Shimano Ultegra CS-R8101 Cassette - 12-Speed | 11-34t
What Is the Shimano Ultegra CS-R8101 12-Speed 11-34t and Who Is It For?
The CS-R8101 11-34t is Shimano's wide-range option in the 12-speed Ultegra cassette lineup, pairing the close-ratio mid-gear density of a 12-speed drivetrain with a 34t low cog that covers serious climbing without requiring the weight or bulk of an MTB cassette. Like the 11-30t variant, it uses Hyperglide+ bidirectional shifting technology with individually optimized ramp and pin placement per cog for fast, load-tolerant upshifts and downshifts in both directions. The cassette is built with larger-diameter driving cogs that allow it to seat on both existing Shimano 11-speed HG road freehub bodies and the newer 12-speed freehub standard, giving riders upgrading from an 11-speed drivetrain a clear compatibility path without needing to replace hub internals. The additional 12th cog spreads the range between 11t and 34t across one more step compared to an 11-speed equivalent, reducing the jump size between cogs in the critical mid-range climbing gears where cadence consistency matters most on steep terrain.
The 11-34t range suits hilly road riding, gran fondo, and mixed terrain use where the 34t low cog provides a genuine bail-out gear for sustained steep pitches while the top-end 11t cog maintains flat road and descent performance. It requires a rear derailleur with sufficient cage capacity to handle 34t, such as the Ultegra RD-R8150 Di2 or a compatible long cage rear derailleur. The cassette uses Shimano 12-speed road chains and pairs with R8100-series Ultegra or R9200-series Dura-Ace components. For riders on mixed terrain who want the full benefit of 12-speed gear density without sacrificing climbing range, the CS-R8101 11-34t is the correct wide-range specification.
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Shimano Ultegra CS-R8101 Cassette - 12-Speed | 11-34t
Shimano Ultegra CS-R8101 Cassette - 12-Speed | 11-34t
What Is the Shimano Ultegra CS-R8101 12-Speed 11-34t and Who Is It For?
The CS-R8101 11-34t is Shimano's wide-range option in the 12-speed Ultegra cassette lineup, pairing the close-ratio mid-gear density of a 12-speed drivetrain with a 34t low cog that covers serious climbing without requiring the weight or bulk of an MTB cassette. Like the 11-30t variant, it uses Hyperglide+ bidirectional shifting technology with individually optimized ramp and pin placement per cog for fast, load-tolerant upshifts and downshifts in both directions. The cassette is built with larger-diameter driving cogs that allow it to seat on both existing Shimano 11-speed HG road freehub bodies and the newer 12-speed freehub standard, giving riders upgrading from an 11-speed drivetrain a clear compatibility path without needing to replace hub internals. The additional 12th cog spreads the range between 11t and 34t across one more step compared to an 11-speed equivalent, reducing the jump size between cogs in the critical mid-range climbing gears where cadence consistency matters most on steep terrain.
The 11-34t range suits hilly road riding, gran fondo, and mixed terrain use where the 34t low cog provides a genuine bail-out gear for sustained steep pitches while the top-end 11t cog maintains flat road and descent performance. It requires a rear derailleur with sufficient cage capacity to handle 34t, such as the Ultegra RD-R8150 Di2 or a compatible long cage rear derailleur. The cassette uses Shimano 12-speed road chains and pairs with R8100-series Ultegra or R9200-series Dura-Ace components. For riders on mixed terrain who want the full benefit of 12-speed gear density without sacrificing climbing range, the CS-R8101 11-34t is the correct wide-range specification.
Original: $117.99
-70%$117.99
$35.40Product Information
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Description
What Is the Shimano Ultegra CS-R8101 12-Speed 11-34t and Who Is It For?
The CS-R8101 11-34t is Shimano's wide-range option in the 12-speed Ultegra cassette lineup, pairing the close-ratio mid-gear density of a 12-speed drivetrain with a 34t low cog that covers serious climbing without requiring the weight or bulk of an MTB cassette. Like the 11-30t variant, it uses Hyperglide+ bidirectional shifting technology with individually optimized ramp and pin placement per cog for fast, load-tolerant upshifts and downshifts in both directions. The cassette is built with larger-diameter driving cogs that allow it to seat on both existing Shimano 11-speed HG road freehub bodies and the newer 12-speed freehub standard, giving riders upgrading from an 11-speed drivetrain a clear compatibility path without needing to replace hub internals. The additional 12th cog spreads the range between 11t and 34t across one more step compared to an 11-speed equivalent, reducing the jump size between cogs in the critical mid-range climbing gears where cadence consistency matters most on steep terrain.
The 11-34t range suits hilly road riding, gran fondo, and mixed terrain use where the 34t low cog provides a genuine bail-out gear for sustained steep pitches while the top-end 11t cog maintains flat road and descent performance. It requires a rear derailleur with sufficient cage capacity to handle 34t, such as the Ultegra RD-R8150 Di2 or a compatible long cage rear derailleur. The cassette uses Shimano 12-speed road chains and pairs with R8100-series Ultegra or R9200-series Dura-Ace components. For riders on mixed terrain who want the full benefit of 12-speed gear density without sacrificing climbing range, the CS-R8101 11-34t is the correct wide-range specification.
