Super-light, "skinny" semi-aero box section alloy rims will ensure the fastest ride for Junior and Mini riders. Stainless nipple eyelets allow high tension spokes for a stiff wheel that transfers chain drive into forward motion with minimum effort. Front or Rear (machined cnc sidewall brake surface) specific versions.Features:20 x 1 1/8" (tyre bead diameter 451mm)Ultra slim 19mm wide.Box Section with sleeved joint.Niobium Alloy material with T-10 heat treatment.28H Black anodised. 32H Black with Silver CNC braking surface.Note:Â 45Kg (100lb) rider weight limitRecommended Spoke Tension: Front: 80 to 100Kgs. Rear: 100 to 135Kgs.