Ortlieb Frame-Pack RC Toptube

The Ortlieb Frame-Pack RC Toptube is great. It's truly waterproof, extremely well made and very secure. It's not cheap, but if you want a fit-and-forget bag that's as stylish as a fabric sausage can be, this is an excellent option.

As children we learn that the sum of the internal angles of a triangle is always 180 degrees, but as adults we learn a more fundamental truth: triangles are brilliant for storing processed cheese and/or spare jackets. As this 3L bag doesn't say Dairylea on it anywhere, today I'll be concentrating on jackets.

All that space in your front triangle usually only plays host to a bottle cage, and this bag leaves room for those with just 15cm of drop. In fact, its 4L brother only drops 13cm as it's 10cm longer; there's no need for a side-entry cage with either.

While the 50cm-long 4L version would fit my large (57cm) frame just fine, I prefer this smaller 40cm version for comfort reasons I'll get to in a minute. Note that Ortlieb offers downloadable templates should you want to check how these will work on your frame.

This 3L isn't close to filling the 52.5cm gap between my bike's seat tube and head tube, and that's no issue – the single straps front and rear are removable (they each have multiple mounting points, the better to suit any frame), so you're not left with Velcro flapping around if the bag doesn't reach both ends.

The mounts along the top can also be removed and/or repositioned, should you have cable guides or anything else to avoid.

While the size of your legs and the way you pedal will affect what rub you may suffer (if any), I tend to find even slim bags annoying – with the Ortlieb strapped against the seat tube I'd brush against the 6cm-wide rear section enough for it to be distracting. Moving it forward in the frame triangle and strapping it to the down tube instead improved that, and after some fine-tuning – moving the rearmost closure forwards and twisting its pull-tab so it no longer sticks out sideways – I completely cured it. At this point it became one of my favourite bags, and for me it only lacks one thing.

That thing is an external pocket, one big enough for a phone. I wouldn't even care if it was mesh (phones can wear their own protection), but a quick-access holder for my annoyingly needy/useful device would be the icing on the cake. Still, this bag is available with a zip instead, with the same impressive IP67 waterproof rating, so if you like your phone to hand that's perhaps the one to go for. It's quicker to undo. The zipped one has the same name as this, just without the 'RC' for rolltop closure.

Hang on, I never said this one was IP67 to start with. Whoops. It is! That means it's proven completely dust-tight (in a test of up to eight hours), and waterproof enough to sit in one metre of water for 30 minutes without leaking, much like an Oceangate submarine. In other words it's waterproof enough to resist even Welsh rain, and while the outside will darken and look soggy during a drenching, nothing will get through to the inside. I left it in the shed after hours of riding in rain and, the next day, all the textiles inside were bone dry.

It must be rolled three or four times to achieve this rating, but that's just the natural-feeling way to do it and there's a rigid strip on one side that makes it very easy to fold. The rubber loops are easy to hook shut, too, thanks to those pull tabs, though as I said, they do naturally jut out and will potentially catch on knees.

The only odd thing here is the strap arrangement for narrow tubes, which the instructions say is anything under a 40mm diameter. I tried it on my steel gravel bike (28mm) and frankly it was awful, leaving a large flap sticking out sideways. The instructions say to fold it, but there's no room to tuck it back and nothing to stop it unfolding. Eventually I switched back to the big-tube way of threading the three upper mounts, and everything worked perfectly. Strange.

Value

At £101 this is up there with the most expensive options, though it doesn't feel overpriced – the quality and performance are excellent.

You can spend a lot less, though you may find compromises. The 4.2L Zefal Z Adventure C4 Frame Bag is well made and only £48.99, for instance, but while it's very resistant (IPX4) it's not actually waterproof. It can also chafe pretty badly thanks to some poorly located edges.

The Lomo Bike Frame Dry Bag is cheaper still at just £26, and it's excellent for the price. You'll need a side-entry cage if you want to run a water bottle, however. Lomo doesn't give a capacity, but it's somewhere around 4L at 40x18x8cm.

The Ortlieb isn't as uncommonly expensive as you might think, mind you; our Best Bikepacking Bags buyer's guide features the Brooks Scape Frame Bag at £90 and the Wildcat Ocelot Frame Bag at £115.

Also, the 4L version of this bag is £9 more at £110, and the zipped versions are £110 for the 3L and £120 for the 4L.

Overall

This feels very rugged and keeps a useful amount of stuff absolutely dry. It doesn't interfere with bottles and can be tweaked to never interfere with your knees either. You can fit it and never have to think about it again – just use it whatever happens – and that, at least to me, seems ideal.

Verdict

Tough, truly waterproof and extremely useful bag for all conditions