Bicycle Chain Length Stretch

Chain wear is commonly referred to as chain stretch because the chain s pitch grows in length as it wears.

Bicycle chain length stretch.

An exploded view of a single chain. A brand new chain will measure 12 inches across 12 links so if you measure your chain and it is 12 1 16 inches across 12 links then it s time to replace it. Because the chain s overall length grows with wear chain wear is commonly called chain stretch even though the metal does not measurably stretch. Chain wear often called chain stretch.

In the attached picture of my bike in the big big gears is the derailleur too stretched out. The cc 4 accurately indicates when a chain has reached 5 and 75 wear the points at which most manufacturers suggest replacement. An old style bicycle chain has ten parts per link. The chain length must match the distance between crank and rear hub and the sizes of the front chain ring and rear sprocket.

Place the ruler s zero mark at the centre of a chain pin now count 12 complete links. Finally there is an easy way to measure your chain for stretch that can be accomplished with a metal ruler with imperial or metric markings. The chain may or may not bear on the front face of the teeth near the return run and pull lightly back on the sprocket. There were 114 outer plates 114 inner plates 114 rollers 114 link pins and 114 bushings.

A bicycle chain is a roller chain that transfers power from the pedals to the drive wheel of a bicycle. The cc 3 2 is long accurate and features permanent measurement markings. The typical 57 link chain used on the average multi speed bike had 570 parts more than the whole rest of the bicycle put together. I installed new double chainrings that are 2 teeth larger but have not lengthened the chain.

This is the most important type of chain wear and the growth comes from the. On a new chain the 12 ruler mark should line up precisely with the centre of the chain rivet at this point. The american chain association manual 1972 edition includes the image below showing engagement of a new and worn chain with a new sprocket. It pedals fine in the bike stand but i ve not ridden it yet.

The park tool cc 3 2 is a go no go gauge designed to accurately indicate when a chain reaches 0 5 and 0 75 wear or stretch the points at which most chain manufacturers suggest replacement. The worn chain at the right is shown with links of unequal length.