Stem Length and Frame Size
We recently received some questions about length of the stems from our customers. So we came up with a short article about this topic.
As we know, few modern bike designers specify stems shorter than 80mm. But it actually does make sense to shorten the stem for a small size bike, especially if you are a handlebar bag lover.
In the drawing below, you can see how a 70mm stem on a 49cm frame places the handlebars in the same position as a 80mm stem on a 56cm frame. No matter how tall your frame is, your front rack always sits in the same position ahead of the fork crown. If you use a long stem on a small size frame, it will push the handlebar too far forward, which would compromise the bikes’s handling.
Apart from that, using a long ste on a small bike will shift the rider’s weight forward. Some of the factories or bike makers will avoid toe overlap by steeping seat tube angles when they make smaill frames, which further reduces the weight on the rear wheel. This means that many small bikes have much more weight on the front wheel than larger bikes typically do. A better way to avoid toe overlap is to shorten the stem and lengthen the top tube. The seat tube angle remains the same.
However, stem length is determined by a number of considerations and different builders and riders weigh these factors differently.