The Bike List

What are Stack and Reach measurements and why are they important?

Stack and Reach measurements describe how a bike will feel to sit on. The measurements are independent of the bike's setup such as saddle setback, seat post length, stem length etc and are directly comparable from one frame to another.

Stack and reach measurements have become increasingly important as frames sizes have stopped reflecting the length of the seat tube and continued to vary greatly from one manufacturer to another.

Frames that have very similar stack and reach measurement can vary up to as much as four traditional (54,56,58,60 cm etc) sizes apart. What one manufacturer calls a 56cm frame, could easily be equivalent to a 54cm or even a 58cm frame from another and may not even be a true 56cm frame in the first place. This means that you can't simply transfer your frame size across from one manufacturer to another and expect a great fitting bike.

How do stack and reach affect how a bike feels to ride?

As the stack number gets bigger, the seated position becomes more relaxed and upright (if reach stays the same). A larger stack measurement relative to reach is common on bikes that are designed to be comfortable for long periods of time.

As reach grows, the seated position becomes more stretched and aggressive / aerodynamic (if stack stays the same). A larger reach measurement relative to stack is common on bikes that are designed to be fast such as racing bikes.

Fortunately stack and reach measurements are all taken from the same place on a frame making comparing frames using these measurements very straight forward.

Where are Stack and Reach measured from and to?

Stack is the vertical measurement from the centre of the bottom bracket to the top edge of the head tube.

Slightly confusingly 'reach' is not the reach from the saddle to the handlebar.

Reach is in fat the horizontal measurement from the centre of the bottom bracket to the top edge of the headtube.

The Bike List personalised frame recommendation - find the best fitting bike

Search our database of over 100 brands for free to help you find a great fitting frame. Simply enter your height and inside leg measurements and email address and we'll search our database of stack and reach measurements to recommend frames that will offer you a great fit. We'll then also email you that list as a PDF that you can download and take to your local shop and write notes on.

You may find that we have recommended frames that are two, three or even four sizes apart. Their stack and reach measurements will be very similar and will therefore offer a very similar fit when you sit on them. The thing to note here is that stem length, handlebar width and depth, crank length and the type of seat post (setback or straight) will all impact how a bike feels to sit on and two frames that have the same stack and reach can feel very different if all of those components are different sizes. If frames are one or two sizes apart then there's a higher chance that those bikes will have different length stems, handlebars, cranks etc. Our downloadable bike test guide helps you capture all of these differences. Don't forget you can also easily change a stem, handlebar or seatpost.

By entering your measurements on our frame size recommendation page, we can also determine if you have a long or short torso or legs relative to your height. This is important as the same size bike will feel different for people who may happen to be the same height but have different leg and torso lengths. For example, bikes that would feel aggressive for someone with an average torso and leg length would feel more relaxed for someone with shorter legs and a long torso as they would be able to reach the handlebars more easily, placing them in a slightly more upright position.

The advantages of a great fitting frame

It can sometimes be possible to make a bike that is too small or large fit you by adjusting the seat height, saddle setback, stem length etc. This is fine up to a point however if a bike isn't a great fit it can negatively affect how a bike handles. If your centre of gravity is not where it really ought to be then the bike won't respond how the manufacture intended. To add to that a poorly fitting bike will often not be very comfortable which will impact your biomechanical efficiency, comfort and probably also enjoyment. Riding for prolonged periods in an uncomfortable position can also lead to injury.

Fine tuning

Once you have tried a few bikes and found one or two that offer a great fit you are well on your way to buying a bike that you will enjoy riding.

A good bike shop will look at your physique on and off the bike and will make final adjustments to improve the fit and comfort further.

Age and therefore flexibility play a big role in what bikes you'll find comfortable. Generally as we get older we become less flexible, unless we stretch often, and this will influence what type of bike you'll naturally feel comfortable on.

For anyone new to cycling, particularly road cycling or where drop handlebars are used, your flexibility will most probably improve over time as you become used to the new riding position. Most bikes will allow for adjustment later down the line if flexibility improves to the point of wanting to adjust the height of the stem or position of the saddle etc.