Bicycle Chain Length Stretch

The worn chain at the right is shown with links of unequal length.

Bicycle chain length stretch.

Over time distance and cycling conditions the rivets and rollers begin to wear out causing the chain to actually stretch in length. This is the most important type of chain wear and the growth comes from the. Because the chain s overall length grows with wear chain wear is commonly called chain stretch even though the metal does not measurably stretch. 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.

Chain wear is commonly referred to as chain stretch because the chain s pitch grows in length as it wears. Place the ruler s zero mark at the centre of a chain pin now count 12 complete links. 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. The american chain association manual 1972 edition includes the image below showing engagement of a new and worn chain with a new sprocket.

On a new chain the 12 ruler mark should line up precisely with the centre of the chain rivet at this point. It pedals fine in the bike stand but i ve not ridden it yet. An exploded view of a single chain. The cc 4 accurately indicates when a chain has reached 5 and 75 wear the points at which most manufacturers suggest replacement.

The cc 3 2 is long accurate and features permanent measurement markings. I installed new double chainrings that are 2 teeth larger but have not lengthened the chain. 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. Bicycle mechanics derailleur stretch chain length.

An old style bicycle chain has ten parts per link. 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. In the attached picture of my bike in the big big gears is the derailleur too stretched out. There were 114 outer plates 114 inner plates 114 rollers 114 link pins and 114 bushings.

Chain wear often called chain stretch. A bicycle chain is a roller chain that transfers power from the pedals to the drive wheel of a bicycle.