Bring your triathlon or time trial machine into the 12-speed era without replacing your existing levers, switches, junction box, battery holder, or callipers. This Shimano Ultegra R8150 Di2 Triathlon Upgrade Kit bundles every core drivetrain and electronic component you need to move from 10 or 11-speed Di2 to fully 12-speed performance — delivering faster, more precise shifts exactly when race pace demands it.

Highlights

• Upgrades 10 or 11-speed Di2 Tri/TT bikes to Shimano Ultegra R8150 12-speed Di2
• Reuses existing TT levers (ST-R8060 or equivalent), switches, junction box, battery holder, and callipers — minimising cost and install complexity
• RD-R8150 rear derailleur: 58% faster shifting than previous generation, single cage length covers 11-28 through 11-34 cassettes
• FD-R8150 front derailleur: 45% faster front shifting, 33% smaller frontal area, weight cut to 116 g
• FC-R8100 crankset: HOLLOWGLIDE structure with 52/36T or 50/34T options, crank lengths 160–175 mm
• CS-R8101 12-speed HYPERGLIDE+ cassette: smooth bi-directional shifts, compatible with 11-speed Shimano freehub bodies
• BT-DN300 internal Di2 battery: 52 g, 3.7 Wh, approximately 1,000 km average range
• Includes EW-SD300 wiring harness, EW-JC130 junction connector, EW-AD305 adaptor, and EW-EC300 USB-A charging cable

Drivetrain Upgrade

At the heart of the kit, the Ultegra RD-R8150 rear derailleur uses Shimano's latest Di2 platform with an integrated wireless unit, LED status indicator, and built-in charger port — all in a compact, single cage length that handles cassettes from 11-28T through 11-34T. The FD-R8150 front derailleur pairs HOLLOWGLIDE construction with the new road HYPERGLIDE+ chain system for seamless front shifts under load. The FC-R8100 crankset rounds out the drivetrain with HOLLOWTECH II axle technology and an exceptionally broad range of crank arm lengths (160, 165, 170, 172.5, and 175 mm), making it well suited to triathlete fit preferences and shorter-arm setups.

Electronic System & Battery

The BT-DN300 internal battery is cylindrical (Ø17 × 152 mm, 52 g) and integrates cleanly into the seat tube or frame interior of most triathlon and time trial bikes. Three EW-SD300 ports allow direct connection to both derailleurs, with the wiring harness included in the kit sized for typical TT aero-bar routing. Charging is via the EW-EC300 cable from any USB-A port through the rear derailleur connection point. In-house testing with the R8100/R8150 series confirms approximately 1,000 km average range per charge.

Cassette & Chain

The CS-R8101 12-speed cassette uses HYPERGLIDE+ technology to deliver equally smooth upshifts and downshifts even under power — a meaningful race advantage in transition or during surges. It remains compatible with standard Shimano HG 11-speed freehub bodies, meaning no rear-wheel change is typically required. The CN-M8100 12-speed chain with quick-link completes the drivetrain, designed for use across Shimano's 12-speed road and MTB platforms.

Compatibility & Fit

This kit is designed for triathlon and time trial bikes currently running Shimano Di2 10 or 11-speed electronic groupsets. It reuses your existing ST-R8060 (or compatible) TT brake/shift levers, aerobar switches, junction box, battery holder, and callipers. If your bike has been wired non-standardly, additional E-Tube components may be required. The FC-R8100 crankset requires a 24 mm HOLLOWTECH II-compatible bottom bracket (not included — specify for your frame shell standard). Front derailleur requires a band clamp or braze-on adapter to suit your frame; chain catcher compatibility should also be confirmed. If in doubt, bring your bike into Tune Cycles for a pre-install assessment.