Why tapered steerer tube

The steerer will flex way before the lower legs will, and that will put too much stress on the head tube. Fork stanchions are, in some cases, similar to steerer tube in size but made from a stiffer material. When tapered steerers first appeared, the taper was pretty long. Luckily, RockShox solved this problem years ago; now, none of the fork brands make tapers longer than 63mm.

When a tapered steerer flexes, it does by a much smaller degree and equally spread through its length. The pressure applied is almost always one-directional. Meaning the lower and upper part of the headset are both pushed in the same direction by the steerer.

The flexing causes the upper headset to be pushed upward on straight steerers while the steerer moves the lower headset downward. That tends to loosen the headset often, which increases the likelihood of headset and head tube damage. This process is, even more, sped up by bearing wearing out much quicker. Putting pressure in two opposite directions is effectively doubling the pressure bearings are put through.

The thing is, it was a problem, just not big enough for everyone to notice. When riding became more technical and more aggressive during the years, head tubes started breaking more often. Otherwise, we would see head tubes break even more. Purely anecdotal but… a few years back I changed from a Top Fuel to a one. The one handled a lot better, just felt more like it went where you pointed it. Could just be that the Fox is a lot stiffer than the SID, or could be tapered steerer. The worst thing is when companies spec tapered forks with open dropouts.

My tapered steerer reba 29ers are noticeably less twangy under braking than fox 32 26er straight 1. I then picked up the 1. The 1. Summary — In my experience 1. Head tubes require cut outs where the top tube and down tube weld into them ditto for bottom bracket shells by the way.

The manufacturing procedure for carbon fiber is radically different —layers of carbon fiber sheeting are bound together in one mold to create a singular unit.

Note how the head tube is merely an extension of the frame; the head tube walls merge into the top tube and down tube. A head tube, tapered or not, is defined by the angle forming the steering axis which creates the trail allowing a bike to work. You can fit a straight fork to a tapered head tube with an adapter, a crown race reducer. Head tube tapering is now re-appearing in some frame designs, however, though more for aesthetic than functional reasons, as internal cable routing and the rapid uptake of ebikes dominates bike design and builds.

Your email address will not be published. In a tapered head tube, the lower diameter is wider than the upper. In the following sections I explore the original tapered head tube how the tapered head tube works, and the reasons for using one I also discuss how recent innovations in bike technology look like reducing the role of the tapered head tube in bike design where this type of head tube has, hitherto, dominated.

Emtb tapered head tube. Embedded from r2-bike. The length of that taper dictates the minimum length of the head tube, because the steerer has to fit through the smaller upper headset bearing. If the taper is too long—or the head tube too short—the upper headset assembly will jam on the steerer. A smooth taper is good, because it eliminates a squared off step down, which can create a stress riser.

But draw the taper out too much head tube needs to expand to accommodate the fork steerer. And long head tubes are bad news for XC racers who want a low bar height, shorter riders, 29er riders, and shorter riders who want a 29er.