Sample · Road 50/34 · 11-28, lowest gear

34 × 28 · compact lowest gear

The inner ring on the 11-28's biggest cog.

Road34 : 28

Build it with your AI

Using the CheapCAD Tools connector, design a two-sprocket drive in Sprocket Designer on 11sp (11-speed bicycle) roller chain, about 410 mm between centres. Sprocket 1: 34 teeth, a chainring; a 110 mm bolt circle (BCD) with 4 bolts in the shimano pattern; a 95.8 mm centre opening; no tooth chamfer. Sprocket 2: 28 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); 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.

What's in this design

Sprocket 1 · 34 teeth

34T · 11-speed · chainring · 110 BCD × 4 Shimano
191 MPa peak · SF 2.63 in 7075 · rim moves 0.12 mm · 2.05 mm plate · 41 % solid

Sprocket 2 · 28 teeth

28T · 11-speed · cassette cog · Shimano HG spline
189 MPa peak · SF 2.67 in 7075 · rim moves 0.25 mm · 1.60 mm plate · 77 % solid

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.

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