Tubus Disco rear rack

The Tubus Disco is a rear pannier rack for a kind of bike that isn't designed to take one: a cyclocross, mountain or (these days) road bike with a disc brake caliper attached to the seat-stay and no rack eyelets at the dropouts. In a sense, it's a solution for the cyclist who bought the wrong bike. If you plan to use a rack, why not get a commuter, tourer or adventure road bike with rack eyelets and the disc caliper tucked out of the way on the chain-stay? But it's easy to be wise in hindsight, and this sturdy German rack lets you carry luggage on a bike you didn't anticipate equipping with panniers.

It's made not from aluminium rod but chromoly steel tubes. That means it's stiff and strong for its weight. It's rated to carry 20kg, as much as many sturdier-looking aluminium racks. It's also why it costs £95. Steel is easier to weld if you do break it on the way to Timbuktu or wherever, although for the vast majority of owners that will be only a hypothetical advantage.

Like some other pannier racks designed for disc brakes, the Disco dog-legs back at the lower attachment points so that the rack struts don't foul the disc caliper. The bottom of the rack is wider apart than usual, and Tubus provide a pair of 5mm thick spacers to fit between rack and bike. This increases the clearance between the disc caliper and the pannier on that side.

If your bike has eyelets above the dropout, you can fix the rack to those, like you would a normal pannier rack. I tried this on the one bike I've got with disc brakes and rack eyelets, a Genesis Longitude. While the rack attached okay to those eyelets, the top of the rack then sat so high (6cm above a massive 29er tyre) that the adjustable 'horizontal' struts at the top of the rack wouldn't reach the seat-stay eyelets when the rack was level.

If your bike doesn't have eyelets at the dropouts, you'll need to use the wheel quick-release instead. This is the default option and it puts the rack at the right height on your bike. Tubus supply an extra-long quick release. You need to use this instead of your bike's existing quick release because the latter won't be long enough when you factor in the 5mm spacer washers. Tubus sternly warn you not squeeze the lower struts together by more than 15mm, as this will weaken the rack. You shouldn't need to do so. On a 135mm rear end, the Disco fits neatly around the rear hub (with the two spacers in between rack and bike). On a 130mm rear end, you'd only need to squeeze the rack together by about 5mm.

The top of the rack fits as normal to the eyelets at the top of the seat-stays, using strong, adjustable struts. If your bike doesn't have the upper set of eyelets, you'll need P-clips or a seat collar with integral rack eyelets.

When it's all properly fixed together, the Tubus Disco feels as secure, strong and stiff as a conventionally attached rack. Until you have to remove the rear wheel, you might forget that your wheel quick release is holding both rack and wheel in place.

The triangle formed by the rack's side struts is an acute one, so the Disco suits small or medium panniers better than enormous ones. I'd be inclined to use it for commuting or touring on good roads rather than bumpy dirt roads; I can't see it ending well when you've got bouncing panniers supported by a narrow-diameter quick release. For the rough-stuff touring you might be inclined to do on a cross bike or mountain bike, a big saddlebag like a Carradice Camper Longflap or a bikepacker's bag like a Revelate Viscacha would arguably be a better solution.

The Disco comes in two sizes: 26-inch and 28-inch wheels. The latter suits 700C. Both have a mounting point at the rear for a rear light.

Verdict

The best way to carry rear panniers on a bike with a seat-stay mounted disc brake and no rack eyelets