KUROKO

Designed for tightening and loosening chainring bolts. Its 1mm width allows it to fit snugly into shallow grooves, providing excellent precision and workability.

KUROKO is a special tool used to tighten and loosen the bolts that secure the chainring and crank. When tightening or loosening the chainring bolts, KUROKO's two claws firmly grip the groove on the back of the chainring bolt to prevent it from rotating. 

Insert a 6mm hex wrench into the hex socket on the KUROKO. We recommend using a short head hex wrench, such as the RUNWELL STEX , as this handle provides stable operation. The protrusion in the middle acts as a guide, ensuring smooth installation. Because it is a screw type, if the protrusion becomes clogged and prevents installation, you can remove it by turning the protrusion.

The impetus for creating KUROKO came from customer feedback that conventional pressed tools had poor grip and were difficult to use. Because this is a process that requires high precision, we use NC lathe to machine out two claws that fit into the nut groove. Also, while conventional products have a flat-head nut groove that limits the orientation of the handle, KUROKO's handle (hex wrench) can be attached in any orientation at 60-degree intervals, allowing you to work in a comfortable position.

*KUROKO was developed based on the bolts that come with NJS-certified parts. It may not be as stable when used with commercially available nuts that have shallow grooves.