What is Anti-Rise?
When you grab the brakes, weight transfers forward. The rear suspension wants to extend — Anti-Rise is the percentage of that extension the linkage counteracts.
Anti-Rise describes how much the rear suspension linkage resists the tendency of the rear end to rise (extend) when the bike decelerates. Under braking, inertia shifts mass forward, unloading the rear wheel. Without any Anti-Rise, the rear shock would extend rapidly, reducing rear-wheel traction exactly when you need it most.
A well-tuned Anti-Rise curve keeps the rear wheel tracking the ground through braking bumps and into corners, maintaining grip and chassis stability. Too much and the rear feels harsh and locked; too little and the bike dives and loses rear traction.
The Physics of Braking
Anti-Rise exists because braking creates a torque around the rear axle that fights the suspension's natural compression.
When you apply the brakes, deceleration creates a forward weight transfer. The rear wheel carries less load, so the rear shock extends. But braking also generates a torque on the rear wheel — and depending on where the brake caliper is mounted and how the linkage pivots are arranged, that torque can either help or hinder the extension.
The key is the brake torque line: an imaginary line drawn from the rear axle to the point where the brake caliper's reaction force acts on the swingarm. If this line passes above the main pivot, braking torque compresses the suspension (high Anti-Rise). If it passes below, braking torque extends it (low Anti-Rise).
- 1Brake mounted on the chainstay → Anti-Rise is typically higher
- 2Brake mounted on the seatstay → Anti-Rise is typically lower
- 3Floating brake caliper → Anti-Rise can be tuned independently of pivot geometry
How Anti-Rise is Calculated
Anti-Rise is the ratio of the brake-induced torque that counteracts extension to the total extension torque from weight transfer.
To calculate Anti-Rise, you need three things: the instantaneous centre (IC) of the rear linkage, the brake torque line, and the system's center of gravity (D_COG). The percentage tells you how much of the brake-transfer rise is cancelled by the linkage geometry.
Anti-Rise (%) = (T_brake / T_transfer) × 100T_brake = brake torque about rear axle · T_transfer = weight transfer torque about rear contact patch
The brake torque is found by drawing a line from the rear axle to the brake caliper mount, then finding where it intersects the line from the main pivot to the IC. The vertical distance of that intersection relative to D_COG determines the effective Anti-Rise percentage.
Interpreting Anti-Rise Values
Different riding styles and terrain call for different Anti-Rise characteristics.
- 1Very low (0–20%): Rear extends freely under braking. Good for pure traction on rough terrain, but can feel unstable under hard braking.
- 2Low–moderate (20–50%): Balanced feel. Rear stays compliant but rises slightly, keeping the bike level. Common on trail and enduro bikes.
- 3Moderate–high (50–80%): Rear resists rise noticeably. Chassis stays flatter under braking, good for steep technical descents.
- 4High (>80%): Rear nearly locked under braking. Can feel harsh on bumps; sacrifices small-bump traction for stability.
Most modern mountain bikes aim for an Anti-Rise curve that starts moderate (40–60%) in the sag zone and gradually decreases as the suspension goes deeper into travel. This keeps the rear planted at the top of the stroke for traction, while allowing some rise deeper in the stroke to absorb large braking bumps.
Design Considerations
Frame designers balance Anti-Rise against Anti-Squat, leverage ratio, and pedalling efficiency — you can't optimise one in isolation.
Anti-Rise and Anti-Squat often pull in opposite directions. A linkage that resists squat under power (high Anti-Squat, good for climbing) may also resist rise under braking (high Anti-Rise, which may feel harsh). Designers must find a compromise that suits the bike's intended use.
- 1Cross-country bikes often prioritise Anti-Squat over Anti-Rise — climbing efficiency matters more than braking traction.
- 2Enduro and downhill bikes aim for a balanced Anti-Rise curve — braking traction and stability are critical.
- 3Floating brake designs decouple Anti-Rise from Anti-Squat, allowing independent tuning — at the cost of complexity and weight.
- 4The instant centre position at sag is the single biggest lever for adjusting both Anti-Rise and Anti-Squat.
Anti-Rise in BikeSPEZL
The R&D module calculates Anti-Rise live as you adjust pivot positions, sag, and D_COG.
In BikeSPEZL's Ride Dynamics simulation, Anti-Rise is computed from your KinematicDesign's pivot points, the brake mount position, and the D_COG calculated from your rider scan, bike build, and gear set. As you move a pivot or change sag, the Anti-Rise curve updates in real time, showing exactly how your design choices affect braking behaviour.