Castiron Grip ONE — Youth Velcro Climbing Shoe

The wall doesn't care how old you are. The ONE doesn't either.

Young climbers who are serious about the sport need a shoe that takes them seriously. The ONE is built for kids who've outgrown beginner footwear and are ready for real performance — a secure velcro closure, flexible sole, and high-friction rubber that reads the hold before they do.

Not a starter shoe. Not a toy. A proper climbing shoe built to the Castiron standard — just sized for the next generation.

Formerly Rock Planet ONE — same production, same performance. Castiron standard.

Built For

• Youth and junior climbers progressing beyond beginner level
• Indoor bouldering — gym walls, youth circuits, competition prep
• Sport climbing — first routes, building technique and footwork
• Climbing clubs and youth programmes
• Kids who are serious about the sport, not just trying it

Technical Specs

• Closure: Velcro — fast, secure, adjustable between problems
• Sole: High-friction rubber — precision grip on gym holds, slab, and vertical
• Toe box: Slightly tapered — more precision than a beginner shoe, no aggressive downturn
• Upper: Synthetic microfiber — durable, breathable, easy to clean
• Heel: Structured heel cup — secure lockdown for dynamic movement
• Sizes: EU28–35 (US 10C–4Y)
• Colours: Yellow, Black, Orange
• Weight: Lightweight — built for young climbers moving fast on the wall

Why Velcro for Youth Climbers?

Velcro gives young climbers the best of both worlds — the precision of a performance shoe with the convenience of fast on/off between problems. No laces to tie mid-session. No slip-on looseness. Just a secure, adjustable fit that stays locked in whether they're on a slab, a vertical face, or their first overhang.

The ONE's slightly tapered toe box introduces young climbers to performance fit without the discomfort of an aggressive downturn. It's the bridge between the Little ALIEN and the adult PR23 — the shoe that builds the footwork habits that last a career.

The Castiron Grip Standard

Every Castiron Grip shoe is built to the same performance standard — from the ONE to the advanced PR23 and N23. The rubber compound, the construction quality, the attention to fit — none of that changes based on age or price point. Young climbers deserve the same standard as adults on the wall.

The ONE is where serious youth climbing begins. The PR23 and N23 are where it goes next.

Sizing Guide

The ONE runs true to EU size. Order your child's normal EU shoe size for a comfortable fit. For a snugger performance fit, size down 0.5 EU. EU28–35 covers youth climbers from approximately age 6 through to junior competition level.

US size equivalents: EU28 = US 10C · EU29 = US 11.5C · EU30 = US 12C · EU31 = US 13C · EU32 = US 1Y · EU33 = US 2Y · EU34 = US 3Y · EU35 = US 4Y

Formerly Rock Planet

The ONE was previously sold as Rock Planet ONE — used in youth climbing programmes and clubs across Europe, the UK, Australia, and North America. In 2026, the Rock Planet climbing line became Castiron Grip. Same shoe. Same production standards. Castiron identity.

FAQ

Is this the same as the Rock Planet ONE?
Yes. Same production, same performance standards, same shoe. Rebranded under Castiron Grip in 2026.

What age is the ONE for?
EU28–35 typically fits children aged 6–12 depending on foot size. It's designed for youth climbers who are progressing beyond their first climbing shoe and want more performance.

What's the difference between the ONE and the Little ALIEN?
The Little ALIEN is a slip-on beginner shoe — flat profile, easy on/off, ideal for first-timers. The ONE has a velcro closure and a slightly tapered toe box, giving more precision and performance for youth climbers who are developing their technique.

When should my child move to the ONE from the Little ALIEN?
When they're climbing consistently and want more precision from their shoe — typically after 3–6 months of regular climbing. The velcro closure and tapered toe box of the ONE will immediately improve their footwork on technical holds.