How to Fit a Race Suit: Sizing, Layering & Airbag Compatibility

• Snug, not tight: The suit should feel close to your body in riding position, with no excess fabric bunching
• Try it on in riding position: Crouch into a tuck position - arms extended, knees bent - to check for restriction
• Account for armor and airbag: Always fit with the same protection you'll wear on track
• Break-in is real: Leather stretches 3-5% over the first few sessions
• Safety first: Armor must stay in position during movement - if it shifts significantly, the fit is wrong

Race suit fit isn't about comfort alone - it's a critical safety factor validated by decades of crash data and FIM homologation standards. Here's why proper fit is non-negotiable:

• Armor stays positioned: CE-certified protectors remain over shoulders, elbows, hips, and knees during impact
• Abrasion resistance: Leather stays in contact with your body, preventing fabric from rolling up during slides
• Airbag deployment: Tech-Air® systems require specific fit tolerances to deploy correctly and protect vital areas
• Mobility & performance: Proper articulation allows full range of motion without restriction
• Reduced fatigue: Ergonomic fit reduces muscle strain during long sessions.

• Armor migration: Protectors shift away from impact zones
• Circulation issues: Overly tight suits restrict blood flow, causing numbness and fatigue
• Compromised airbag: Incorrect fit prevents proper airbag inflation or coverage
• Restricted movement: Limits lean angle, throttle control, and body positioning
• Premature wear: Stress points tear faster when fabric is overstretched

Professional riders work with Alpinestars technicians to achieve millimeter-perfect fit because even small deviations affect crash protection. While you may not have access to a factory fitting, following this guide will help you achieve race-ready fit at home or with your local dealer.

Alpinestars race suits use a sophisticated sizing system that accounts for height, build, and riding position. Unlike street clothing, race suit sizing prioritizes ergonomic fit in the crouch position - not standing upright.

Most Alpinestars race suits are available in three fit variations to accommodate different body proportions:

Fit Type Best For Key Characteristics:

Two riders of the same height can require different fits based on leg length. A 5'10" rider with a 32" inseam may need a standard fit, while a 5'10" rider with a 28" inseam may need a short fit. Always measure your inseam and compare it to the sizing chart rather than relying on height alone.

Accurate measurements are the foundation of proper fit. You'll need a flexible measuring tape and a friend to help with hard-to-reach areas. Wear only thin base layers or underwear - no bulky clothing.

Measurement How to Measure Critical Notes:

Once you have your measurements, compare them to the Alpinestars sizing chart for your specific suit model. Sizing can vary slightly between models - always check the product-specific chart rather than assuming your size is consistent across all suits.

General Alpinestars Men's Race Suit Sizing (Standard Fit):

Size Chest (inches/cm) Waist (inches/cm) Hips (inches/cm) Height (inches/cm)

If your measurements fall between two sizes, consider these factors:

• Go smaller if: You're closer to the lower end of both size ranges, prefer a race-tight fit, or plan to wear minimal layers
• Go larger if: You're closer to the upper end of ranges, have a muscular build, plan to use a Tech-Air® airbag system, or prefer slightly more comfort
• Remember: Leather stretches 3-5% during break-in, so a slightly snug new suit will conform to your body

Once you have a suit in hand, methodically check each area. Always try the suit on with the same base layers, chest protector, and back protector you'll wear on track - and if you plan to use a Tech-Air® system, wear it during the fitting.

• Shoulders: Armor should sit centered over the shoulder joint, not sliding forward or back
• Chest: Suit should be close to body without restricting breathing; chest protector shouldn't shift
• Waist: Snug but not constricting; you should be able to take a full breath
• Hips: Hip armor centered over hip bones
• Thighs: Close fit without restricting leg movement
• Knees: Knee armor should sit centered over kneecap when standing - it will shift up when you crouch
• Ankles: Suit should extend to cover ankle bones; no gap between suit and boots
• Arms: Sleeves should reach wrist bones; elbow armor centered over elbow joint

Crouch into a full tuck position: knees bent, arms extended as if gripping handlebars, back curved forward.

• Back: No excessive pulling or bunching; back protector stays centered on spine
• Shoulders: Armor remains in position; no restriction reaching forward
• Elbows: Armor stays over elbow joint with arms extended
• Knees: Armor shifts up to cover kneecap; should feel snug but not painfully tight
• Lower back: No large gap exposing skin between suit and back protector
• Crotch: Should feel snug but not cutting in; excessive tightness causes discomfort and circulation issues
• Ankle/wrist cuffs: Should stay in place, not ride up exposing skin

• Arm circles: Full range of motion without binding
• Deep knee bends: Squat fully without excessive resistance
• Torso twists: Rotate shoulders left and right to check for restriction
• Neck movement: Turn head fully left and right; collar shouldn't dig in
• Walk around: Spend 10-15 minutes moving in the suit; areas that feel tight may indicate poor fit

• Armor shifts more than 1 inch (2.5cm) when you move into riding position
• Numbness or tingling in hands, feet, or legs after 5 minutes
• Visible gaps between suit and body in critical areas (lower back, wrists, ankles)
• Inability to fully extend arms or bend knees without painful restriction
• Excess fabric bunching in armpits, crotch, or behind knees
• Knee armor sits below kneecap when crouched

If you experience any of these issues, try a different size or fit variation.

Proper layering serves multiple functions: moisture management, temperature regulation, comfort, and additional protection. What you wear under your suit significantly impacts both fit and performance, so plan your layering system before finalizing your suit size.

Base layers are your foundation - worn directly against skin to manage moisture and regulate temperature. Never ride in cotton; it absorbs sweat and stays wet, causing chafing and temperature regulation issues.

Layer Type Material Best For Alpinestars Options

• Base layers should fit snugly against skin without bunching
• Flatlock seams prevent chafing during long sessions
• Long sleeves and full-length pants prevent suit leather from directly contacting skin
• Always wear the same base layers when fitting your suit

Alpinestars pioneered electronic airbag technology with Tech-Air®, the world's first fully autonomous motorcycle airbag system. Proper suit fit is critical for airbag deployment - the system inflates in milliseconds and must have specific tolerances to protect your collarbone, shoulders, ribs, and back effectively.

Tech-Air® systems are not one-size-fits-all. The airbag vest must fit your torso correctly, and your race suit must accommodate the vest without being overly tight or loose. Incorrect fit can prevent proper deployment or reduce protection coverage.

• Always size your suit while wearing your Tech-Air® vest
• Tech-Air® vests add approximately 1-2 sizes to your chest measurement
• Suit must allow 2-3 inches (5-7cm) of expansion room for airbag inflation
• Tech-Air® compatible suits feature specific internal construction to accommodate the airbag

The Tech-Air® 5 Plasma is an autonomous airbag vest designed to be worn under compatible race suits. It features AI-powered crash detection with sensors monitoring 1,000 times per second, deploying in 20–60 milliseconds when a crash is detected. The Plasma variant offers enhanced protection coverage with an upgraded airbag architecture for maximum safety performance.

Sizing Tech-Air® 5 Plasma:

• Available in sizes XS–3XL based on chest and height measurements
• Vest should fit snugly against your base layer – not loose or shifting
• Shoulder airbag chambers must align with your collarbone
• Back chamber should cover from neck base to lower back
• Front chest chamber should sit flat and centered across the sternum

Suit Compatibility: Once fitted with Tech-Air® 5 Plasma, try your race suit over the vest. The suit should feel snug but not restrictive. If the suit is too tight, size up – compressing the airbag prevents proper deployment. Due to the Plasma's expanded airbag volume, we recommend verifying compatibility with your suit manufacturer before use.

Born from MotoGP innovation, the Tech-Air® 10 v2 is optimized and engineered for track day use. Lightweight and slim, it delivers comprehensive full upper-body and hip protection, and now features user-replaceable gas inflators for enhanced versatility and practicality, as well as an all-new activation belt and integrated LED display for ease of use.

For Track Use: Some riders use Tech-Air® 10 v2 under race suits for additional versatility. Sizing considerations are similar to Tech-Air® 5 — the vest must fit your torso correctly, and the suit must accommodate it without compression.

Here's how to determine the right suit size when using Tech-Air®:

1. Fit the Tech-Air® vest first: Follow Tech-Air® sizing charts independently of your suit size
2. Wear your complete layering system: Base layer + chest protector (if using) + Tech-Air® vest
3. Measure your chest: With all layers on, measure around the fullest part of your chest
4. Add 2 inches (5cm) for deployment room: This ensures the suit doesn't restrict airbag inflation
5. Compare to sizing chart: Use your adjusted measurement to select suit size
6. Try on and test: Perform all fit checks in riding position; suit should feel snug but not tight
7. Check airbag clearance: In riding position, there should be slight room between suit and vest - not vacuum-tight

Alpinestars offers race suits specifically designed for Tech-Air® compatibility, featuring:

• Additional chest and shoulder room for airbag expansion
• Internal construction that doesn't restrict inflation
• Optimized fit that works with or without the airbag vest
• Designated models include the 1-Piece GP Tech V5 Leather Suit and the 1-Piece GP-R7 Leather Suit

Leather race suits require a break-in period of 3-5 track sessions (or approximately 200-300 miles of riding). During this time, the leather will conform to your body shape, stretch in high-stress areas, and become significantly more comfortable.

• First session: Suit will feel stiff, especially in shoulders, elbows, and knees. This is normal - leather needs stress cycles to soften
• Sessions 2-3: Noticeable improvement in flexibility; suit begins conforming to your body
• Sessions 4-5: Suit reaches optimal fit; leather has stretched 3-5% and molded to your shape
• After 10+ sessions: Fully broken in; maximum comfort and mobility

• Wear it at home: Spend 30-60 minutes in the suit doing stretches and movements
• Targeted stretching: Gently work stiff areas (knees, elbows) by repeatedly bending and extending
• Professional conditioning: Some riders use leather conditioner on non-critical areas (avoid armor zones)
• Heat cycling: Leather becomes more pliable when warm; wearing the suit in a warm environment can help

A new suit will feel restrictive - this doesn't necessarily mean it's too small. If the suit passes all fit checks (armor positioned correctly, no numbness, full range of motion possible even if stiff), the restriction you feel is likely normal break-in stiffness, not poor fit.

When to worry: If you cannot achieve full riding position, experience numbness, or armor is misaligned, the fit is wrong - stiffness won't fix these issues.

Even with careful measurement and fitting, you may encounter fit challenges. Here are the most common issues and how to address them:

Issue Cause Solution:

If you're struggling to achieve proper fit, visit an Alpinestars authorized dealer with expert fitting staff. They can:

• Assess your body proportions and recommend the best fit type
• Check armor positioning and make adjustments
• Identify whether issues are fit-related or normal break-in
• Recommend custom alterations if needed
• Ensure Tech-Air® compatibility if using airbag systems