CYCLING
Interactive Engineering Engine

DRIVETRAIN CALCULATOR

Interconnected gear ratio, gear inches, development distance per pedal revolution, speed, gain ratio, skid patch, and chain length system.

Gear RatioGear InchesDevelopmentGain RatioSpeedCadenceSkid PatchesChain Length
Quick Starting Presets:

1. Drivetrain Setup

Chainrings & Cassette
Known Cranksets:

2. Wheel & Tire Model

Dimensions & Rollout

Calculated wheel dimensions are theoretical estimates. Actual rollout varies with tire pressure, rim inner width, and rider weight. Use measured rollout for highest accuracy.

3. Rider & Crank Inputs

Cadence & Ergonomics
90 RPM
40 RPM (Climbing)90 RPM (Ideal)140 RPM (Sprinting)
172.5 mm
150 mm180 mm

Crank length is used to calculate Gain Ratio, measuring leverage based on pedal stroke radius relative to wheel radius. It does not change mechanical gear ratio, gear inches, development distance, or wheel rollout.

Drivetrain Summary

Live Calculated
Total Range455%4.55× Gearing
Lowest Gear34×3426.7" / 2.14m
Highest Gear50×11121.3" / 9.71m
Total Combinations24Gears in system
Unique Ratios240 duplicate overlap

Gear Matrix

Chainrings (rows) vs Sprockets (columns). Color scale indicates range from lowest to highest.

Chainring \ Rear Cog11T12T13T14T15T17T19T21T24T28T32T34T
50T121.3"111.2"102.7"95.3"89.0"78.5"70.2"63.6"55.6"47.7"41.7"39.3"
34T82.5"75.6"69.8"64.8"60.5"53.4"47.8"43.2"37.8"32.4"28.4"26.7"
Range scale:Lowest→Mid→Highest
Orange dot = Duplicate or Near-duplicate gear ratio

Gear Table

Comprehensive sorted breakdown for every chainring x cassette sprocket combination

24 Total Gear Combinations
GearCombination
Ratio
Gear Inches
Development
Gain Ratio
Jump %
Speed (@90rpm)
Status
134T × 34T1.00 : 126.7"2.14 m1.97-11.5 km/h (7.2 mph)Unique
234T × 32T1.06 : 128.4"2.27 m2.09+6.3%12.3 km/h (7.6 mph)Unique
334T × 28T1.21 : 132.4"2.59 m2.39+14.3%14.0 km/h (8.7 mph)Unique
434T × 24T1.42 : 137.8"3.03 m2.78+16.7%16.3 km/h (10.2 mph)Unique
550T × 34T1.47 : 139.3"3.14 m2.89+3.8%17.0 km/h (10.5 mph)Unique
650T × 32T1.56 : 141.7"3.34 m3.07+6.3%18.0 km/h (11.2 mph)Unique
734T × 21T1.62 : 143.2"3.46 m3.18+3.6%18.7 km/h (11.6 mph)Unique
850T × 28T1.79 : 147.7"3.81 m3.51+10.3%20.6 km/h (12.8 mph)Near (1%)
934T × 19T1.79 : 147.8"3.82 m3.52+0.2%20.6 km/h (12.8 mph)Near (1%)
1034T × 17T2.00 : 153.4"4.27 m3.93+11.8%23.1 km/h (14.3 mph)Unique
1150T × 24T2.08 : 155.6"4.45 m4.09+4.2%24.0 km/h (14.9 mph)Unique
1234T × 15T2.27 : 160.5"4.84 m4.45+8.8%26.1 km/h (16.2 mph)Unique
1350T × 21T2.38 : 163.6"5.09 m4.68+5.0%27.5 km/h (17.1 mph)Near (2%)
1434T × 14T2.43 : 164.8"5.19 m4.77+2.0%28.0 km/h (17.4 mph)Near (2%)
1534T × 13T2.62 : 169.8"5.59 m5.14+7.7%30.2 km/h (18.7 mph)Near (1%)
1650T × 19T2.63 : 170.2"5.62 m5.17+0.6%30.4 km/h (18.9 mph)Near (1%)
1734T × 12T2.83 : 175.6"6.05 m5.57+7.7%32.7 km/h (20.3 mph)Unique
1850T × 17T2.94 : 178.5"6.28 m5.78+3.8%33.9 km/h (21.1 mph)Unique
1934T × 11T3.09 : 182.5"6.60 m6.07+5.1%35.7 km/h (22.2 mph)Unique
2050T × 15T3.33 : 189.0"7.12 m6.55+7.8%38.4 km/h (23.9 mph)Unique
2150T × 14T3.57 : 195.3"7.63 m7.02+7.1%41.2 km/h (25.6 mph)Unique
2250T × 13T3.85 : 1102.7"8.22 m7.56+7.7%44.4 km/h (27.6 mph)Unique
2350T × 12T4.17 : 1111.2"8.90 m8.19+8.3%48.1 km/h (29.9 mph)Unique
2450T × 11T4.55 : 1121.3"9.71 m8.93+9.1%52.4 km/h (32.6 mph)Unique

Performance Visualizations

Speed curves across cadence ranges and overall gearing envelope

Gear CombinationRatio60 RPM70 RPM80 RPM90 RPM100 RPM110 RPM120 RPM
34T × 34T1.007.7 km/h9.0 km/h10.3 km/h11.5 km/h12.8 km/h14.1 km/h15.4 km/h
34T × 32T1.068.2 km/h9.5 km/h10.9 km/h12.3 km/h13.6 km/h15.0 km/h16.3 km/h
34T × 28T1.219.3 km/h10.9 km/h12.4 km/h14.0 km/h15.6 km/h17.1 km/h18.7 km/h
34T × 24T1.4210.9 km/h12.7 km/h14.5 km/h16.3 km/h18.2 km/h20.0 km/h21.8 km/h
50T × 34T1.4711.3 km/h13.2 km/h15.1 km/h17.0 km/h18.8 km/h20.7 km/h22.6 km/h
50T × 32T1.5612.0 km/h14.0 km/h16.0 km/h18.0 km/h20.0 km/h22.0 km/h24.0 km/h
34T × 21T1.6212.4 km/h14.5 km/h16.6 km/h18.7 km/h20.7 km/h22.8 km/h24.9 km/h
50T × 28T1.7913.7 km/h16.0 km/h18.3 km/h20.6 km/h22.9 km/h25.2 km/h27.5 km/h
34T × 19T1.7913.8 km/h16.1 km/h18.3 km/h20.6 km/h22.9 km/h25.2 km/h27.5 km/h
34T × 17T2.0015.4 km/h17.9 km/h20.5 km/h23.1 km/h25.6 km/h28.2 km/h30.8 km/h
50T × 24T2.0816.0 km/h18.7 km/h21.4 km/h24.0 km/h26.7 km/h29.4 km/h32.0 km/h
34T × 15T2.2717.4 km/h20.3 km/h23.2 km/h26.1 km/h29.0 km/h32.0 km/h34.9 km/h
50T × 21T2.3818.3 km/h21.4 km/h24.4 km/h27.5 km/h30.5 km/h33.6 km/h36.6 km/h
34T × 14T2.4318.7 km/h21.8 km/h24.9 km/h28.0 km/h31.1 km/h34.2 km/h37.3 km/h
34T × 13T2.6220.1 km/h23.5 km/h26.8 km/h30.2 km/h33.5 km/h36.9 km/h40.2 km/h
50T × 19T2.6320.2 km/h23.6 km/h27.0 km/h30.4 km/h33.7 km/h37.1 km/h40.5 km/h
34T × 12T2.8321.8 km/h25.4 km/h29.0 km/h32.7 km/h36.3 km/h39.9 km/h43.6 km/h
50T × 17T2.9422.6 km/h26.4 km/h30.2 km/h33.9 km/h37.7 km/h41.5 km/h45.2 km/h
34T × 11T3.0923.8 km/h27.7 km/h31.7 km/h35.7 km/h39.6 km/h43.6 km/h47.5 km/h
50T × 15T3.3325.6 km/h29.9 km/h34.2 km/h38.4 km/h42.7 km/h47.0 km/h51.3 km/h
50T × 14T3.5727.5 km/h32.0 km/h36.6 km/h41.2 km/h45.8 km/h50.3 km/h54.9 km/h
50T × 13T3.8529.6 km/h34.5 km/h39.4 km/h44.4 km/h49.3 km/h54.2 km/h59.2 km/h
50T × 12T4.1732.0 km/h37.4 km/h42.7 km/h48.1 km/h53.4 km/h58.7 km/h64.1 km/h
50T × 11T4.5535.0 km/h40.8 km/h46.6 km/h52.4 km/h58.3 km/h64.1 km/h69.9 km/h
Track / Fixed GearFixed Gearing

Skid Patch Analysis

For fixed-gear bikes, calculate rear tire wear locations during skid stopping for 50T × 11T.

Single-Foot Skid11 Patches
Ambidextrous Skid11 Patches
More skid patches distribute tire casing wear evenly.
Chain SizingGeometry

Chain Length Calculator

Exact Calculated Links:80.82
Recommended Even Links:82 Links
Round up to nearest even link count when sizing new chains.
Shareable SetupURL Sync

Share Drivetrain Setup

Export your current drivetrain configuration, wheel dimensions, and cadence setup directly into a shareable URL.