Specialized/Fjallraven Seatbag Harness

The Specialized/Fjallraven Seatbag Harness is one part of a saddle bag system that also includes a separately available drybag. Thanks to its aluminium chassis it's rock solid when you ride, even when loaded up, making it ideal for bikepacking over mixed terrain. It's also compatible with bikes that run a short seatpost. The downside of this system is it does add weight.

For more options, check out our guide to the best bikepacking bags. 

If you're planning a bikepacking trip and you want to mount some luggage under your saddle, there are a plethora of options out there. At its simplest, you can strap a drybag to your seat rails and seatpost. Then there are drybags that are specifically designed for bikes and have attachment points to do so.

There's also the option of a frame support, onto which you mount a bag, such as the Carradice Bagman, and then there's the type we have here: a system consisting of a harness that attaches to your under-saddle, and a drybag that you mount to it.

One of the advantages of this type of system is being able to easily load and unload the bag off the bike.

As far as I'm aware, there aren't many of these out there. Restrap makes them – Stu tested its Race Saddle Bag 7L last year, and Mike had reviewed the 14L Saddle Bag Holster and Dry Bag back in 2017 (as well as the previous version of the Race Saddle Bag in 2020), while over on off-road.cc Matt was very impressed with the Wildcat Tiger Drover Saddle Harness.

By far, this Specialized/Fjallraven offering is the most complex I've seen, featuring an aluminium frame that consists of an upper and lower section, independently connected to accommodate different sized drybags and to allow for some flex in the system. I describe it as a pannier rack that goes on the underside of your saddle. Indeed, it weighs as much, if not more, than some pannier racks at 623g.

The dimensions are 10cm x 45cm x 21cm (HxWxD), so it's quite sizeable, too. It comes in black or green to match or contrast against the accompanying Seatbag Drybag, which I was testing at the same time.

> Beginner’s guide to carrying stuff on your bike

The harness mounts at two points: a single-bolt mount is connected to the seat rails, and this in turn connects to the upper frame rails via two clasps that are bolted to the sides of the mount.

Both the upper and lower frame sections are then attached to the seatpost by way of a simple Velcro strap, with the option of adding a foam spacer if you wish (I added it to help soften any shocks over rough stuff).

Attached to the chassis are two sections of S/F's trademark Vinylon F with a polyamide 210 lining, which serve to prevent the drybag from spilling out from the sides or the bottom. They also house the many straps that allow you to adjust the tightness of the bag, with three either side, and one larger strap at the back. Although the extra straps do make the drybag more secure overall, it does mean it takes a shade longer when unpacking at basecamp; I didn't find this an issue at all, mind.

By way of comparison, Restrap's harness, somewhat ironically given the name of the brand, makes do with just three straps in the small and medium offering, and five in the largest.

The side straps are easy to adjust thanks to the quick-release camlock buckles – pull them as tight as you need, or lift the buckle to gain some slack.

The straps are long enough to easily accommodate a larger dry bag if you wanted, and any excess is taken care of by way of elasticated loops, though I found that with the smaller 10L bag, I had to double tuck the ends of the straps, and at various points they would work their way out on bumpy terrain. Nifty bonus: the compression strap at the rear features a reflective Velcro strap for holstering the excess, adding a bit of low-light visibility.

In use

Admittedly, the system felt a little over-engineered at first, and as I mentioned there's a definite weight to it, but the crucial thing is it really works well. Having tried seatbags in the past, I've always found that they tend to sway around too much and lessen the riding experience somewhat because you know they're always there.

The Seatbag Harness basically completely cures this, because the chassis eliminates any kind of movement. Over the course of a two-day trip over the Black Mountain in Wales, on some of the most steep and rugged terrain I've ever encountered, it was faultless.

For me, the weight is a non-issue because when you're loading up an already heavy steel bike with lots of kit, an extra 600g isn't making a huge difference.

> Your complete guide to bikepacking

The other benefit of this system is it can adapt to different lengths of seatpost: on a longer post it mounts further towards the rear of the upper rails, increasing the angle of the harness, while on a shorter post it mounts further towards the front, making the harness sit more level, with the post mount closer to the seat.

In theory the latter style would be less rigid and could put more stress on the frame. I tried mounting it this way and it seemed pretty rock solid to me, but as I run a long seatpost I didn't test this out over a long distance.

Interestingly, S/F doesn't mention a weight limit for the system, but I'm not really surprised. Personally, I wouldn't ever carry too much under the saddle anyway, but the system is so robust I reckon you could load it up without worry.

Value

The harness costs £120 (from Fjallraven – £125 from Specialized), while the matching drybag is £45 for the 10L version, making it £165 all-in.

The Restrap Saddle Bag mentioned earlier comes in at £109.99/£119.99 for the 8L/14L versions, while the slightly different 18L version is £129.99. All three come with drybags, making them substantially cheaper than the Specialized/Fjallraven Seatbag Harness.

When Mike reviewed the 14L version in 2017 (when it was £20 cheaper!) he noted that the system didn't move unless you really rocked it about, which makes me believe it's not quite as secure as Specialized/Fjallraven's offering, although it scored highly overall in all aspects.

A similar design, Rapha's Waterproof Rear Pack, has gone down in price since off-road.cc reviewed it in 2020; it's now £105 – including the drybag – though Patrick thought it was missing a few features.

A slightly different – and cheaper – alternative is Birzman's Packman Saddle Pack (with waterproof carrier), which is £10 less than Restrap's 8L Saddle Bag, and also comes with a removable 8L drybag. It incorporates a metal carrier that bolts to the saddle rails, acting as the frame for the whole system. When testing it for off-road.cc last year, Ty noted the system was sturdy enough on rough roads.

Cheaper still is the Wildcat Tiger Drover mentioned earlier, which features a simple double-strap harness (much like the Restrap one) that's designed to hold 5-10L drybags. It costs £85, the cheapest here, but as you have to bring your own drybag it might work out around the same as the Birzman (unless you already have a suitable bag).

Conclusion

The Specialized/Fjallraven Seatbag Harness is by far one of the best products I've come across in the whole collaboration lineup. It's totally bombproof off-road, and makes the process of loading or unloading your kit really easy because you can simply take the drybag off, or put it back on, in less than a minute.

This performance comes at a slight weight penalty, and of course there's the price tag, though I don't believe there's anything quite as robustly engineered as this out there.

Verdict

A brilliant, if expensive, saddle bag system that's ready to take anything on