30T × 52T · climber's ring
MTB 30T · 10-52, lowest gear
Narrow-wide on SRAM's 94 × 4, in the cassette's lowest gear.

Narrow-wide, 104 × 4, with four bolt lugs.
Using the CheapCAD Tools connector, design a two-sprocket drive in Sprocket Designer on 12sp (12-speed bicycle) roller chain, about 435 mm between centres. Sprocket 1: 32 teeth, a chainring; a 104 mm bolt circle (BCD) with 4 bolts; narrow-wide teeth; spokes: the web cut to bolt tabs, Rim Depth 10 mm, Tab Wall ×2 12 mm; no tooth chamfer. Sprocket 2: 52 teeth, a cog; an ISO 14 straight-sided spline bore: 9 splines, minor diameter 32.5 mm, major 34.75 mm, width 6.25 mm, one key slot 3.25 mm wide (the Shimano HG cassette spline); spokes: tapered spokes, 6 of them, Hub OD 76 mm, Rim Depth 18 mm, Width at Rim 32 mm, Width at Hub 26 mm, Angle Offset 12°; no tooth chamfer. Check the design, apply any Auto-fix it suggests, then export both sprockets as STL and give me the download link.
Paste it into Claude, ChatGPT or any AI app with the CheapCAD Tools connector, and it designs this drive with you, checks it and hands you the files. How to connect your AI.
The link opens both sprockets and the chain in the Sprocket Designer's 3D Mode. Change the teeth, bore, hub or spokes, then download STL, STEP, DXF or SVG. Strength figures are the app's plane-stress check of each sprocket in the material it names; SF is the safety factor.
MTB 30T · 10-52, lowest gear
Narrow-wide on SRAM's 94 × 4, in the cassette's lowest gear.
BMX street 25/9
The straight five-spoke street sprocket, after BSD's Guard.