpais (Marin County, CA, USA) on a fire road with rough and loose gravel and sand. She on her Moulton with Schwalbe Stelvios and my on my Birdy with the original Maxxis (now Stelvios too).
I think Jur is right - the main problem might be grip. We were both fine going up. My fatter Maxxis tires were more confidence inspiring on the way down - but we were both a lot slower than the MTB folks who were bombing down the path!
If you do lots of offroading, it might be worth getting knobbly tires. But for the occasional jaunt offroad your Marathons will be fine, just take care on any loose surfaces.