SHIMANO XT DYNAMO DH UR705 3D 6V 3W CENTERLOCK BLACK FRONT HUB

Design and construction

A dynamo hub such as the Alfine DH-S501 is a generator: magnets in the shell spin around a coil on the axle and produce alternating current that a light or charger turns into something useful. The Alfine dynamo puts out the standard 6 volts and 3 watts, reaches useful headlight brightness at walking pace, and uses Shimano's low-drag design so it is hard to feel with the light off. The bearings are cup-and-cone, adjustable and rebuildable, and the rotor mounts by centerlock. Output is through a standard two-pin connector. The XT DH-UR705 is Shimano's lighter, lower-drag dynamo with the same output.

Because the front XT dynamo has no freehub, it is the hub that asks for the least: a spin of the axle to check the bearings once a season and nothing else. The flanges, bearings and seals are the same as the rear's, the axle converts between the front standards with end caps, and the rotor mounts the same way. Choose it to match a rear of the same model, or on its own for a fork that needs a new front wheel.

How it rides

An XT DH-UR705 wheel is close to a SON in drag and weight at a lower price, and it gives a gravel or touring bike a light that is always on and a USB port that does not depend on batteries. The XT dynamo is the Shimano dynamo we recommend for thru-axle forks; for a quick-release fork the Alfine DH-S501 is the choice.

On the road or the trail the front hub's job is to disappear: spin freely, keep water out, and hold the flanges still so the wheel tracks where you point it. The front XT dynamo does that with the same bearings and seals as the rear and none of the rear's complexity, and because a front wheel carries less load and no torque it stays true longer than the rear on the same rim. When the rear finally needs a look, the front usually does not.

Specifications

This version

This version is the centerlock hub in Thru Axle 12x100mm, drilled for 32h, about 450g, in black. Those are the only things that differ between the versions of the XT dynamo; the shell, bearings and seals are the same.

Centerlock is the lighter, quicker rotor mount: a splined rotor drops onto the hub and a single lockring holds it, so a rotor swap takes a minute with a lockring tool and there are no six small bolts to torque or lose. Shimano and most current road and gravel rotors are centerlock; 6-bolt rotors fit with an adapter.

Sizes, fit and compatibility

The Shimano XT Dynamo DH UR705 3D 6V 3W Centerlock Black Front Hub comes in the drillings listed on this page in 15 x 100mm thru-axle spacing with a centerlock rotor mount. J-bend spokes in any gauge; we build most XT dynamo wheels with DT Competition or Sapim Race and D-Light spokes and brass nipples.

It pairs naturally with the HED Belgium G, DT Swiss GR 531, Velocity Blunt SS and Cliffhanger, Astral Wanderlust and the gravel rims in the catalog. Pick gravel, commuter or touring as your bike type in the configurator and it recommends a spoke count and lacing pattern.

Put it in a custom wheel

Build a custom wheel around the Shimano XT Dynamo DH Ur705 3D 6V 3W Centerlock Black Front Hub — the link drops you into our Custom Wheel Program with this hub pinned, ready for you to choose the rest. It is set up for road rim brake, gravel and road disc, touring, tandem and e-bike, mountain bike, MTB single-speed and fat bike builds.

Building it at ProWheelBuilder

Shimano makes the XT dynamo; ProWheelBuilder is an independent custom wheel builder in Georgia and not the manufacturer. Spokes are cut from the ERD we measure on the actual rim, the wheel comes up in stages on a tensiometer, and it is stress-relieved and trued before it goes in the box; tape and a valve go on if you ask.

The configurator filters to what fits, crosses out what is not made, and prices the build as you go.