We recently received our first shipment of 110 mm-long Grand Bois stems. The fillet-brazed stems are available in 10 mm increments from 60 to 110 mm. Now riders of all sizes can use these beautifully crafted, super-strong stems and decaleurs.
Some people may wonder about the shorter stems: Few modern bike makers specify stems shorter than 80 mm. However, for a small bike, it makes sense to shorten the stem, especially if you plan to use a handlebar bag.
In the drawings above, you can see how a 7 cm stem on a 49 cm frame places the handlebars in the same position as a 10 cm stem on a 58 cm frame, relative to the fork crown and front wheel. Therefore, a handlebar bag will sit on the rack in the same position.
No matter how tall your frame, your front rack always sits in the same place ahead of the fork crown. On the small frame, a long stem would push the bag too far forward, which would compromise the bike’s handling.
Beyond handlebar bags, there are other reasons to vary stem length over a greater range. Using a long stem on a small bike shifts the rider’s weight forward. To avoid toe overlap, many small frames have steep seat tube angles, which further reduces the weight on the rear wheel. This means that many small bike have much more weight on the front wheel than larger bikes typically do, and that probably affects the bike’s handling. A better way to avoid toe overlap is to shorten the stem and lengthen the top tube. The seat tube angle can remain almost the same as on a taller frame.
However, the stem length also affects the bike’s steering. A shorter stem changes the arc through which the handlebars swing. The effect is most pronounced “on the tops” near the stem, where your reach is determined solely by the stem length. “On the hoods” and “in the drops,” your hands are further from the steering axis, and the impact of stem length is less pronounced.
As everything in bicycle design, stem length is determined by a number of considerations. Different builders and riders weigh these factors differently, and thus design their bikes differently. Grand Bois now offers stem lengths that should suit most cyclists.