Reviews – Topeak MTX TrunkBag DXP & Topeak Explorer Tubular Rack


With bags and packs in general – biking or otherwise; I think there are three important main points to consider.

Firstly, it should have at least one large storage area.  It can be configurable to have partitions to give it the ability to be divided into smaller sections but having at least one large storage area is important.  Because you never know what you need to carry and if it’s too big for the bag you can’t make it magically larger.

And secondly there should be plenty of compartments for medium-sized and smaller items that you want to organize and have fairly quick access to without pawing through the aforementioned large compartment(s).

Thirdly the bag has to be durable.

The Topeak MTX Trunkbag DXP for bicycles fits these parameters quite well.  As a bonus this bag is made to attach to the matching Explorer Rack from Topeak with a simple sliding mechanism instead of by other, more conventional straps, loops, clips, velcro or bungees that are sometimes used to secure a bike bag.

topeackcarrier02So I decided to review these two items together as they are made to fit each other (and other Topeak equipment).  The bike rack could be used with many other bags and panniers if needed and with a little creative strapping the bag could be used on other bike racks too, I believe.

The Trunkbag and the Explorer Rack were acquired by my wife from a LBS (Black River Adventurer’s Shop) after winning a generous $200 gift certificate after the Sackets Harbor Spokerride (sponsored by Samaritan Health Center, benefiting Livestrong and the American Cancer Society.)

I personally have a couple of bike racks and a number of bike bags so I know a bit about them, I suppose.  A quick mention here – I have the el cheapo Schwinn Alloy Bike Rack that attaches to the seat post as well as a Ventura Universal Bike Rack that I attached to my bike, which does not have eyelets on it – that blog post is about how to attach a rack to a bike in that particular case.  I also have a lot of bike bags of various sizes for long journeys and for transporting items to and from places.  I generally like to ride with just a seat bag (with tools) and cellphone case – see my blog post “What’s (in) Your Seat Bag“, but it’s nice to have more bike bags, for both of us, as needed – for lunch, extra supplies for long trips, groceries, or for hauling pretty much anything.


Bike rack (top), bike bag (bottom) and rail system.

The Explorer Rack from Topeak (without the spring – you can get some with the spring, which from what I understand is made for older style saddlebags; what else can you stick under that spring but maybe a thing magazine or something?) is your standard bike rack, fairly heavy-duty with a fifty-five pound capacity and made from hollow tubular aluminum alloy, with enough support on either side for heavy-duty panniers if needed.  It’s relatively light at just over one and a third pounds (625 grams).  And it’s compatible with any of Topeak’s MTX TrunkBags and MTX baskets via a simple rail system and big yellow locking button at the front.  The rail system is on either side of a solid middle section which might act as a fender for the rear wheel if you’re riding in wet or muddy conditions, if you don’t have a bag on top of it to block the effluvia.

On the back is a place for mounting lights, and the rack comes with various bits of mounting hardware for a few different kinds of lights, including RedLite series from Topeak.  With some cobbling it will fit pretty much any light or reflector as there are a number of holes for mounting.

The rack fits pretty much any bike in the  26″, 27.5″(650B) & 700c wheel size range due to a pair of long mounting arms that can be bent and shaped as needed.  They aren’t pretty – they’re bare silver metal which in no way matches the rest of the bike rack.  But they do the job, and they can always be painted.  For smaller bikes Topeak sells extra long mounting arms.

Attaching the whole thing to the bike is pretty straightforward and simple enough, a little bending of the long arms and some adjustments and re-adjustments – which is going to be different from bike to bike.  It mounts pretty much like you would expect it to, similar to other bike racks with the arms attaching to the upper seat stay eyelets via included hardware, and the ‘legs’ of the rack attaching to the lower seat stays via regular bike allen bolts through the threaded holes at the hub above the dropouts.  Mostly it was a matter of making sure it was level and the arms did not interfere with the brake action, as well as nothing got scratched while measuring and adjusting.

It’s a fine bike rack, standard fare really.

At the bottom of this post you will see the bag and rack installed on my bike – which does not have the upper eyelets for a rack.  A system to attach as bike rack to a bike without the mounts can be easily installed – see this blog post for how to do it.

On to the bag…  One look at the Topeak MTX Trunkbag will tell you that it is nicely built – though you will find superficially similar clones of it that aren’t as high quality looking when you take a closer glance.  The Topeak text and font are proudly embossed across the sides.

topeackcarrier10The quick mount system makes it very easy to slide on and off the above Topeak matching bike rack.  Sliding on and off is just that easy; slide it on until it snaps.  To take it off there is a big yellow button to push and the bag slides out the back.  The only problem with this system is that there is a slight rattle when the bag is empty.  It’s slightly annoying but I suspect a little padding underneath might solve this, I have yet to give it a try.  And this may be just the angle or way it is mounted on my wife’s bike, another few degrees here and there could mean the difference between a little rattle and none at all – just guessing here though.

The basic non-expanded bag is 14.1” x 9.8” x 8.5” (36 x 25 x 21.5) and is a semi-hard shell made of 600 Denier Polyester; the good stuff.  It makes it water-resistant – which means if you are out in a terrible downpour it’s going to take quite some time to soak through (especially since it is also slightly insulated), but you might want to eventually cover it with a plastic bag or generic bag cover, or the optional Topeak bag cover.  And if you do get stuck out in dark conditions there is a 3m reflective strip on the back and sides.

Also included is a padded shoulder strap that you can attach (and carry in the bag when not attached to it) so that the bag can be slid off the rack and carried as needed, and there is also a heavy-duty handle on the top of the bag.  On the back is a place for a tail light or reflector (in addition to the mount for a tail light on the Topeak bike rack itself).  The whole bag only weighs just over two and half pounds or 1160 grams.

Inside; accessed via a heavy-duty zipper system, there is a big open space – 22.6 liters overall (including the space in the side pockets), some dividers, and side and top pockets as well as a bottle carrier in the back, with mesh and an elastic bungee across the top.  You’ll find pockets and storage sleeves all over this bag. The whole thing is pretty well padded, with molded EVA foam insulation so if you did have something in there that needs to be kept cool or warm there is going to be some insulating properties as well as protection from the elements.  The top itself expands upward, unzipping and hinging at the front.


The side pockets have a fair amount of room for things, even stuff like bananas or cucumbers or something else that are wider than the pockets – yea, you can bulge ’em out, it’ll take it.  The panniers are also folded up into these side pockets.  The panniers/saddlebags can be quickly deployed and refolded back in as needed, and have little bungee attachments at the bottoms to secure the bottom part of each to the bike rack legs near the bottom.  So the bottoms of the panniers don’t flop back and forth and get into the wheel or something, especially with stuff stowed in them.  They are surprisingly easy to get opened up and while they are not very heavy-duty (I assume that you’re not going to be packing for an adventure cross-country with this set up), they do give you a lot of extra room for a day trip or some groceries from the store.  The material is tough but fairly thin on the pannier bags so there’s not much in the way of insulation of heavy-duty protection for anything in them, unlike the bag itself.  Good for straight hauling.


The bag is quite large, and if you have the bike rack mounted fairly close to the seat and you ride quite far back on your saddle you may feel the back of your butt up against the front of the bag, though this depends completely on your set up and bike of course, and personal preferences.  But you should be able to adjust it via the bendable arms on the upper seat stays.

It wasn’t hard getting the rack fairly level with the ground as well as the bike, but it is a few minutes of careful bending of the support arms.  Slowly, and if possible with something like a pail under them to give them a gentle curve if needed.


The Topeak MTX Trunkbag DXP is especially good quality and a great bag, and the Topeak Explorer Rack is a pretty good bike rack. My only complaints would be that the rail mounting system rattles a bit, and the arms for the bike rack could be engineered somewhat differently – perhaps just for cosmetic sake.

But these are minor quibbles and don’t affect the functional of either item, nor how they work together.

They might be considered a bit pricey (both together right now – 11/4/16- would be around $130) compared to their clones, but here’s a case where the quality is pretty obviously clear. 

So if you are in the market for a good-sized bag and a bike rack the Topeak MTX Trunkbag DXP and Topeak Explorer Bike Rack might just fit the bill.


Bag and rack mounted on my bike, saddlebags extended


Marc M

I am a web developer and fitness geek, but I have a heck of a lot of differing interests.  Biking, the Internet, technology, movies, fitness, running and walking and hiking, science fiction, photography, graphics, WordPress, flying and aircrafts, pets and animals, history, and much more.  I like to stay very fit but I don’t mind sitting at my computer for work and play either.  I live in upstate New York (that’s far from New York City) in a rural area, yet close to a small city, with my beautiful awesome wife, a bunch of beloved cats and dogs and chickens in a very old multi-century house.

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