Bosch Gen4 motor mounts take Torx Plus, and the set's T40 Torx Plus socket is sized for them; a standard T40 engages but rounds the recess at motor-mount torque. The rest of the 49-piece spread runs 1/4-inch drive for stem and rotor bolts up to 1/2-inch for pedal axles and crank bolts, made to ISO 2725-1 and ISO 3315.
Out of stock
Couldn't load pickup availability
Forged in Zreče, Slovenia since 1919. Official technical partner of multiple World Tour and downhill teams.
In the box
-
11× Socket 1/4", 6 point 188/2 6p
-
5× Socket 1/2", 6 point 190/1 6p
-
5× Hex socket 1/4" 187/2HX
-
5× Hex socket 1/2" 192/2HX
-
6× Long hex socket 1/2" 192/2HXL
-
8× Screwdriver socket with TX profile 1/4" 187/2TX
-
2× Long screwdriver socket 1/2" with TX profile 192/2TXL
-
Adaptor 1/4" 188.7/2
-
Adaptor 1/2" 190.7/2
-
Reversible ratchet 1/4" 188.1/1ABI-US
-
Reversible ratchet 1/2" 190.1/1ABI-US
-
Metal box 981K1/2R
On this page
A modern bicycle uses more fastener types than any other consumer-grade machine. Hex, Torx, Torx Plus on Bosch e-bike mounts, 1/4" sockets at low torque, 1/2" sockets at higher torque for pedal-wrench and crank-bolt work, BB sockets, the lockring sockets the cassette runs on. A bits and sockets set is the workshop investment that converts that fastener inventory from a per-job purchase into a one-shelf reference.
The Master Bits and Sockets Set carries 49 pieces sized to the fastener spread a current bike runs on, in a durable sheet-steel case ready for shop-bench storage. Crafted in Europe to ISO 2725-1 and ISO 3315 dimensional standards, which is the spec language that distinguishes a precision sockets set from a generic one.
What is in the set
The 49-piece selection covers 1/4" and 1/2" ratchet-driver compatibility across the bike-fastener spread, plus the Torx Plus profile for Bosch e-bike Gen4 motor mounts:
- 1/4" drive sockets and bits: sized to the low-torque fasteners on a modern bike (stem bolts, derailleur bolts, brake-caliper mount bolts, rotor bolts, accessory mounts).
- 1/2" drive sockets: sized to the higher-torque fasteners (pedal axles, crank bolts, larger BB sockets).
- Hex bits: standard metric sizes for the recess profiles on current groupset and component fasteners.
- Torx bits: standard metric sizes for the Torx recesses on rotor bolts, stem bolts, and groupset fasteners.
- T40 Torx Plus: sized to the Bosch e-bike Gen4 motor-mount bolts, which use the Torx Plus profile rather than standard Torx. A standard Torx T40 driver will engage a Torx Plus T40 recess, but at the high working torque a motor mount sees, the smaller contact patch on a standard Torx tip will round the recess. The Torx Plus socket is the correct fit.
Why the ISO numbers matter
ISO 2725-1 and ISO 3315 are the dimensional standards that publish the square-drive geometry and the hex-flat tolerances a sockets set must hold. A set built to these standards interchanges with other ISO-compliant ratchets, adapters, and bit holders without geometry slop; a non-compliant set fits its own ratchet but rounds out in third-party tools.
Specs
- 49 piece sockets and bits set
- 1/4" and 1/2" ratchet-driver compatibility
- Sheet-steel case for storage and transport
- SOS foam tray for tool retention
- ISO 2725-1 and ISO 3315 dimensional standards
- Ergonomic double-component handles for secure grip
The 49-piece bits-and-sockets selection and its sheet-steel storage case are itemized in the In the box list below.
Built in Zreče, Slovenia
Unior has been forging hand tools in Zreče, Slovenia, since 1919, and is the official technical partner of multiple World Tour and downhill teams. The Master Bits and Sockets Set is the everyday small-fastener reference on a working shop bench; the Torx Plus inclusion is the spec the Bosch Gen4 e-bike installed base specifically needs.
Pro tip from our mechanics
A bits and sockets set lives on the bench longer than most workshop purchases because every job touches it. The smaller 1/4" Socket Set 188BI6P15 is the right entry point for a home shop just starting; the Master Bits and Sockets Set is the destination set once the workshop runs every bike fastener size. Pair with a slipper torque wrench for torque control across the fastener spread.
Tech Tips
How to choose the right bike tool kit
