djdelarosa25

More than six months ago, when my friend and I got our road bikes (Giant Contend 2), we swapped stems the moment we stepped out of the store. I gave my 80 mm stem to him as he felt too stretched out on his bike (I think it was too big for him) and he gave his 100 mm stem to me as I thought I could handle a slightly longer stem than what I was used to riding. More than six months later of tweaking my setup, I'm starting to think that just maybe the stem I have now is a bit long for me, or maybe I just have a weak core. I could hold a position where the front axle is behind the handlebars (this seems to be a rough guide to determine proper stem length), but over time, it does lead to hand numbness. My elbows have a slight bend to them when I'm on the hoods and I don't experience any pain in my arms. Moreover, I feel that when I'm fatigued, my spine tends to bend and my shoulders would project outwards to reach the drops. If I were to change my stem length, should I try one with the same length as the stock one (80 mm)? Is a 100 mm stem even considered excessive for my height of 164 cm, or is it average?

My bike is a size XS and the geometry chart can be found here. Thanks in advance.

Iride01 

I'm going through a similar thing. When I got my Tarmac, I had a frame that had a stack height that would finally let me get lower than my two bikes from days gone by. I very much like the lower handlebars. However I might actually would have been better fit on a smaller 54 cm frame. Wish I'd tried one. But since my previous two bikes were 59 and 60 cm and I have ridden a 25" bike for 35 plus years, and all comfortably. I couldn't believe then that a 54 cm would ever be right for me.

But short answer, yes you might want a shorter stem. I'm looking for one too. But the stems I want are all out of stock.

Might go down to a 70 mm stem from 100 mm.

headwind15

I am a short cyclist expert. A store owner for over 12 experience helping with sizing/ riding styles. With a 51.5 cm top tube the frame should be plenty short. This is likely about your riding style. With modern road bikes, a lot of (road) cyclists have adopted the style where they ride all of the time on their brake lever hoods. I have some cyclists who basically can't/ wont take their hands off the security of being within close range/ right on top of their brake hoods. I suggest that you spend a lot of time on the tops and switch your hand position to the hoods for shifting, braking and when getting off of the saddle (while climbing etc). I think you will find that you actually need a longer stem.

Carbonfiberboy 

Get on the bike, hands on hoods, forearms horizontal. If your torso/upper arm angle is about 90° it's perfect. Yes, many pros ride bikes which are too small by this measure, but they get paid to do that. This setup is the most comfortable over long distances. Actually you'll find that throughout the range of elbow bend, your upper arms will stay at ~90° to your torso. Your upper arms are supposed to be a simple strut, no muscular effort to hold that position.

philbob57

That 90 degree heuristic may work for people of average upper arm and forearm and total arm dimensions, but not for people who don't fit the model. Further, if someone does have average dimensions and a 90 degree angle and feels uncomfortable, should the person stay uncomfortable or ignore the 'rule'?

Core strength can be evaluated in at least one parameter pretty easily. How long can you hold a plank position? A minute or longer - maybe core strength is OK; much less than a minute, probably a weak core.

I thought the rule of thumb was having the bars obscure the front hub while on the hoods, but I ride an old bike with a ROT of bars obscuring the hub while on the drops. If your bars are in front of the hub, I think that's a longer reach than recommended. Also, I think 100 mm is longer than most manufacturers put of frames for people your height.

But I think numb hands say too much weight on your hands. IDK ... I use a quill stem, and changing stme length is a big deal for me. All you need to do is remove and replace 8 allen bolts to try out a shorter stem. Besides, it looks like you've used a shorter stem with success, so I'd recommend trying out a 70-80 mm stem.

Carbonfiberboy 

I didn't think I needed to mention it, but guess I do: The first thing one does is adjust saddle position, then stem. My bike fit primer is here: https://www.bikeforums.net/21296948-post3.html
That's simplified of course, but that's how it's done. Body proportions don't enter in to it. Following that path allows for all that, which is the reason fitters use it.

Numb hands usually means the saddle is too far forward or the person is riding with straight arms or doesn't change hand positions frequently. Or they don't understand how to position their hands on the bars: https://www.bikeforums.net/road-cycl...l#post12953035
Increasing reach by using a longer stem takes weight off the hands rather than increasing it, assuming that hip angle does not change.
The bars obscure hub thing is like KOPS: Works well for people of average proportions.