If I were going to ride on a gravel-covered road, I would use a rigid frame & fork from a mountain bike. They are plentiful and inexpensive, even for very good bikes with good components.

Those usually come with wide range gearing, cantilevered brakes, flat bars and decent seats. They usually have knobbies but those is easily swapped.

If you want fenders, you will find the frames can accommodate them but they will have to be added.

I'd prioritize finding a 29er because of the tire options you'll have. If not, stick with mountain bike wheels (26" rims/tires) for wide range compatibility/availability. The wheels may not be easily swapped if you have cantilevered brakes.


I did a conversion like this a while back and it was hugely successful.