Home mechanics and workshops working on Shimano cranksets and chainrings.
The Shimano TL-FC21 is a double-ended peg spanner. The 3-claw end grips the slotted chainring fixing nut on the back of the crank so it does not spin while you undo or tighten the chainring bolt.
The 2-claw end fits the crank cap on Shimano Hollowtech II cranks with a one-key release, for setting preload when you fit the left crank. It is made from hardened steel, is 133 mm long for better leverage, and the hex holes double as a 9 mm and 10 mm wrench.
Chainring nut holder
3-claw end stops slotted chainring nuts spinning.
Crank cap tool
2-claw end fits Shimano one-key release crank caps.
Better leverage
133 mm long, 30 mm longer than the old TL-FC20.
Hardened steel
Rigid and built to last in the workshop.
Tool
Uses
Great for
Maybe not for
Suits slotted chainring nuts and Shimano one-key release crank caps. Pair it with a 5 mm hex key for chainring bolts.
Crank cap is not a clamp
The crank cap only sets bearing preload. Snug it until the play is gone, then tighten the pinch bolts. Over-tightening the cap makes the cranks stiff to turn.
Grease the chainring bolts
A touch of grease on the chainring bolt threads stops them seizing and makes next time much easier.
The workshop standard for over a century.
Shimano started as a small ironworks in Sakai, Japan in 1921 and grew into the world's biggest maker of bicycle components.
Alongside its groupsets, Shimano makes the dedicated service tools its own parts are designed around, which is why so many workshops keep a drawer of blue-and-grey TL tools.
