Hi, we're Pam and Gilbert of 2 Bikes 4 Adventure. We've been carrying our gear on folding
bikes for both day trips and multi-week tours for many years. We've always started with a bag that
clicks onto the Brompton front carrier block. These front mounted bags are simple and easy to use
but there is another option that we haven't previously explored in depth, the rack bag.
Some of the advantages of a rack mounted bag on a Brompton include: practical amount of capacity
for commuting or day tripping, extra capacity for longer trips as an addition to a front bag,
a wide range of models available, can be used on multiple bicycles not only Brompton,
usually better value per volume cost per cubic inch or per liter and less costly than front bags.
The disadvantages of a rack bag: a rear rack is a necessity,
the bag needs to be removed to fold the bicycle, it cannot be easily accessed while cycling
and is out of view while cycling thus possibly less secure in some environments.
The Brompton is less stable if too much weight is added at the back. In this video we'll compare
two popular solutions in the 100 to 120 dollar range and rate them on the following factors:
mounting system, storage capacity, durability, ease of use and weatherproofing.
While our front bags are Brompton specific because they attach to the mounting block,
a rack bag is usually designed for generic or specific racks
instead of the bike. We have to ensure that the length and position of the attach points
on our choice of rack bag is compatible with the rather unconventional Brompton rack dimensions.
The mounting system should provide a secure attachment and enable quick removal when folding the bike.
In addition to the volume available in the main compartment, additional features
may include expandable capacity, interior and exterior pockets and external attach points.
Fabric durability is often rated based on tensile strength and abrasion resistance. Most outdoor bags
are made of either polyester or nylon. Nylon is considered stronger but it takes longer to dry.
Note that Cordura, which is a trademark technology for durable and abrasion resistant fabric, is made
of nylon. The thickness of the selected fiber also plays a key role in the durability of the bag.
Measured in denier abbreviated with the letter D it represents the weight and grams of a 9000
meter long fiber. Common values are 400D, 500D, 600D and 1000D. The higher the number,
the stronger the fiber. For example, military grade bags are usually made of 1000D Cordura
while a less rugged everyday backpack or pannier could be manufactured a 500 or 600D polyester.
Although stronger could be better, the actual choice should depend on your budget and
intended use. While a 600d polyester bag could be sufficient for a daily commute,
a month-long journey that includes camping would benefit from 1000D Cordura.
Zippers are often the first thing to fail in luggage and bicycle bags are no exception.
Most utilize coil type zippers which are more robust than their metal or plastic counterparts.
Zipper size refers to its width in millimeters, a larger width should be more robust.
An invisible zipper has the coil mounted at the back of the zipper,
this does not mean that it is waterproof but it should be dust resistant.
The bag should be easy to carry off the bike using a comfortable handle or shoulder strap or both.
Glove friendly zipper pulls, a large opening a light colored interior and external attach points
are features that can make it easy to use a bag on and off the bike.
These bags will be out in all weather conditions. Weatherproofing can range from negligible through
an IP rating of 3 or higher, the most cost effective solutions involve a rain cover.
First, we'll look at the Brompton Rack Sack. Its mounting system is mostly Brompton specific.
While secure enough once attached, it's rather underwhelming when compared to
the efficiency of the front carrier block. It involves a loop around the suspension block,
a velcro strap around the seat post and a clip buckle twisted around the rear rack.
Because the loop and strap cannot be tightened, some rattling may occur between the bag and
the rear rack while in motion. It does what it's intended to do but would not win a design contest.
It will fit only Brompton or Brompton-inspired bikes.
Basically unchanged for more than a decade, its 16 liter capacity makes the Rack Sack one of the
roomiest options available. It consists of a simple large padded compartment and is more utilitarian
in design than most of the other solutions on the market. There is a zipper at the bottom of the bag
but don't plan on using it for storage. It was used to insert the padding during the manufacturing
process and is not advertised as a pocket. Maybe you could hide some cash or a small item in there
but it might be tricky to retrieve in case of emergency if the pocket contents have shifted.
There is a small external pocket at the front but for some unknown reason,
the stitches at the bottom of the pocket do not cover the entire width of the bag, thus small items
would fall out while cycling making it useless for storage. The bag is constructed with Cordura 1000D
and YKK zipper #10. Its simple and rugged design will likely survive any adventure
short or extended. It's as bomb proof as the Brompton it was designed to be attached to.
It comes with a basic carry handle and a removable shoulder strap.
Our older model has a lockable zipper but later models come with glove friendly zipper pulls.
The interior is lined with light colored fabric yellow or gray, depending on the
year it was manufactured. This can facilitate finding small items at the bottom of the bag.
The bag's large size could make it awkward to use on a daily commute via public transit.
This bag is more suited to a long touring adventure than a busy urban setting.
The reflective strap surrounding the bag and the small tab to insert a rear reflector,
increase visibility in dark conditions. The Rack Sack doesn't come with a rain cover.
Its Cordura fabric is treated to be water resistant but would likely get soaked in a serious shower.
Any water sensitive items would need to be bagged separately. Next, we'll look at the Vincita Nash bag.
The Nash bag's mounting system is based around the UniKlip universal quick release mechanism from
KlickFix. Rated to a maximum of 10 kilograms, it can be installed on a variety of racks of various
shapes and forms and is not specifically designed for the Brompton. Prior to initial installation,
the support rails need to be adjusted to the rack width. This is done by loosening
four screws and moving the rails laterally so that they correspond to the bicycle rack width
for a range between 9 and 16 centimeters. The Brompton rack varies from 14 to 15 centimeters.
The instruction leaflet includes a printed scale to help with the installation process.
Scaled markings are etched at the bottom of the bag's transversal support
to facilitate the adjustment. When the proper width is set, the screws can be tightened again.
This mechanical adjustment needs to be done only once for a specific bike.
When installing the bag, ensure the support tab is positioned in front of the rear cross brace
and rotate both side levers downward to secure the bag in place, they will automatically adapt to any
rack structure between 8 and 16 millimeters thick, the Brompton is 13 millimeters thick.
The UniKlip also features an anti-theft latch to prevent prying hands from removing your bag when
you're not looking. By inserting the provided security key into the red recess, we can move
a latch into a locked position. Sliding in the opposite direction easily unlocks the mechanism.
The ease with which the bag can be installed and removed is a major advantage.
Considering that the retail price of the standalone UniKlip system is around
$US50, it likely represents 50% of the manufacturing cost of the Nash bag.
If you value a quick and efficient way to install and remove your bag, this is the solution for you.
The main compartment of the Nash bag is about 11 liters (680 cubic inches) but it includes two side
pockets that can be extended when needed to increase the total volume to 17 liters.
Held in position using provided small bungees, these pockets are designed to avoid heel strike.
However when full, they could interfere with the installation and removal of the Nash
and make the bag more awkward to carry or lay on the ground.
When stowed these side pockets cannot realistically be used for storage. The interior
lining is removable and can be adjusted using the dividers provided, similar to a camera bag.
The Nash bag is made of 600D polyester and its zippers are YKK#6.
The previously mentioned mounting mechanism makes the Nash bag easy to install and remove.
It has a well padded carry handle and a removable shoulder strap.
The dark lining of the interior may make it more difficult to find small items inside,
it could benefit from a lighter color such as those found in some other Vincita bags.
The central zipped opening is not as practical as a U-shaped opening,
a rectangle flap would make it much easier to insert and extract larger items.
Glove friendly zipper pulls are installed on the side pockets hidden zippers
but not on the main compartment zipper. Reflective decals on the side pockets help with visibility.
A tab can be used to attach a small rear reflector. The Nash bag comes with a rain
cover. It is shaped to accommodate the bag even with the side pockets deployed.
Let's review the scorecard. The Nash bag wins big for its mounting mechanism.
It's much simpler and faster to attach and remove. It missed a perfect score only because
the screwdriver is needed to adjust the UniKlip when switching the bag from one bicycle to another.
Both bags mount securely, but the Nash anti-theft mechanism deserves the full 10 points.
The capability to install the Nash on various bicycles earns it an additional 5 points.
The Rack Sack's main volume is greater but with the side pockets deployed the Nash provides a
similar capacity. Neither bag has external attach points. Fabric, zippers and general construction are
more rugged on the Brompton bag. It could better withstand a harsh touring environment. The Nash bag
is made for a more urban and, can we say, design conscious environment.
The superior carrying handle provided by the Nash gives it a one point lead. The zipper pull,
interior color and large opening make access to the main compartment easier on the Brompton bag.
Both bags have a tab to clip on a reflector as well as reflective surfaces. The Brompton's
cover a wider area. A fully waterproof bag would have earned 15 points. The Nash rain cover wins
10 points and the Cordura water resistant treatment on the Brompton only five points.
For daily or week-end adventures, the Nash bag should provide years of good service.
For months-long touring adventures under difficult conditions, we would likely favor the Brompton bag.
We wish to thank Vincita for providing the Nash bag for our honest evaluation.
We hope that you consider how much a rack bag can add to your folding bike adventures.