SILENT, INSTANT - New BOX Stealth Hubs 20

Zzzzz, whoosh, brrrrrapppp, swoosh! That is your audible on-trail experience with the new BOX Stealth mountain bike hubs. The instantly engaging rear hub is completely silent, leaving nothing but swooshes and whooshes so you can have booshes on the trail.

The silent, instantly engaging hub is nothing new. True Precision Components (TPC) made this Stealth hub in California from 2006 to 2017, earning two Olympic BMX race medals in the process. In 2017, BOX purchased the Stealth hub platform from TPC because of the durability, simplicity, performance, and the potential it had for both BMX and mountain bike applications. BOX refined the design and the manufacturing process, took that to Taiwan and brought the costs down by 20%. Over the next two years, they tested the updated production versions, and today they’ve made the new Stealth hub official to the public.

At $349 for the rear Box Stealth hub and $149 for the front, mountain bikers have the option between 28 and 32 holes in Boost axle widths only. For now, XD and HG drivers are available with a Micro Spline option landing early 2021.

The tech nitty-gritty is refreshingly simple. The Stealth hubs use a precision, German-made one-way roller bearing to create engagement. They are designed for long life, requiring little maintenance, with minimal drag while being completely silent.

Because of the steel clutch race, as well as the durable, hardened steel freehub body, they are on the heavier side. At 475g for the rear the Box Stealth is on par with an Onyx but about 125 grams heavier than something like a Chris King ISO (which is also $100 more). BOX is working on a hybrid freehub body and a lighter clutch race that could drop hub weight by 90-120 grams - they’re aiming for spring of 2021 for that evolution.

Common-size, large-diameter Enduro-brand ABEC 5 LLU bearings are used throughout the hubs to ensure that replacement bearings and bearing presses are readily available when servicing is required. The flanges are angled for strength, and the hubs in are dressed in black-tie only with an alternating matte and gloss finish. They feature BOX’s limited lifetime warranty.

So, how do they feel on the trail? The silence speaks for itself, but after every ride, even though we thought our bike was pretty darn quiet, we found ourselves chasing every little rattle and noise on our YT Jeffsy 29 Base test bike. From cable rattle to levers jiggling to knobs coming loose, we damped it all. The bike is now covered in foam and electrical tape to keep it as quiet as possible so we can enjoy the silence of the hubs.

The instant engagement means there are no gaps in power when stomping on the gas or shifting. In technical climbing situations, where crank arm position and pedal-stroke timing is critical, the BOX hubs are precise and have been dependable. Need a little back-pedal to avoid that rock on the way up? No worries, the power will be there and pedals will be in prime position. On the way down, there’s nothing but a drag-free coasting experience.

Alright, we know, the big question, how does it compare to an Onyx, the other instantly engaging, silent hub we’ve grown to love? We can’t speak to long-term durability of the BOX Stealth hubs just yet, but so far they’ve handled some rough days at the bike park, in addition to a variety of XC laps in our local hills. The Onyx hubs, because of their sprag clutch design, have a bit of what we call sponginess with initial pedal stroke. It’s minimal and something we never minded. The BOX hubs, however, do not have that feel. When pressure is applied to the pedals, the feeling is robust and snappy, clearly different to the Onyx. The BOX rear hub is about $100 less, too.

As with any high-engaging hub, there can be increased pedal kickback on the trail depending on suspension design of the bike. This has been discussed deeply in our forum (and we’ve tested that Ochain thing that removes pedal kickback) - the long and short of it is that without any delay in engagement, suspension movement can be more quickly transmitted to the feet when using the BOX hub. We’ve never found this detrimental on trail rides or a reason to avoid hubs like this. The instantaneous power transmission is worth any minor tug we may feel from time to time. On longer-travel bikes it could become a more noticeable issue, but for applications where we care about motoring on the pedals through undulating trails, we believe quick hub engagement is a priority and a noteworthy upgrade to any bike suffering from a sloppy rear hub.

We see nothing but promise out of the BOX Stealth hubs. The price-to-performance benefit is strong, the simplicity of the system is a highlight, and the promise of even lower weight has us frothing for the future. The silence? Well, that’s golden. Any rider looking for a performance-boosting hub upgrade now has a great, new option with BOX Stealth hubs.

Visit www.boxcomponents.com for info or to purchase these new pieces of silent bling.

View key specs, compare products, and rate the Box Stealth hubs in the Vital MTB Product Guide.