Birzman Zyklop Voyager stem bag

Birzman Zyklop Voyager sounds like the stuff of cult 60's sci-fi but in fact it's a double decker stem bag designed so riders can safely use their smartphones, while keeping keys, credit cards and the like within easy reach.

There are two versions, one for the iPhone 4 or ours whose 128x70x10mm dimensions fit larger phones, GPS units, compact cameras or even OS maps.

Thirty quid buys a sturdy, water repellent PVC case with transparent top moulded to a glossy, carbon effect ABS base. Retro reflective piping running parallel to the zip is another welcome feature, subtle enough by day but blisteringly effective when combined with those proliferating clothes, tyre sidewalls, mudguards etc.

Peeling back the sensibly proportioned tags reveals a densely-padded Velcro bed cum trap door for docking one's delicate devices. The bottom bunk boasts similar refinement and a broad elasticated centre strap to prevent that irksome toolkit jingle. Efficient packers should manage small to moderate pocket tool, patch kit, tyre levers bank card/cash and micro pump. However, this sort of cargo requires a decent bracket and ours is already showing some signs of fatigue.

On the plus side, a choice of rubberised shims and lanky Velcro straps ensure dependable tenure to traditional and contemporary stem diameters without fouling extension brackets and similar accessories. Accessing the other compartment is faff-free with no fear of electronic gizmos falling to their death.

Unfortunately, the window prevented use of my phones touch screen, and the bag's water resistance is only adequate, as opposed to outstanding. It keeps out light to light to moderate rain, but a heavier downpour saw the interior wet within 15 minutes. That meant using the rain cover, which hides the screen, making the whole exercise a bit pointless.

Verdict

Some nice features but let down by lack of waterproofing.