Hello all, non-bike-expert here apologies in advance. I was wondering if I could get some advice... have got hold of a BMC Teammachine SLR03 and want to change the stem to something shorter - currently it's got a 120mm BMC one. Is there a standard size fit for stems or is there only a certain type that I can replace it with? Don't want to spend much if i don't need to. Also, would there be a recommended minimum length of stem or does that not matter so much? Attached a picture of it. Thank you, MFar