If you're looking for the fun stuff within a shorter drive of Boulder, I'd recommend:
White Ranch (Golden)
Hall Ranch (Lyons)
Left Hand OHV (North Boulder)
Horsetooth/Lory SP (Ft. Collins)
Bobcat Ridge (Loveland)
Golden Gate Canyon SP (Golden)
If you want specific routes for any of these, shoot me a PM and I'm happy to send you more info. As long as you're OK climbing with a bigger/heavier bike, I'd recommend more travel than less... sure, you can ride any of these trails with a 130mm trail bike, but it's a lot more fun with 150/160 underneath you.
White Ranch (Golden)
Hall Ranch (Lyons)
Left Hand OHV (North Boulder)
Horsetooth/Lory SP (Ft. Collins)
Bobcat Ridge (Loveland)
Golden Gate Canyon SP (Golden)
If you want specific routes for any of these, shoot me a PM and I'm happy to send you more info. As long as you're OK climbing with a bigger/heavier bike, I'd recommend more travel than less... sure, you can ride any of these trails with a 130mm trail bike, but it's a lot more fun with 150/160 underneath you.