It’s all about relative targets though Sandwicheater
I joined Tons 500 mile a month group because last year I was averaging 400 – 450 a month and it was a nice ‘target’ to push for, so far for 2014 I’ve done a 400, 200 and 580 mile months, with the split being about 30 – 40% offroad and 60% road miles.
I tend to view it in terms of ‘rides’ and the actual miles being a byproduct if that makes sense?
ie: I’m going out for an MTB/Road ride, and when I get back the miles have increased, I rarely go out with a specific mileage target in mind for the ride, it’s normalyl a case of pick a route that I know takes the right amount of time I have free and either cut short or extend depending on mood or conditions.
I don’t beat myself up if I don’t hit the 500, but its a fantastic motivator to get you out the door on the days went you might otherwise think twice or bail out.
If you want to increase your time on the bike then you could look for little ways to extend you normal rides rather than trying to cram in more of them. Ride to the forest if you normally drive, or even just park somewhere other than the main car park, liek the edge of the forest where one of the trails goes past or something (if you can) so you have to ride in to meet your mates, and then ride back out to finish, gives you a little more trail time for almost free 🙂