Bontrager MIK Utility Trunk Bag

The Bontrager MIK Utility Trunk Bag is a tidy way of carrying gear and knick-knacks and keeping them all organised and able to be quickly popped on and off your bike.

If you're an organised type, Bontrager has you covered with the MIK Utility Trunk Bag. It has the obvious large main compartment, plus four side pockets (each side has an expandable large pocket with a smaller flat pocket outboard of it). On top there's a soft-lined pocket for your sunglasses and an elastic cord for a jacket, plus there's a mesh pocket inside the lid.

> Buy now: Bontrager MIK Utility Trunk Bag for £97.89 from Swinnerton Cycles

Mounting the MIK Utility Trunk Bag to a compatible rack is a doddle: you just slide the bag into place on a MIK-compatible rack until it clicks. To release it, you use the included MIK stick to push the latch open. You don't even need the stick; you can just reach under the bag and push the catch open.

Pull the bag off the bike and there's a built-in handle to carry it around, and Bontrager throws in a shoulder strap that clips into D-rings on the bag for a comfier, hands-free carry.

Once the MIK Utility Trunk Bag is in place, it's not going anywhere. The mechanism's grip on the rack is tenacious and the bag is very stable as a result.

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The Bontrager MIK Utility Trunk Bag swallows a lot of stuff for its nominal 13-litre capacity. Jackets, spares, food, other clothing and more all vanished into its TARDIS-like interior. It helps that the large side pockets are very flexible so can really be crammed with extra stuff if necessary.

It's also fairly water-resistant, though in theory water could get in from underneath through the holes in the base where the attachment hardware fits. Unlike its stablemate the MIK Commuter Boot Bag, it doesn't have an internal waterproof liner, so if keeping your kit dry is your absolute priority, that's the bag to go for. If it's tipping down there's a waterproof rain cover tucked into a front pocket.

Perhaps the MIK Utility Trunk Bag's biggest disadvantage is that there isn't quite enough room inside it for a large U-lock. If you want to carry, say, a 30cm Abus Granit XPlus you'll have to take the lock housing off the shackle. This is irritating because if the main compartment were just a little bit bigger the lock would pop straight in.

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Over time the Trunk Bag's side pockets have gotten a bit saggy. It doesn't affect the use at all, especially if you stuff it with clothes or whatever so the shape is supported, it just looks a bit off.

Taking the MIK?

Let's take a broader look at the MIK attachment system here. It isn't proprietary to Bontrager but was developed by Netherlands bike luggage company Basil and Taiwanese accessory maker Massload as a quick and easy-to-use method of mounting bags, baskets and crates on top of a rack. Very much a niche application but one that previously involved tedious faffing with Velcro straps; MIK (it stands for Mounting Is Key) is a definite improvement.

The danger with a system like this is that the manufacturer will stop making it and you'll be left with a bag you can't replace. Basil has been using MIK for several years now so it seems likely to stick around.

If you already have a rack that's not MIK-compatible, you can get a MIK Carrier Plate for £17. Note that this is NOT the same as the MIK Adapter Plate which you use to convert an existing bag, basket, crate or box to the MIK system.

Bontrager says that the MIK system 'locks your bags to your rack to prevent theft'. Yeah... no. It's so trivially easy to release a MIK bag from the rack even without the MIK stick that this claim is just silly. In fact on its page for the MIK stick, Basil says: 'The MIK stick ... does not protect the accessories against theft.'

In fact, rather than carry the MIK stick around separately or leave it in place and risk it falling out, I tightened the 3mm hex key grub screw in the latch to mount the stick permanently in place.

With a MIK bag in place on a standard MIK rack like the Bontrager BackRack MIK, you can't really use your rack's top bars to carry a pannier. Bontrager makes a rack – the BackRack Deluxe MIK – with an extra bar to hook your panniers on, so if you're going to start with the MIK system, buy that one. Alternatively, with a non-MIK rack and the MIK Carrier Plate you can fit MIK Pannier Bag Tubes to take panniers.

I like the MIK system as a way of quickly fitting and removing a top bag, but it's a pity Basil and Massload didn't think a bit more about making it a complete system to accommodate panniers as efficiently as it accommodates a top bag.

Rivals

There are several click-on-to-rack systems vying for your top-bag money. Topeak's long-established MTX system offers the MTX TrunkBag DX, which is very good and quite a bit cheaper than the Bontrager bag. The Racktime system from Germany also includes top-bags for less money than this one, and Basil offers the Trunk Bag MIK for £91, though you can get it for £68.

Who should buy the Bontrager MIK Utility Trunk Bag?

This is a very good bag for cyclists who need to carry a moderate amount of stuff and want to be able to quickly and easily fit and detach a bag from the bike. That's a pretty big range of use cases: commuter and other utility cyclists, countryside explorers, touring-style day trippers, and audax riders.

Conclusion

Overall, if you're willing to commit to the MIK system, this is a very handy bag that'll swallow everything you need for a day ride, and can be removed and fitted easily and quickly.

Verdict

Excellent rack-top bag for the MIK click-on mounting system