NS Bikes Coaster DH 150 (12 mm) - 36 H

NS Bikes Coaster DH 150 – rear hub for downhill and freeride

A downhill rear hub is judged by what it survives on landing, not by its catalogue weight. The NS Bikes Coaster DH 150 is built around 150 mm spacing and a solid 12 mm nutted axle – the standard most previous-generation downhill frames were designed for. The shell is CNC-machined aluminium and the complete hub weighs 448 g. Four sealed cartridge bearings run inside. Oversized flanges and 36 spoke holes are there for one reason: so the wheel survives a bikepark weekend without needing a true afterwards.

150 × 12 mm spacing and a solid axle

A 12 mm axle passes through the whole hub and ties both dropouts into a single structure. On a quick-release setup that job falls to a thin 10 mm skewer that only pulls the dropouts together. On a downhill bike the difference shows up under hard braking into a corner – the rear wheel has nowhere to wander and holds the line the rider picked. The Coaster's axle is smooth, with threads and nuts at the ends. A regular wrench undoes it, no proprietary tool involved, and the nuts torque down harder than any quick-release lever manages. The 150 mm dropout spacing is the downhill standard from the 26" era; it cannot be swapped with today's 148 mm Boost or 157 mm Super Boost.

What does 150 × 12 actually mean?

The first number is the rear dropout spacing, or OLD (over-locknut dimension) – the distance in millimetres between the inner faces of the dropouts. The second is the axle diameter. The frame dictates both and neither can be fudged with washers: a narrower hub will not clamp square in the dropouts, a wider one will not fit between them. Measure the spacing with calipers before you buy, or look it up in the frame's geometry table.

Oversized flanges and 36 holes

The flange is the ring the spokes come out of. The larger its diameter, the steeper the angle each spoke makes with the plane of the wheel – and the harder it pulls against sideways movement of the rim. That is what the oversized flanges on the Coaster DH are for: a laterally stiffer wheel built from exactly the same spokes as a low-flange hub would use. The other half of the equation is the hole count. 36 spokes spread the load across more points than the usual 32, so each spoke carries less of it and the rim is slower to go out of true. For downhill and freeride that is not a luxury – a wheel that survives a bikepark day without a re-true saves more time than a few dozen grams ever will.

Four sealed cartridge bearings

A cartridge bearing is a closed unit with its own cage, balls and seals. There are no cones, so it cannot be set up wrong – it either spins or it gets swapped. Against a traditional cup-and-cone setup that means two practical things: the feel does not shift after the first heavy landing, and servicing is a matter of pressing the old one out and the new one in, instead of chasing preload with a pair of thin cone wrenches. The Coaster DH 150 runs four of them – two in the hub shell, two in the freehub body. The seals keep water and mud out, but nothing lasts forever. Once the rotation starts to feel gritty or play shows up at the rim, the bearing gets replaced; with a puller and a press any bike shop handles it.

Freehub and wheel build

The freehub body is Shimano HG, the most widely used standard there is. Shimano and SRAM cassettes with eight, nine or ten sprockets fit, as do Shimano's 11-speed MTB cassettes, which were designed for an HG body. What does not fit: SRAM XD/XDR and Shimano Microspline – those need their own freehub and no adapter gets around it. The rotor mounts with six bolts to the IS standard, so any common MTB rotor will do. Plan the wheel build around a 36-hole rim; hub and rim hole counts have to match. Spoke lengths are calculated from the dimensions of both parts – on a rear wheel the left and right sides come out different, because the room needed for the cassette pushes the flanges off centre.

Full technical parameters are listed in the Specification tab of this product.

Frequently asked questions (FAQ)

Does the Coaster DH 150 have a coaster brake?

No. "Coaster" is an NS Bikes model name, not a description of the mechanism. The hub has a conventional cassette freehub with a ratchet and is stopped by a 6-bolt disc rotor. A freecoaster – a hub that does not engage when pedalling backwards – sits in a different NS Bikes line and should not be confused with this model.

Which frames does the Coaster DH 150 fit?

Downhill rear ends with 150 mm dropout spacing and a 12 mm through axle. Most DH frames from the 26"-wheel generation use that combination. It will not go into a frame spaced at 135 mm, 142 mm, 148 mm (Boost) or 157 mm (Super Boost) – spacing cannot be adapted with spacers. If you are unsure, measure the distance between the inner faces of the dropouts.

Which cassette can I run on it?

Any cassette made for a Shimano HG freehub: 8-, 9- and 10-speed Shimano and SRAM cassettes, plus Shimano 11-speed MTB cassettes. SRAM XD or XDR and Shimano Microspline need their own freehub body and will not mount on this hub. With an 8- or 9-speed cassette you normally add a 1.85 mm spacer behind it.

Which rim should I pair it with?

The rim has to have the same hole count – 36. For downhill use pick a double-wall rim with an internal width of roughly 25–30 mm so it supports a 2.4" tyre and wider. Have the spoke lengths calculated for your specific hub and rim combination; there is no universal length.

Can the bearings be replaced at home?

Yes, these are standard sealed cartridge bearings. The old one is pulled out and the new one pressed in – without a press there is a real risk of seating it crooked and binding it. If you do not have the tools, it is routine work for any bike shop. There are no cones to adjust, so between replacements the hub needs nothing beyond keeping it clean.