On One Big Dog- 4130 Steel Hardtail Boost Mountain Bike frame- 29er Size Large. Bought new to transfer parts to my titanium frame, hence this frame will be surplus to requirements. Couple of very minor paint chips, see pics. Brake Type: Disc, post mount only. Axle size: Boost spacing 148mm rear. Recommended fork travel: 120-130mm. Max tyre clearance: 2.35 (29).