Speed Pedal Wrench 8mm

The hex pedal wrench for MTB and traditional clipless

The 8 mm hex socket is the traditional pedal-spindle interface that dominated MTB clipless and road clipless designs before 6 mm sockets appeared on some road pedals. Shimano's hex-drive SPD MTB pedals (the PD-M540, PD-M770 and PD-M970 in Shimano's own service sheet; the PD-M520 and PD-M530 keep 15 mm flats) and a large installed base of clipless pedals use 8 mm hex. If a pedal does not have 15 mm wrench flats, the inboard hex will be 8 mm or 6 mm, and 8 mm is the size on Shimano's hex-drive SPD pedals.

The Speed Pedal Wrench is built for the install and removal extremes of that interface. The swivel handle locks at 90 degrees when the 35–55 N·m install torque Shimano publishes for its SPD pedals needs every centimetre of lever arm, and locks at 0 degrees when the pedal is threading through its travel and the mechanic wants to spin it fast.

Why an 8 mm hex pedal needs a different wrench than a regular Allen key

A standard 8 mm L-shaped Allen key reaches the hex from behind the crank arm, but it has to clear the frame to swing through. On most bikes the long arm hits the chainstay; the mechanic flips to the short arm and loses two-thirds of the leverage at the install-torque extreme.

The swivel handle removes the geometry problem. The handle rotates to clear the frame, then locks rigid for the high-torque moment. The lock takes the install spec without giving back any of the lever arm a standard wrench gives up at the frame.

Compatibility

Fits any pedal with an 8 mm hex socket at the inboard end of the spindle. This is the volume standard for MTB clipless (Shimano's hex-drive SPD pedals, PD-M540 and up), traditional road clipless designs, and the broader installed base of hex-engagement pedals. Some clipless pedals use a 6 mm hex instead; see the Speed Pedal Wrench 6mm variant. Pedals with 15 mm wrench flats are best served by the Pro Pedal Wrench or home Pedal Wrench.

Specs

• Engagement: 8 mm hex bit
• Handle: Swivel handle, 0° / 90° lockable positions; 233 mm overall, 28 × 24 mm head, 200 g
• Material: Premium flex chrome-vanadium steel, drop-forged body, hardened and tempered
• Finish: Trivalent chrome plated per ISO 1456:2009
• Standard: Manufactured per ISO 3315
• Grip: Ergonomic two-component handle
• SKU: 629454 (Unior article 1613S/1BI, 8 mm size; the 6 mm size is 629453)

Built in Zreče, Slovenia

Unior has been forging hand tools in Zreče since 1919, and sponsors professional road and mountain-bike race teams. The 8 mm hex bit sees the most cyclic stress on this wrench. Hardened-and-tempered chrome-vanadium drop-forged from the Zreče works gives the bit the wear resistance to hold its profile across thousands of install cycles; a stamped bit at this size rounds out long before a forged one does.

Pro tip from our mechanics

Service rigs and home shops that work on MTB volume need an 8 mm hex pedal wrench within reach. Once the threads are clean and anti-seized, the swivel handle is the difference between a pedal swap that takes two minutes and one that takes ten. Our pedal guide covers the install procedure, the removal sequence, and how to spot a stripped thread before the wrench finds it: How to install and remove bike pedals →

FAQ

Which pedals does the 8 mm Speed Pedal Wrench fit, and when do I need the 6 mm version? It fits any pedal with an 8 mm hex socket at the inboard end of the spindle. Shimano's own service sheet specifies an 8 mm Allen key for its hex-drive SPD pedals (PD-M540, PD-M770, PD-M970) and a 15 mm spanner for the PD-M520 and PD-M530. Unior makes the 1613S/1BI in 8 mm (code 629454) and 6 mm (code 629453); if your pedal's socket takes a 6 mm key, you need the 6 mm Speed Pedal Wrench.

How does the swivel head on the Speed Pedal Wrench work? The bit sits in a forked pivot at the end of the shaft. Set the handle at 90 degrees to the bit and you have a 233 mm lever for the install torque and for breaking a pedal loose; swing it straight in line with the bit and the wrench spins like a screwdriver through the rest of the thread. Because the handle can angle away from the frame, the bit stays square in the hex behind the crank arm where an L-shaped key runs into the chainstay.

How long is the Speed Pedal Wrench, what does it weigh, and what is it made of? Unior's datasheet lists the 1613S/1BI at 233 mm long with a 28 mm wide, 24 mm high head. The 8 mm version (code 629454) weighs 200 g and the 6 mm version (code 629453) 190 g. The body is drop-forged premium flex chrome-vanadium steel, hardened and tempered, trivalent chrome plated to ISO 1456:2009 and made to ISO 3315, with a heavy-duty two-component handle.

What is the difference between the Speed Pedal Wrench and the Pro Pedal Wrench 1613/2BI? The Pro Pedal Wrench 1613/2BI is a 350 mm wrench with two offset 15 mm openings for pedals that have wrench flats on the spindle. The Speed Pedal Wrench 1613S/1BI drives the hex socket in the end of the spindle instead, with an 8 mm (or 6 mm) bit on a 233 mm swivel-head shaft. Pedals with 15 mm flats take the 1613/2BI; pedals with only an inboard hex take this one.