OK first up I confess - I'm a roadie. I am doing a ride in few weeks around Applecross which goes up the Bealach Na Ba in Scotland (see below). A friend did the main climb on the middle ring of his MTB but I've no idea about his gearing. What is a typical middle ring size and what range of rear cassettes do you use? I know this is all very vague. I think his bike is a hardtail and on the cheap side (less that £500). I'm just trying to guage the difficulty as I've never ridden up a constant 10km climb before. Here is the profile: