Whether you are a bike mechanic, a home mechanic, or just like to keep your bike looking pro then you’ve got a regular washing routine. While yes you can clean the drivetrain with the rear wheel mounted, the nagging issue is that the best way to get into the rear triangle or the rear derailleur is to remove the back wheel. But what to do about the chain then? That’s where ingenuity ensures that there is an answer to all of life’s little problems. Meet the dummy hub, sleeper hub, chain keeper, or wash hub. I’m pretty fond of my Park Tools DH-1, it’s a rad little helper.
what does it do?
Whatever you like to call it, the dummy hub replaces the rear wheel and cassette in the rear dropout to keep the chain under tension for cleaning and during transport. This helps ensure your chain isn’t slapping your rear chainstay scratching the paint or at worst chipping your carbon.
How do they work?
There are various designs but all are quite simple and work around the same premise. A small pulley wheel is mounted on a stainless steel axel. A quick release secures the dummy hub to the rear drop out and the pulley wheel slides along the axel inward and outward allowing you to shift through your gears for maintenance checks or to provide more room to access the inside of the rear derailleur.
I made this video to show my Park Tools DH-1 in action on the bike stand.
the park tools dh-1
The Park Tools DH-1 costs about $18USD either online or through your local bike shop. It weighs just 80grams (128gr with the shipping container) making it a really small but smart investment to put in your home workshop or travel kit. It works with any derailleur and 1/8” chains. It’s future proofed because the pulley wheel can be mounted to a through axel up to 12mm. The Park Tools DH-1 comes shipped in a small cardboard tube with an instruction pamphlet included.
I ordered mine through the parts desk at Urbane Cycle (ucycle.com) when it was first announced. Because it hadn’t been stocked at any Canadian distributors yet it took about a month to arrive. It’s now common stock which means shops may likely have them or can get them in about a week. Park Tools has a list of stockists on the product page here.