How to choose the right size
Specialized uses two sizing systems — S-Sizing for trail and enduro bikes, and traditional sizes for road, gravel and XC bikes. We will help you find the right one.
S-Sizing sizes
Size by riding style
Why should your inseam decide your bike size? S-Sizing is a Specialized sizing system that lets you choose a bike based on how and where you ride — not just your height.
A smaller S-Size number (S1, S2) = a more agile bike with a shorter reach and quicker changes of direction. A larger number (S5, S6) = a more stable bike with a longer wheelbase and calmer handling at high speed.
S-Sizing is used by: Stumpjumper, Enduro, Status, Turbo Levo, Turbo Kenevo and other trail/enduro bikes.
Which S-Size matches your height?
| Rider height | S1 | S2 | S3 | S4 | S5 | S6 |
|---|---|---|---|---|---|---|
| 152–160 cm | ||||||
| 158–168 cm | ||||||
| 165–175 cm | ||||||
| 173–183 cm | ||||||
| 180–190 cm | ||||||
| 188–196+ cm |
The height ranges overlap on purpose — in the overlap, your riding style decides which size to choose.
S-Sizing vs traditional sizes
SM, MD, LG — classic “T-shirt” sizes — set the frame size by your height and inseam. This works great for road and XC bikes, where pedalling efficiency is key.
But for trail and enduro riders, riding style matters more — and that is exactly what S-Sizing addresses. Instead of one “correct” size, you can choose from several that differ in agility and stability.
Both systems are right. It depends on the category of bike you are buying.
Road bike sizes
Numeric sizes by height
Specialized road, gravel and cross-country bikes use numeric frame sizes (44, 49, 52, 54, 56, 58, 61, 64), which roughly match the seat tube length in centimetres.
The right size depends primarily on your height and body proportions — a rider with longer legs and a shorter torso may prefer a larger frame, while a rider with a longer torso may prefer a smaller one.
This system is used by: Tarmac SL8, Aethos, Roubaix, Allez, Crux, Diverge, Epic, Chisel, Rockhopper and more.
Which size matches your height?
| Rider height | Frame size |
|---|---|
| 142–152 cm | 44 |
| 152–163 cm | 48 |
| 158–168 cm | 50 |
| 163–170 cm | 52 |
| 170–178 cm | 54 |
| 175–183 cm | 56 |
| 180–188 cm | 58 |
| 188–196 cm | 61 |
| 196–205 cm | 64 |
The ranges overlap on purpose — if you are between sizes, consider your body proportions (longer legs = larger frame, longer torso = smaller frame) or ask a bike-fitting expert.
Which road bike should you choose?
Specialized offers road bikes for every riding style — from race bikes to comfortable endurance models. Each model has its own geometry, but the size chart is the same.
Tarmac SL8
Race · Aero · Light
The fastest road bike. Aggressive geometry for maximum performance. Aero frame, minimal weight. Sizes 44–61.
Aethos
Light · Comfortable · Climbing
An ultralight bike for climbers and purists. Classic road geometry focused on comfort and low weight. Sizes 49–61.
Roubaix SL8
Endurance · Comfort · Long miles
A road bike for long distances. More upright position, Future Shock suspension that absorbs vibration. Sizes 49–61.
Kids’ bikes
A kids’ bike size is chosen by the child’s height and age. Specialized has developed a four-step system that grows with your little rider.
A young rider’s journey
From a balance bike to a first bike with pedals and on to a full-size kids’ mountain bike. Each step is designed for a specific stage of a child’s development.
1. Balance bike
Hotwalk · up to 3 years · 75–90 cm
The perfect start. Children learn balance, steering and coordination without pedals. A light frame and low seatpost give them confidence.
2. First pedals
Jett 16 / Riprock Coaster · 3–7 years · 95–120 cm
Moving on to pedals. Light, easy-to-handle bikes designed so that small hands and feet can manage everything comfortably.
3. A proper bike
Jett 20–24 / Riprock 20–24 · 6–12 years · 110–150 cm
Gears, disc brakes, suspension — a real bike on a smaller scale. Ready for trails, school and adventures.
Which bike for which height?
| Child’s height | Age | Recommended model |
|---|---|---|
| 75–90 cm | up to 3 years | Hotwalk (balance bike) |
| 90–105 cm | 3–5 years | Riprock Coaster 12 / 16 |
| 95–115 cm | 4–6 years | Jett 16 |
| 105–120 cm | 5–7 years | Riprock Coaster 20 |
| 110–130 cm | 6–9 years | Jett 20 |
| 120–145 cm | 7–11 years | Jett 24 / Riprock 24 |
| 130–150 cm | 9–12 years | Riprock 24 |
Age is only a guide — the child’s height always decides. If your child is between sizes, we recommend the larger bike so they do not outgrow it too quickly.
Still not sure?
Get in touch and we will be happy to help you choose the right size.
