Soon To Be Racing

[Mr Haematocrit]

I'm with Rob3rt on this one, I went from a 110 to a 90 and can notice the difference noticeable is in fit and comfort. Handling feels no different

 

[Rob3rt]

I'd have to disagree on this one through my own experiences, especially when it comes down to sprinting - short stems seem far twitchier! I also had a 130mm stem on my cyclocross bike, now that it is 110mm I can feel a huge difference in handling on and off road, but that is just me

Stems in the "normal" ranges ~80-120mm, the handling difference is essentially not noticeable if you make smallish changes i.e. 10-20mm IME. Once you start putting silly <80mm stems or 130mm+ stem's on or jumping 40mm in length in one go, I agree with your observations, you start to get a twitchy or sluggish feeling to the bikes handling depending on which way you go (relatively speaking). With regards to OP, unless the stem supplied on the 50 cm frame was right on the limit of "normal", a +/- 20 mm stem would be unlikely to produce a significant steering difference IMO. Especially not to the degree is aids someone transition to riding road bikes.

This is just my experience though, like you said, you have a different experience.

 

[black'n'yellow]

You need to think of stem increases in percentage terms. For instance, going up 20mm from 60mm to 80mm represents a 33% increase in length, while adding the same 20mm to a 100mm-120mm stem will only give you a 20% increase.

Either way, a longer stem will inevitably 'slow' the handling a bit. Whether that is a good or a bad thing depends on what the handling was like before and what it will be like after.

 

[montage]

Stems in the "normal" ranges ~80-120mm, the handling difference is essentially not noticeable if you make smallish changes i.e. 10-20mm IME. Once you start putting silly <80mm stems or 130mm+ stem's on or jumping 40mm in length in one go, I agree with your observations, you start to get a twitchy or sluggish feeling to the bikes handling depending on which way you go (relatively speaking). With regards to OP, unless the stem supplied on the 50 cm frame was right on the limit of "normal", a +/- 20 mm stem would be unlikely to produce a significant steering difference IMO. Especially not to the degree is aids someone transition to riding road bikes.

This is just my experience though, like you said, you have a different experience.

Thinking about it...I've recently changed from 110mm to 100mm, or the other way round, I've forgotten. Definitely not noticed any difference in handling there. On the other extremes I've raced with a 60mm (borrowed bike) and a 130mm stem and they did make a difference

 

[Monsieur Remings]

I've changed the stem from 100mm originally to 110mm and have experimented with taking spacers out and with each length stem to find the best fit all round.

IMO, it does make a difference indirectly to handling, namely descending. Having got used to a 110mm stem which I found a touch too long on the open road but better descending in aero-tuck position, I found consequently that the 100mm felt too cramped in the aero-tuck, changing my position on the saddle and the way I leant forward, my hands on the bars and no doubt my C of G. This is only a marginal difference but it is very noticeable.

As B and Y mentions a 20mm difference is quite a significant difference.