PULSTAR SUSPENSION FRONT HUB
Pulstar makes a Suspension front hub to satisfy the interests of over enthusiastic Mountain bike riders. The Suspension front hub uses an oversized axle within the same CNC machined billet hub shell. The hole drilled through the hub and the bores performed from each end are done in a larger diameter. The bores are 30mm in diameter and the through holes is 22.5mm. To accommodate the larger hole and larger a larger sealed bearing is used, in this case its the Japanese WTW 6903RS. The aluminum tube for this version of the Pulstar front passes all the way through the hub. It has a 17mm outer diameter and a 9.1mm inner diameter. The axle for this hub is machined from 6061-T6 aluminum rod. It has a 9mm outer diameter and slides through the thicker aluminum tube. The description now gets slightly more complicated. The Suspension hub comes with a quick release skewer, only it's incorporated into the axle. The axle has interior threads on one end, and has a permanently fixed "nut" at the other. The axle with the nut passes through from one side of the hub and a short length, (16mm long) steel skewer threads into the axle's inner threads from the other. A lever actuates a cam which constricts the axle/skewer locking the front wheel to the bike. A machined aluminum cap at each end of the axle has a fastened serrated face steel washer. This 22mm diameter steel face is what makes contact with the inner fork end. We found the hub actually revolving on the larger aluminum outer axle, until weight was placed on it, when the revolving bottom of the larger aluminum rather pushed against the bearing making it finally turn. This is because the larger aluminum axle is slightly under sized and revolves freely when bearing no weight. If it were made large enough that it required pressing through the bearings it would use them more effectively. As it is, the aluminum to steel contact is un-lubricated leading to premature eradication of the aluminum axle. Some re-engineering is in order. Changing the outer axle or the end caps would make the difference. The Pulstar Suspension front has a 53.7mm hub flange diameter, with the flanges spaced 70mm apart. The Pulstar standard front spoke holes have a 47mm center circle diameter. It is available in either a 28 or 32 spoke hole drilling. The hub shell comes anodized in Blue, Black, Grey, Lavender, Silver. The inner axle, caps, nut and lever are anodized Black. The weight of a 32 hole Pulstar Suspension front with lever is 232 grams.
