Park Tool DH-1 Dummy Hub

The Park DH-1 Dummy Hub makes cleaning and transporting bikes much easier. It's designed to keep your chain under tension to enable pedalling forwards or backwards and to allow rear derailleur movement with the rear wheel removed. This is useful for a number of reasons.

When cleaning a bike on a stand it's much easier to remove the rear wheel first. You can get to the brake arch to scrub out and inspect the pads – impossible with the wheel in place – and properly scrubbing the drivetrain down is harder and takes longer with the wheel on the bike. Also, access to the inside face of the rear derailleur is much easier with the wheel out of the way.

But removing the wheel drops the chain, making turning the cranks likely to damage the chainstay, and you'll also end up jamming the chain into the chainrings. Enter the dummy hub, also known as a sleeping hub.

Find your nearest dealer here

Buy this online here

This fits into the rear dropout just as a cassette block does, lifting the chain back into the line it would follow over the cassette. The chain can then run back and forth when you turn the cranks without it jamming due to lack of tension. Unlike other dummy hub designs that are fixed in place at the 'highest' gear position, the Park DH-1 allows the derailleur to shift through its full range – opening it up and letting you get in there with scrubbing brush/sponge/cloth.

You can also slide the black plastic wheel off the blue alloy spindle and onto a 12mm thru-axle, to do exactly the same thing; 12mm thru-axles are increasingly common on road bikes with disc brakes and cyclo-cross bikes, so it's a nice future-proof feature.

Also, if you are sending your bike someplace – be it in the boot of a car, or in a cardboard box or high-end soft bag or plastic crate for airline travel – you really should be using a Dummy Hub to help protect the rear mech and prevent the chain from flapping about.

Some bike cases require the removal of the rear derailleur and there's no other option, due to the tight fit. But if you can get the frame in without removing the mech, it means you won't risk cross-threading it while jetlagged in a dingy hotel room somewhere hilly. It's always a good idea to shift the mech all the way inboard, and this is where the DH-1 design is great – you can do so with the chain held taut. And it's only adding 80g to your luggage.

While you need the wheel and cassette on the bike when you're setting up the front or rear mech, if you're dealing with another issue around the derailleur hanger, crankset, front mech or suchlike, and it's easier if you remove the wheel, the DH-1 will be handy for keeping the chain taut and pedalable.

Also, if you're a stickler for keeping your drivetrain as clean as possible, lubing the chain and leaving it set up on the DH-1 as opposed to the cassette will keep things a bit cleaner.

It's a simple idea beautifully executed by Park. It's compatible with most current road bikes and many future ones using the 142x12mm standard thru-axle. And it's small enough and light enough to fit in a toolbox or case for a trip.

No, it's probably not at the 'essential' end of the Bike Tool To Buy Next scale, but when you get one you'll wonder why you waited so long.

Verdict

Makes cleaning and transporting bikes much easier, by allowing shifting and pedalling with the back wheel off