Tag Archives: tool

The 4th Hand Tool

Sounds out of this world from the fourth dimension, doesn’t it?


In many circles, this tool is also called the Cable Stretcher but “4th Hand Tool” is its more common moniker. This tool handily pulls the cables for the derailleurs (the shifters) and brakes in order to free up a hand of your own to tighten nuts and bolts. As one reviewer on Amazon writes, “When your bro’s paw is wrapped around a cold one and you need another hand…,” essentially this tool gives you the extra hand you need when you need to tighten a cable. I especially find that this tool offers me the strength that my simple tug won’t deliver to make my brake tension that much more responsive.

While the handle is loose, slide the cable through the grooves at the top with the flattened arm butted against the brake or derailleur (the part that shift your chain). When you clamp the handles, the tool grabs the cable and pushes off the brake or derailleur, pulling the cable taut. While one hand holds that tool, the other is then free to tighten the nuts or bolts to lock the cable down. There is a handy little video where you can see the clamping and pulling action of the tool on eHow.

Combination Wrenches


A set of chrome-vanadium metric wrenches, open at one end, box/ring at the other. This type is commonly known as a “combination” wrench.

Fixed Wrenches are made of a single piece of metal, and only fit specific sizes of fasteners.

Combination wrenches, like the picture above, are chrome double-ended wrenches with an open end and a box end that are the same size bolt on each end. This is the most useful and most common general-purpose wrench style. The box end tends to be stronger that the open end and are the best side to use for high torque uses, because it can contact more than two or three corners of the bolt. They are sized by metric millimeters.

Nuts and bolts have a six-sided shape which is usually spoken of as a hexagon. Stripping of the sides will occur if you do not use a tightly fitting wrench. The length of each wrench is related to the amount of force needed to tighten each size nut, so the force needed on your part should be the pull of three fingers. If the amount of effort required to tighten a nut or bolt increases, stop immediately as either you will break something or you are pulling the thread out.

Common uses of these wrenches are a size 15 open-end for pedals or a size 15 box-end for axel bolts (instead of a quick release skewer) to remove tires (commonly on fixed gear or mountain bikes). Sizes 8 and 10 are also the most common for various bolts and nuts on the bicycle.