Hi folks,

This is a follow up from one of my previous threads. I need some advice regarding stem length.

The frame I have is 21.5 inch, the seat post is protruding about 6.5 inch so the distance from bottom bracket to the top of the seat post is around 700 mm. What size stem should I use with this for the most comfortable ride? Is there a formula?

Thanks for any advice.

a good place to start is here

https://www.sheldonbrown.com/frame-sizing.html

It is going to depend on the length of the tope tube and the head tube, as well as the head tube and seat tube angles. It also depends a lot on individual preference.

Back in the dark ages when I started riding, the rule was to place your elbow against the nose of the saddle and your fingertips should reach the bar. I find on a couple of my bikes the bar is about 1" away and 2" away on another bike. They all feel fine to me.

Even though there are several different formulas for saddle height, they give very similar answers for most people, so you can consider it pretty cut and dried. For stem and top tube length it's much more of a judgement call. Sheldons site gives some background and some additional links, but no concrete answers. What most people do is either take the bike as it is and see if it's good, and if not either get fitted or start experimenting.

If you are getting a new bike the fitting should be done by the shop that sells it to you, and we can hope they have someone with a practiced eye. Ultimately it involves judgement, not math.

Same really with saddles, but math can get you to an acceptable starting point.


Road Fan

Another old school way of doing it was to look down while your in the drops....the bar should cover your front hub. Again, its an old school rule of thumb way of doing it.