Estimated reading time: 12 minutes
Quick Answer: The Castiron Grip PR23, N23, and SWIFT are all built with fully synthetic uppers — no leather, no animal-derived materials. All three are vegan climbing shoes suitable for gym, sport, and multi-pitch climbing across the UK.
Contents
- What makes a climbing shoe vegan
- Synthetic vs leather in climbing shoes
- Castiron Grip vegan models
- Model comparison table
- PR23 — performance vegan option
- SWIFT — all-round vegan option
- N23 — entry-level vegan option
- How synthetic performs vs leather
- Caring for synthetic climbing shoes
- FAQ
- UK climbing resources
What Makes a Climbing Shoe Vegan
A vegan climbing shoe uses no animal-derived materials anywhere in its construction. In conventional climbing shoes, the most common animal-derived material is leather — used for the upper, lining, or both. Leather provides stretch characteristics that synthetic materials historically struggled to match, which is why it dominated climbing shoe construction for decades.
Modern synthetic microfibers have largely closed that gap. Today's high-quality synthetic uppers offer comparable fit precision, acceptable stretch behaviour, and in some respects better performance than leather — particularly for climbers who want a consistent fit from session one without a prolonged break-in period.
A fully vegan climbing shoe uses synthetic microfiber or similar man-made materials for the upper, a synthetic lining (or no lining), and rubber compounds and adhesives that contain no animal products. The Castiron Grip adult line — PR23, N23, and SWIFT — meets this standard.

Synthetic vs Leather in Climbing Shoes

| Property | Synthetic | Leather |
|---|---|---|
| Break-in period | Minimal — fits well from session one | Longer — stretches and moulds over time |
| Stretch | Low — size stays consistent | Higher — can stretch up to a half size |
| Breathability | Varies by construction | Generally higher |
| Odour resistance | Better — less bacterial absorption | Can retain odour over time |
| Sizing consistency | High — predictable fit | Lower — account for stretch when sizing |
| Vegan | Yes | No |
Castiron Grip Vegan Models

| Model | Closure | Profile | Best for |
|---|---|---|---|
| PR23 | Single velcro | Aggressive | Advanced sport, steep routes, overhangs |
| SWIFT | Lace-up | Moderate | All-round, slab, multi-pitch, gym |
| N23 | Dual velcro | Moderate downturn | Gym, sport climbing, beginner to intermediate |
PR23 — Performance Vegan Climbing Shoe

The PR23 is Castiron Grip's performance-tier shoe — aggressive downturn, single velcro closure, low volume, and a fully synthetic upper. For UK climbers who want maximum performance on steep sport routes, overhangs, and technical face climbing without using animal-derived materials, the PR23 is the top-of-range vegan option. Strong choice for hard limestone at Malham, gritstone at Stanage, and sport routes in North Wales.
- Closure: Single velcro
- Profile: Aggressive downturn
- Volume: Low
- Upper: Fully synthetic — no animal-derived materials
- Best grades: French 7a–8c+ / British E4+
- Best for: Steep sport, overhangs, Malham, Pembroke hard routes, North Wales limestone
SWIFT — All-Round Vegan Climbing Shoe

The SWIFT is the all-round option in the Castiron Grip adult line — lace-up closure, moderate downturn profile, medium-high volume, and a fully synthetic upper. It suits the widest range of terrain types and foot shapes, making it the most adaptable vegan climbing shoe in the range. For UK climbers moving between wall sessions, gritstone edges, limestone sport, and multi-pitch trad, the SWIFT covers all bases.
- Closure: Lace-up — precise fit adjustment
- Profile: Moderate
- Volume: Medium-high
- Upper: Fully synthetic — no animal-derived materials
- Best grades: French 5–7b / British HS–E3
- Best for: All-round use, slab, trad multi-pitch, gym, Stanage, Lake District, Pembroke
N23 — Entry-Level Vegan Climbing Shoe

The N23 is the most accessible adult shoe in the Castiron Grip line with dual-velcro closure, a moderate downturn profile, and a fully synthetic upper. For UK climbers starting out on synthetic or vegan footwear, the N23 delivers solid gym and beginner crag performance without any animal-derived materials.
- Closure: Dual velcro
- Profile: Moderate downturn
- Volume: Medium
- Upper: Fully synthetic — no animal-derived materials
- Best grades: French 4–6b / British Severe–HVS
- Best for: Gym, indoor bouldering, intro routes at Stanage, Pembroke, Peak District limestone
How Synthetic Performs vs Leather
For most gym and sport climbing applications, a quality synthetic upper performs on par with leather. The primary difference climbers notice is the break-in curve. Leather shoes stretch and mould to the foot over multiple sessions; synthetic shoes deliver their true fit immediately. For UK climbers dealing with damp conditions at outdoor crags, synthetic materials also tend to handle moisture slightly better than unlined leather.
Sizing is more predictable with synthetic shoes. Leather shoes are often sized down aggressively to account for stretch; synthetic shoes require less aggressive sizing down because the material holds its shape. For beginner and intermediate climbers at UK walls and intro crags, this predictability is an advantage.
Caring for Synthetic Climbing Shoes
- Air dry after every session — particularly important in the UK's damp climate
- Use a shoe brush to remove chalk and dirt from the rubber sole
- Store in a breathable bag, not a sealed container
- Avoid machine washing — hand wash with mild soap and air dry fully
- Resole when rubber wears through — do not wait until the rand is damaged
FAQ
Are all Castiron Grip climbing shoes vegan?
The adult models — PR23, N23, and SWIFT — use fully synthetic uppers with no animal-derived materials. Check individual product pages for the kids range for current material specifications.
Do synthetic climbing shoes perform as well as leather on UK rock?
Yes, across the range of UK climbing terrain. The SWIFT's moderate profile suits gritstone and limestone equally well. The PR23 handles steep sport and overhangs. The N23 covers gym and beginner crag use.
Should I size differently for synthetic climbing shoes?
Synthetic shoes stretch less than leather, so you may not need to size down as aggressively. Start at your normal sizing down recommendation and adjust rather than over-sizing down.
Can I resole vegan synthetic climbing shoes?
Yes. Resoling extends shoe life significantly and is available for synthetic shoes just as for leather.
Are the Castiron Grip kids shoes also vegan?
Verify current material specs on the individual product pages for HUG, ONE, and Little ALIEN before making a purchase decision based on vegan criteria.
UK Climbing Resources
Continue the UK climbing shoe hub:
Flat feet climbing shoes | Best climbing shoes under £100 | Indoor climbing shoes | Kids climbing shoes
Written by T-K