The chief advantage of Look's Ergostem is that precise adjustments can be made to reach and bar height to achieve the perfect riding position.
We know several bike clubs using them for the sole purpose of establishing the correct riding position among their members, but deﬂection testing wasn’t good – in use it twists noticeably more than other stems.
Its best use would be as a way of ﬁnding that elusive riding position before being replaced with a stiffer, more normal stem, but it’s an expensive way of doing it.
The Ergostem's design changed recently to improve the security of the adjustable sections, though the 6mm Allen bolts still require ﬁrm tightening to keep it from slipping. It’s only available in the 31.6mm oversized bar clamp diameter.