Descend Integral Headset

Integral — IS in the S.H.I.S. naming — means the bearings drop straight into the head tube and seat on an angle machined into the frame itself, with no cup pressed in. Look into your head tube: a smooth chamfered seat and no cup means an integral frame. The giveaway on the spec sheet is stack height, which is 0mm at both ends here because nothing sits proud of the frame. Frames that need a pressed-in cup take the Descend Upper and Descend Lower instead.

The number before the slash is the bearing seat diameter at the top of your head tube, and 41mm and 42mm are indistinguishable by eye — a single millimetre is not something to judge by looking. Measure the bore, or take the figure from your frame manufacturer's own specification, before ordering. The lower half is IS52/40 in both versions, so the top is the only decision you have to make here.

A complete headset: the headset cap, the crown race, and both the top and bottom bearings. That is everything needed to replace a worn integral headset in one purchase, rather than sourcing a crown race separately afterwards. Spacers are not included — the Descend Headset Spacer Kit covers those if you want to set your bar height at the same time.

Less than most headsets. Because the bearings drop into the frame rather than being pressed into cups, nothing has to be pressed into the head tube at all. The one part that does need pressing is the crown race, which goes onto the fork steerer — a crown race setting tool does that cleanly, and any workshop will do it in minutes. Our headset installation and selection guide walks through the whole job.

Frame standard, not quality — all three use the same high strength steel angular contact cartridge bearings, running in bearing cups and crown races machined from AL6061. This one is for integral (IS) frames, where the bearing sits directly in the head tube. The Descend Upper and Descend Lower are for ZS (zero stack) and EC (external cup) frames, where a cup has to be pressed in, and they are sold as separate halves because the two ends of a tapered frame rarely take the same code. Our introduction to the S.H.I.S. explains how to read them.