Crank Cap Tool Metal

The dedicated tool for Shimano Hollowtech II preload caps. Wavy star-shape profile machined into the head to engage the plastic preload cap on the non-drive crank arm; integrated magnetic backing so the tool stores against any steel bench surface and stays out of the way; a 13 mm hex shoulder lets you drive the cap with a 13 mm wrench when hand-turning isn't enough.

Shimano's preload cap is the small plastic adjuster that sets the side-to-side preload on the bottom bracket bearings. Loose, the cranks have axial play; tight, the bearings drag. The cap is hand-tight in spec; you don't need a torque wrench, just a clean engagement and enough thread depth to set the cup against the spindle. The 1609.1/2 is the engagement tool that lets you set that preload cleanly the first time.

Why the metal version

The plastic-bodied crank cap tools that ship with mid-range tool kits work for occasional use, but the engagement surface wears faster than a metal-bodied tool's. After enough preload cap turns, a plastic tool starts to round on the wavy-star contact points; from there, the tool slips on the cap and the cap's plastic gets chewed. The metal-bodied tool keeps its tip-to-cap tolerance across years of bench use.

The magnetic backing is the always-on-hand convenience: the tool stores against the bench's vise body or against a workshop wall panel without dropping into the parts drawer. For a shop that does multiple BB services a day, the storage option saves the time of pawing through a drawer for the right tool.

Compatibility

• Shimano Hollowtech II preload caps (the plastic adjuster on the non-drive crank arm)
• 13 mm hex shoulder for wrench-driven adjustment when hand-tight isn't enough
• Most Shimano cranksets from 2003 onward use the Hollowtech II preload pattern

Specs

• Engagement: wavy star profile matched to Shimano Hollowtech II preload caps
• Body: metal (chrome-plated)
• Backing: integrated magnet
• Drive option: 13 mm hex shoulder
• SKU: 1609.1/2 (623120)

Built in Zreče, Slovenia

Unior has been forging hand tools in Zreče since 1919, and is the official technical partner of multiple World Tour and downhill teams. The 1609 line covers crank-cap tools for multiple BB platforms; the 1609.1/2 for Shimano Hollowtech II, and dedicated variants for SRAM DUB and the proprietary Race Face / Cinch system. The metal-bodied engagement is what differentiates the workshop-grade line from the plastic-bodied entry-level tools.

Pro tip from our mechanics

Set the preload cap by hand whenever possible; only reach for the 13 mm wrench shoulder when hand-tight isn't enough. The preload value is on the light side of the torque curve; overtightening with a wrench can crush the bearing race against the cup and introduce drag that wasn't there before. Hand-tight + a quarter-turn for security is the working spec.

For the broader procedure on cleaning and replacing a Hollowtech II bottom bracket, including the preload-cap step: Replace or clean your Hollowtech II Bottom Bracket →.