Pop, roll, drop in. Physics all the way down.

When you push, your foot shoves the ground backwards and the ground shoves you forwards. Once you're coasting, rolling resistance (C_rr × m g) slows you at a = C_rr × g, so you roll a distance d = v² ÷ (2 C_rr g) before stopping (ignoring air drag).

Pushing well

• Weight on the front foot, over the front truck, so the board stays under you while the back foot pushes.
• Short, smooth pushes beat big lunges: you stay balanced and can stop.
• Learn to stop first: foot-brake (drag the back foot), or step off safely at low speed.

You stay up as long as your centre of mass is above the area between the wheels. Drift outside it and gravity creates a turning moment that tips you off. Bent knees lower your centre of mass and give you room to correct. Whether you ride left foot forward (regular) or right foot forward (goofy) is simply what feels natural.

How trucks steer

Skateboard trucks are built so that tilting the deck swings the axles: lean toe-side or heel-side and the board carves that way. To hold a curve of radius r at speed v you must lean into it at tan φ = v² ÷ (g r).

Snapping the tail down pivots the board over the back wheels; the ground pushes back on the tail and the board pops up. You jump at the same moment and slide your front foot forward, which drags the nose up and levels the board under you. Once you're in the air you're a projectile: to clear a height H you need an upward speed of v = √(2 g H), and you'll be airborne for about t = 2v ÷ g.

Why practice matters more than strength

Height needs √h more speed, so twice the height needs only about 1.4 times the pop. Timing (snapping the tail exactly as you jump) matters more than force. Practise standing still on grass or carpet first, then rolling slowly.

Dropping in from height h, you reach the bottom at v = √(2 g h) (ignoring friction). Following a curve of radius r needs a centripetal force m v² ÷ r, so at the bottom of the transition the ramp pushes on you with m g (1 + 2h ÷ r): more than your weight.

Pumping

Crouch as you go into the curve, then stand up through it while the ramp is pushing hardest. You do work against that extra force and gain energy, like pumping a swing. That's how bowl skaters keep going without pushing.

Average force during a stop depends on how far you take to stop: average deceleration = v² ÷ (2 × stopping distance). Falling from standing, your body (centre of mass about 1 m up) reaches the ground at about √(2 × 9.81 × 1) ≈ 4.4 m/s.

How to fall

• Get low when you feel it going: less height, less speed.
• Roll onto your shoulder or side instead of reaching out with a straight arm.
• On a ramp, slide down on your knee pads.
• Helmet always. World Skate's competition rules (used in the RSFI rulebook) require all park skaters, and street skaters under 18, to wear a helmet in practice and competition.

A wheel turns once per circumference: revs per second = v ÷ (π d). Smaller wheels spin faster for the same speed, and the bearings take it.

Hard or soft wheels?

Bigger, softer wheels deform over stones and cracks and meet them at a gentler angle, so they suit rough streets and cruising. Smaller, harder wheels are lighter and slide more predictably on smooth park surfaces.

How contests are scored

The RSFI skateboarding rulebook follows World Skate rules for the two Olympic disciplines, street and park, with no age limits. In park, skaters get at least two runs of 30–50 seconds; five judges score each run from 0 to 100, the highest and lowest scores are dropped and the remaining three averaged. The best run counts. In the Olympic street format, skaters do 2 runs of 45 seconds and 5 single tricks; the best run plus the 2 best tricks make the score.