Tailfin Frame Bag

The Tailfin Frame Bag is the result of years of R&D and testing by Tailfin's sponsored riders. Its take on the frame bag comes in nine sizes for a near-custom level of fit, and it's basically everything you'd expect from a Tailfin product: near perfect.

> Buy now: Tailfin 3.5L Wedge Frame bag for £105 from Tailfin

Tailfin's frame bag is designed for road and gravel bike geometries, and comes in nine sizes, from 1.9 to 6.5 litres, covering frame sizes from 47 to 61cm, and setting you back between £95 and £125. They come in either Wedge or Half frame versions – the former optimised for maximum bottle capacity underneath, the latter maximising storage capacity.

We were sent both the 3.8L Half Frame Bag shown in the studio shots and the 3.5L Wedge Frame Bag to review, and I mainly used the latter, so that's the one I've concentrated on here.

I like a bit of bikepacking and have used a fair few frame bags over the years. My main requirements for a frame bag are a decent fit, with space for a big and a small bottle, and narrow enough so I don't rub my legs on the bag. If I'm buying one, I like knowing exactly how the bag will fit and how much space for bottles there will be before spending cash.

After those main requirements, my nice-to-haves would be: easy-to-use zip, a charging port, doesn't get in the way of fitting a top tube bag. I also like the attachment points to not scuff up my frame finish, and not get in the way of any external cable routing stops or ports. It'd be nice if it lasted a long time too.

Tailfin's frame bag ticks all those boxes.

Construction

Tailfin uses a 3D-welded construction. That's marketing speak for a waterproof, tapered design that's specifically designed to minimise knee rub. That waterproofness is reliably confirmed by our Dave, who took one of the frame bags Tailfin sent on his Bryan Chapman audax ride.

To avoid bag sag, the frame bag has an internal carbon space frame. There's also a carbon strut under the zipper on each side, making it very easy to open and close the zips with one hand, and stopping the bag from bulging out too much.

There are what Tailfin calls 'conformity zones' at the front and the back, which means that they've not given the bag structure there so it can mould around the steerer and seat tubes, eking out usage to more frame sizes.

Inside

On the inside, there's all sorts of useful stuff, like a Velcro point at the top to stow a pump or tent/shelter poles. There's a small internal zipped pocket in the main compartment to store valuables, and on the other side of the stretchy divider there's another unzipped one.

The flexibility of the divider works really well; it means you have more options for organising your stuff how you want to, and the divider will conform to whatever shape you stuff in either compartment.

The interior has a light grey colour, which helps when you're trying to find that small thingymabob you're sure you packed.

At the front, there's a Velcro-closed flap, useful for a cable to charge your electronics or for a hydration hose if you like to store your fluids in a frame bag.

One slight downside of the carbon zipper-supporting struts is that they can make it harder to pack odd-shaped items like an action camera on a mount. If this is an issue for you, those carbon struts are removable, through that flap on the front.

Material

The bags are made from 210D Hypalon and 210D Diamond Ripstop, the same material used on Tailfin's Top Tube Bag, high-frequency welded and completely waterproof.

Fitting it to the bike

The frame bag comes with one 290mm and three 185mm TPU Voile-like cargo straps (the two smaller wedge shapes come with two of the shorter straps), and these are used to fit the frame bag to the bike through the V-mounts on the frame bag. This is exactly the same as on the top tube bag, and the V-mount spacing is the same as on the top tube bag, which means the front two straps on the frame bag will double up for top tube holding.

This is hands down the best way to attach a frame bag to a bike. The V-mounts are rubberised, and between those and the TPU straps, the attachment is pretty much bombproof and extremely stable. There is no sway or movement, which also means frame scuff, if not non-existent, is kept to an absolute minimum. The TPU straps have a little 'keeper' thingy, and you can also tuck excess away in the V-mounts for a clean look.

Getting it right the first time can be a little bit of a faff, but once you've got all the straps oriented the right way and there's a bit of a 'memory kink' in the TPU strap showing you which hole to use, it takes less than a minute to attach.

The V-mounts are a bit wider than the TPU straps, giving you a bit of wiggle room to work around cable stops/ports, and the length of the straps should accommodate even the biggest down tubes.

Choosing the right one

The Tailfin website is particularly helpful when it comes to choosing the right size frame bag to go in your frame, which for me means enough storage capacity, fitting correctly, looking right and being able to get my bottles out of their cages without too much hindrance from the bag.

You can either go for straight-up measurements, or if you have access to a printer, Tailfin provides printable templates. In typical Tailfin fashion, these are provided in A2 format, ready to cut out, or in A4 and letter formats to print on a printer size you are more likely to have access to, which will require some cutting and pasting.

The A4 templates have a ruler so you can double-check the scaling is right, and cut marks for accurate assembly. A couple of measurements, and comparing with the actual frame bag confirm that the templates are true to size.

Tailfin has also put together a Frame Bag Sizing Tool. Take a picture of your bike with mudguards removed from a specific distance, upload it to the tool, specify your tyre size and the tool lets you superimpose each of the size and shape variations onto your frame. When you take the picture of your frame, make sure you have your preferred bottle combination on, and you can check bottle clearances too.

The sizing tool is a great idea, but I didn't find it perfectly accurate. Sizing the 3.8L Half Frame Bag on my Tripster frame with the tool suggests that it will work just right in my frame with just enough bottle clearance.

Comparing that to the actual frame bag in my frame shows that that is a little optimistic. Using the printable template is much more true to reality.

If I'd only used the sizing tool in the purchasing process, I'd have gone for the 3.8L Half Frame size and would have been disappointed when it arrived. As it happens, the 3.5L Wedge size works much better. When I mentioned this to Tailfin, it sounded like there is some ongoing development with the tool. Worth checking against the printable templates in my opinion.

Weight & value

The 4.5L Half Frame Bag is the same size as Restrap's Race Frame Bag Large that I reviewed a couple of years ago, but is significantly heavier at a claimed 350g, including the TPU straps, than the Restrap at 236g.

Weight isn't everything, though, unless you're going ultralight and want to get somewhere as fast as possible. I liked the Restrap a lot; I gave it 9/10 and it earned a road.cc Recommends badge. It was a serious contender for best-in-class frame bag at the time. Suffice to say the Tailfin knocks it out of the park and is in a whole other league.

At £94.99 that Restrap Race Frame Bag Large is also cheaper than the 4.5L Half Frame Bag, which will set you back £115, as is Apidura's Expedition Frame Pack at £95 (4.5L) and its Racing Frame Pack is yours for £103.

None of the above come in the same range of sizes, though, so I think it's fair to also add in some prices for custom frame bags: Restrap custom start at £119.99 for a small full frame bag. The full-size Alpkit Stingray starts at £129.99. Straight Cut Design wants you to book a £50 phone consultation for its custom frame bags, which then start at £150 for its partial frame bag.

Cheaper frame bags are available: the Alpkit Deluge Frame Pack costs £49.99 for a 4L volume, and Lomo's Bike Frame Dry Bag costs even less at £26 for a volume John guessed at around three litres.

Conclusion

There is a lot to like here: no knee rub, one-handed easy zipper opening and closing, a stable fit without frame scuff, durable materials, and it helps that it looks good too. Add in the fact that you should be able to find one that fits all but the most esoteric of frame shapes and sizes, and that you can check this easily from home before you buy, makes this the best frame bag you can buy, in my opinion. It's a little pricier, but also a lot better, than other options. The only reason I can see why you might look elsewhere is if weight is your primary concern.

Verdict

Best-in-class frame bag available in nine sizes – you should be able to find an ideal one for your needs