t e ch suppor t rider’s seat should actually be placed in space in relation to the bottom bracket). Stack and reach virtually eliminate this confusion by simply showing how the frame actually fits. Stack and reach is a significantly improved standard from the traditional sizing methods that are based on effective seat tube length and other outdated frame dimensions, which are now virtually irrelevant when it comes to how the bike actually fits. Stack and reach is not without challenges, though, and it is important that you understand what the dimensions do not provide. Frame stack and reach dimensions do not take into account handlebar shape or stem length/angle and spacers. The size of the cycle-based stack and reach template we use in our fittings can take this into account, and there are other systems available that do as well. Regardless, you must know on which handlebar your stack and reach coordinates were based, and how those dimensions relate to the dimensions on the handlebar that either comes with the bike or that you will be using, as these can vary significantly and directly affect fit. Stack and reach does not include headset type. There can be up to 3 cm of effective stack difference between internal and external
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headset frames. If you are considering a frame with an external bearing headset (some custom and specialty brands), make sure to add in the headset you will be using to the listed stack dimensions. Stack and reach does not consider potential seat angle limitations on the frame. For example, if you ride a 75-degree seat angle and are considering a frame based on a 73-degree seat tube angle, make sure that there are seat post options for the frame that will allow the seat to be set to 75 degrees. This can be a problem, especially with frames that use integrated seatmasts or a proprietary seat post design. Even if the stack and reach dimensions look fine on paper, you need to be sure that any frame you are considering offers a configuration that will allow your saddle to be set to your riding position.
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Stack and reach is a step in the right direction and a notable improvement over the systems the bike industry has traditionally used. However, the best sizing representation I have seen comes from a manufacturer. On its E-114 TT/Tri bike, Argon 18 shows the factory-recommended set-up ranges for key positioning items, such as saddle height, setback, handlebar drop and reach, for each size. I hope that Argon 18 considers making this sizing
recommendation method more visible on its site and expanding it to include all their models (road and tri). I also hope other manufacturers adopt a similar system as the bike industry could make manufacturer-recommended sizing ranges much more clear to consumers and bike shops. Whether you are using stack and reach or some other frame sizing system, make sure you get a professional fit with a qualified fitter who also understands bike geometry before you settle on a bike. A rider-first fitting places the needs of the rider in front of the needs of the bike and guarantees that you will not be guessing when choosing what is likely your biggest equipment investment—your bike. Once you know your positioning coordinates, your fitter can help you narrow your options to include only those bikes that have stack and reach and that are appropriate to your needs before exploring other important variables such as handling, ride quality, cost and durability to find the best match for you. Ian Buchanan is co-owner of Fit Werx with locations in Waitsfield, Vt., and Peabody, Mass., and offers cycling and triathlon products, specialty bicycle fitting and analysis services, consultation and technology research. Visit Fitwerx.com.
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