The NAC 959XL is a 1-litre, two-compartment frame bag with strap loops on all four sides — which means it mounts in the main triangle, on the top tube, or along the downtube depending on your frame and how you ride. Four Velcro straps are included. Fitting takes about three minutes.
Pick your position
- Main triangle (against the top tube) — the classic spot: weight low and centred, best for bikepacking and long rides.
- Top tube — quickest access to the front pocket for phone, gels, and cards.
- Downtube — keeps the triangle clear on small frames or full-suspension bikes.
Installation steps
- Thread the four Velcro straps through the loops on the sides of the bag that will sit against the frame.
- Position the bag and check that no brake or shift cables run under any strap path — route straps around cables, never over them.
- Fasten the straps one at a time, starting with the two that carry the most load, pulling each snug so the bag sits flat against the frame.
- Check knee clearance — spin the cranks slowly and confirm your legs clear the bag through the full pedal stroke.
- Shake test — the bag should have zero swing or rotation. The frame-safe zips tuck into their flaps so nothing scratches your paint.
Packing tip
Heavy items (tools, tubes) go in the main compartment low and toward the frame; quick-grab items (phone, cards, a gel) live in the front pocket. Re-tension the straps after your first ride.
Going bigger for multi-day trips? See the 1.9L Xplore Triangle Bag, and our guide to building the ultimate bikepacking setup.