Xlab Frame Bags

Bolt-On vs. Strap Mounts: What Your Frame Actually Needs

Before you order, check your top tube. Bolt-on models like the Stealth Pocket 500 require standard mounting bosses - two threaded inserts spaced 64mm apart along the top tube, just behind the stem. Most modern triathlon-specific frames have these as standard, but many road bikes and older TT frames don't. Getting this wrong means the bag simply won't fit, so measure before you buy.

Strap-on models are far more forgiving. They use velcro straps that loop around the steerer tube and top tube, accommodating a wide range of diameters and shapes. The trade-off is a small amount of flex under heavy vibration - UK chip-seal roads in particular can get bags shifting laterally if the straps aren't tensioned properly. A non-slip rubberized base on XLab's strap models helps here, gripping the frame and reducing the micro-movement that causes wear over time. Still, on a bolt-on, that contact point is fixed. Cleaner, more predictable.

If you're running rear storage alongside your top tube bag, it's worth coordinating your setup - check out XLab saddle bags to see what pairs well with the frame bag range. And if liquid storage is part of your cockpit plan, the XLab hydration packs integrate neatly with the same mounting philosophy.

Stealth Pocket vs. Rocket Pocket: Picking the Right Model

XLab's frame bag range isn't a single product - it's a numbered hierarchy that takes a bit of decoding. The Stealth Pocket series runs from 100 through to 500, and the numbers don't simply mean bigger capacity. They reflect different mounting styles, finish options (including carbon-look panels on higher-spec variants), and subtle geometry tweaks. What stays consistent across the range is the 72-degree angled front face, designed to mate flush against a standard stem angle so there's no gap catching air between the bag and your cockpit.

The Stealth Pocket name comes directly from XLab's aerodynamic shaping - the bag's cross-section mimics an airfoil, narrowing as it trails away from the stem to reduce the turbulent wake behind it. It's a meaningful design choice, not a marketing label. Lower-number Stealth Pocket models suit riders who want a compact, lightweight option for shorter events; step up the range and you get stiffer side panels, better zip hardware, and the insulated silver interior lining that slows down gel and drink degradation on long-course racing days.

The Rocket Pocket series offers noticeably more internal volume - useful for full Ironman distances where you're carrying more nutrition and a spare tube or CO2. The extra bulk does mean a slightly larger frontal profile, so it's a conscious trade between capacity and drag reduction. For sprint and Olympic distance racing, the Stealth Pocket is almost always the sharper choice. The Rocket Pocket earns its place on long-course bikes where you simply need the space. Brands like Apidura and Lezyne offer competitive strap-on bento boxes, but neither matches XLab's depth of bolt-on triathlon-specific options. If you want a more adventure-oriented alternative, Ortlieb frame bags take a different approach entirely - sealed and fully waterproof, but with none of the aero shaping.

The Super-Slide zippers deserve a specific mention. They're designed to open with a single finger while you're tucked low - no pinching, no looking down, no breaking position. That's a small thing that becomes a very big thing at race pace. Miss Grape makes some well-regarded bento alternatives, but XLab's zipper system is purpose-built for the aero tuck in a way that general-purpose frame bags aren't.

Worth pairing your frame bag with a compatible XLab computer mount if you're building out a full cockpit - the two are designed to work together without conflicting for stem space.

Keeping Your Frame and Zippers in Good Shape on UK Roads

British roads do a specific kind of damage to frame bags. Grit thrown up by wet chip-seal gets under velcro straps and works like fine sandpaper against your top tube - particularly damaging on carbon. If you're fitting a strap-on XLab bag, apply a strip of 3M helicopter tape to the contact points on the frame first. It's invisible once the bag is fitted, costs next to nothing, and saves you a conversation with a spray painter. Clean the frame surface thoroughly before applying it - any grit trapped underneath the tape makes things worse, not better.

For bolt-on models, the main contact risk is at the boss mounts themselves. Use the correct bolt torque (check XLab's spec for the model you're fitting - overtightening on carbon is a real issue) and consider a small frame protector patch where the bag's base sits against the tube.

Zipper care is worth taking seriously. The Super-Slide zippers hold up well, but sweat and sports drink spillage are corrosive over time, and grit from road spray accelerates wear. Every few weeks, run a toothbrush along the zip teeth to clear debris, then apply a dry silicone lubricant - not WD-40, which attracts more dirt. A seized zip on race morning is a problem that's entirely avoidable with ten minutes of maintenance across a season.

The insulated silver interior lining also benefits from a rinse after long events. Gel residue left to dry in there becomes sticky and eventually degrades the lining's reflective coating. Warm water and a quick shake-out is enough - no need for anything stronger.