The Bosch Purion 400 Retrofit Kit (BHU3500) Ñ 31.8 mm is the complete package for fitting the Purion 400 display to Smart System e-bikes with 31.8 mm diameter handlebars. Includes the display, bracket, and all hardware needed for a clean first-time install.

What's Included

• Purion 400 display (BHU3500) Ñ 1.6" rugged colour LCD
• 31.8 mm handlebar clamp for the display mount
• All required installation hardware
• Customisable via the Bosch eBike Flow app

Key Features

• Compact, impact-resistant display Ñ tucks safely into the handlebar triangle
• Splash- and dust-protected for all-weather riding
• Wired connection Ñ no Bluetooth pairing needed for core function
• eBike Flow app connectivity for settings and firmware updates

Compatibility

Compatible with all Bosch Smart System (BES3) motors except the Speed variant BDU3781. Requires a 31.8 mm handlebar clamp area Ñ most road, trekking, and hybrid e-bikes use this size. Measure before ordering or see the 35.0 mm version if your bar is wider (common on modern eMTBs).

Ideal For

Riders upgrading from no display or a different Smart System display who want a compact, rugged cockpit. Particularly popular for conversion of newly-built e-bikes and for replacing a damaged display along with its mount in one order. Professional install recommended for Smart System pairing. Genuine Bosch OE, warranty-backed, same-day dispatch.