When assessing and treating runners with aches and pains, a factor that we often assess is the individual’s step width. A narrow step width, one where the feet land in front of each other instead of to the side is a leading cause of hip and knee pain due to the torque forces created by the directional force of a narrow stance. For runners this step width is self-selected so is often habitual or due to tightness in musculature. But in a sport such as cycling you are “locked-in” to your width which is dependent on your bike set up. This makes it particularly important to ensure that the width provided by the set up of your bike is suitable for your anatomy.

A correct stance width on your bicycle allows for efficient delivery of power and injury prevention. The tell-tale sign of incorrect bike stance width is when one or both knees flare out to the side at the top of the stroke. This mustn’t be confused with an issue of incorrect seat height which would cause this flaring also.

To solve the “knees-out” issue when it’s created by incorrect stance width there are a few solutions: 
1. Longer Pedal Spindle 
– different brands of pedals have different set widths of their spindles. Shimano also offer a 4mm extension to their 51mm spindle width- it’s not a large play but is ample adjustment to create a large difference for some riders.
2. Cleat Position 
– most cycling cleats have room to shift the cleat toward the mid-line of the body which allows for a wider stance width. This is often the easiest and most cost-effective adjustment.
3. Pedal Spacer Washers 
– if you need just that tiny bit more width then a 1.5mm pedal spacer washer then this is a great option. We don’t recommend using more than one spacer as there needs to be ample thread of the pedal into the crank.  
4. Pedal Extenders  
– if the first three options are not ample enough then a 20mm pedal extender might be just what you need. They weigh in at 37 grams and are worth the extra “bulk” to achieve optimal stance width.  

There are a multitude of factors that need to be considered for a cyclist on their bike. Each factor also has influence on a range of other parameters, so a clear understanding of both local and global body mechanics is required. Head over to our cycling services page for further information on our Sports Lab bike fitting service.