This frame bag by the textile manufacturers Buggy Bags, is custom-made to fit the bike. Originally, the company produced bags and equipment for kite buggies, but to meet demand for bike frame bags in the UK, they have since expanded their range. One of the good things about a small company is the personal customer service, and Jon and Helen are great.
The bag is made of tough cordura fabric, with several colours available and includes a main compartment. Extra features can be added, such as a map pocket, although this may depend on the size of the frame/bag. The zip is strong and is protected by a velcro flap that covers it. The bag attaches to the frame by wrap-around velcro and is very secure. If you want a custom logo or name added, this can be embroidered on. Basically, whatever you want, it can be done. And that is the great thing.
All you have to do is send in a template of your frame with the dimensions. It’s much easier than it sounds and there are detailed instructions on their website with photographs to follow.
My MTB frame is very small, and I did wonder if it would add much storage space. But I have been pleasantly surprised. It fits all the bike repair stuff I would take on any outing (pump, spare tube, repair kit, levers, multi-tool) as well as my cable lock and that leaves space too for enough snacks to see me through the day and I could squeeze in my phone and wallet if I needed to. Alternatively, it fits my Paramo waterproof jacket which doesn’t pack very small at all.
Of course, your bike frame may be much larger anyway, in which case you’ll have more storage space and options for additional pockets etc.
I think the bigger the frame, the more useful it is to have a frame bag. I would say my very small frame is on the lower limit of usefulness, but still tips in favour of having it. (It’s a 15″ Rockhopper)
My frame bag is perfect for a day trip in conjunction with my camelbak for water. Or it would be excellent with a seat pack and handlebar bag for extended trips of any number of days, which I haven’t had chance to do (although a 100mile Trans-Cambrian is coming up in September).
Essentially, it adds storage space where there is unused space and because it is in the frame, the weight of the gear you put inside is centrally located and so it doesn’t affect handling of the bike as if you had it on a rack or handlebar bag.
The one downside that I can see, is if you were mountain-biking/off-roading and need to carry your bike on your shoulder to get up any particularly steep hillsides, narrow paths, then you would probably need to detach it to carry the bike, because there is no easy hand-hold of the frame otherwise. But this is a rare event for me and probably most people anyway.
So, if you are looking for a frame bag, then a Bike-Bag would be a great choice. The quality is excellent, it’s custom-made and very affordable – one like mine is only £40 + p&p.