The Straight Cut Aon frame bag is a semi-custom bag, produced from start to finish in Scotland. As one of the brand's best bike frame bags , it combines web-style top tube fixing with a double strap for the downtube, creating an easy-to-mount design that is compatible with different bikes.

Straight Cut is a company that creates custom luggage designs but also has some off-the-shelf products available, including the Bagel Bar Bag and Top Tube Bag previously tested. The frame bag that has recently become available, in addition to custom bespoke frame bags, is what is usually known as a half-frame bag, as it will not take up the entire length of the top tube. The bag measures 31cm long, 15.5cm high and 6cm in width, which results in plenty of pedalling clearance.

Straight Cut offers the Aon frame bag with two fabric and colour options, with the version tested made from a combination of Cordura 1000d and X-Pac VX21 for the outer material. The areas touching the top tube and down tube are made using Cordura, chosen for its durability and resistance to wear. The attachment for the top tube is an elastic webbing cord, woven through slots in the top section of the bag. In terms of mounting, the first few attempts might take a little longer than velcro straps, but once you know the process it takes no time at all. One benefit of the corded attachment is markedly less frame wear (or frame rub) compared to regular velcro straps.

There is a strong, very water-repellent YKK zip that should stand up to the harshest of use, but it does make it harder to open or close, especially one-handed. The benefit of having a stronger zip can be crucial for bikepacking, where contents are often stuffed in and packed full, which can strain the zip. The bag features a 'zip garage' for when it is closed, although due to the size of the zip it can be tricky to fully push into place. One-handed use on the go is just about possible, but there are other bags that are much easier to open. Attachment for the downtube uses a twin velcro strap, with locking buckles to keep things closed and tight, plus small elastic tabs to keep the extra strap tidy.

The 2-litre capacity is ideal for carrying a lightweight inflatable mattress and various smaller items such as a tent pole, pegs, food and electrical items. To charge on the go, there is a cable port at the front to feed through from the bag, this is large enough to fit a hydration hose should you prefer to use it for water storage. The main pocket is on the right-hand side when viewed from the riding position and there is a slim pocket on the left, which would be useful for paper/card, or perhaps a map or other slim items.

I found the shape of the bag quite versatile and, despite riding small or medium-framed bikes, it managed to fit a road bike, gravel bike and mountain bike. Sure, it will leave limited space for accessing bottles - espcially on a smaller frame - but this is a known trade-off and not really a concern.

The bag is clearly well made, with perfect stitching and fabric to maximise performance and durability over weight saving. The Straight Cut Aon frame bag weighs 200g, which is by no means heavy, but there are other bags that are both larger and lighter. Apidura produces the Racing Frame Pack , offering double the internal space and weighing a claimed 195g but does cost a little more at £95. Another bag of similar style and shape is the Restrap Race , with the smallest version offering 3-litres of space, also weighing 195g for £80. There are some cheaper bags available in various styles including the Birzman Packman  at £37 but most of these options will come with some form of compromise.

The Straight Cut Aon frame bag doesn't bring anything truly new to the market but it's a great quality bag with a choice of fabrics that should make it very durable. The 2-litre capacity is not huge but I found it sufficient and ideal for smaller frames. With fully waterproof zips it will stand up to the worst of our British weather, although the exact zip model does make the pockets harder to open and shut compared to some rival options.

Matt is an endurance nut who loves big rides and big events. Former full time racer and 24hr event specialist but now happy riding off-road on gravel bikes or XC mountain bikes and exploring the mountains and hills of Mid Wales.

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