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 sponsors professional road and mountain-bike race 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 →.