The Brompton C Line Explorer or the Dahon Mariner D8. Which folding bike is right for you?
To help with the decision, we created an evaluation grid and assigned points to the following
characteristics: Cost, Foldability, Ride Quality, Maintenance, Reliability and Luggage capacity.
Of course, the relative weight for each characteristic will depend on the rider's priorities. For example,
foldability would be paramount for a commuter while a casual rider may be more budget driven.
As of November 2022, Amazon was quoting $1400 US for a Brompton C Explore,
20% saving over the regular price. A rear rack would add about $200 to the total.
The Mariner D8 costs about $900. Amazon is presently advertising a 40th anniversary
special edition for about $600, but it does have some scaled down components.
Special edition or not, the Mariner is substantially cheaper than the
Brompton. We give 8 points to the Brompton and 15 to the Mariner.
We will break down foldability into Ease of Folding for 5 points and folded Size for 15.
The Mariner mechanism is quite conventional and relatively intuitive for a newcomer.
While Dahon advertises 15 seconds folding time, in our experience, 30 seconds is more accurate.
The Brompton is less intuitive, but with experience, folding can be performed very
quickly, most likely in less than 10 seconds. We give 4 points to Brompton and 3 to Dahon.
While the weights of both bikes are similar at 12.5 Kg, the total package of
the folded Mariner is almost twice as bulky as the Brompton, mainly due to the Mariner's larger
tire size and the folding mechanism. Carrying a folded Mariner on crowded public transport could
be awkward for fellow commuters whereas carrying a Brompton were more likely raise friendly questions:
It's a folding bike? How much does a weigh when it's folded? The Brompton is in a league
of its own, designed for multimodal travel, it can easily be used for bus, train, ferry or air travel.
Because of its small size, we can avoid paying any extra fee normally charged for a bicycle.
The Dahon folded characteristics are better leveraged when traveling by car for the occasional trail ride.
Air travel with a Mariner will probably involve an extra fee for oversized luggage or some serious
disassembly. This brings a total for foldability to 18 points out of 20 for the Brompton and 12
for the Dahon. We'll break down ride quality into 4 characteristics of five points each:
Bike Fitting, Gearing, Brakes and Comfort. While both bikes only offer one frame size, Brompton
offers various length seat post options that could be important for a taller rider.
On the other hand, the Mariner has an adjustable stem that offers better control over the
bicycle stack instead of having to decide between handlebar S, M or H at purchase time.
As for stability, the Mariner's wider handlebar compensates for a smaller wheelbase.
We assigned 2 points out of five for the Brompton and 3 out of five for the Dahon.
Both bikes offer a relatively similar gear range of 300%, roughly between 30 and 90 gear-inches
or 2.4 and 7.2 meters of development. The approach is quite different however. The Brompton
uses a hybrid solution with a three-speed Sturmey Archer internal Hub attached to a proprietary
two sprocket derailleur while our Mariner offers a more conventional Shimano Altus 8-speed derailleur.
The Brompton shifters have a tendency to jam, which is difficult to justify on a bicycle of this price.
For more detail the Brompton Traveler Channel has an excellent video on the subject.
The Mariner Shimano trigger shifter is literally decades ahead of the Brompton.
We give 2 points to the Brompton and 4 to the Mariner. Brompton uses proprietary dual pivot
asymmetric calliper brakes while the Mariner has the more generic, and probably economical, V-brake.
By design, the V-brake offers more tire clearance and better mechanical advantage, but ultimately,
the fork and rear triangle limit the size of the tire installed more than the brake system does.
As we showed in a previous video, smaller wheels are more prone to overheating and
heavy braking conditions. We can expect the Mariner brakes to perform better during descent.
For most users however, both types of brakes should be adequate so 3 points out of five for each.
For a properly fitted fitted bicycle, riding comfort is mostly associated with the amount
of vibration that is transmitted from the road surface to the rider.
Because the steel of the Brompton's frame is a more compliant material than aluminum, it gives
a small advantage. However, the most significant difference for comfort is the tire. With its larger
width and diameter, the Mariner 20 inch tire offers 70% more air volume compared to the 16 inch
Brompton tire. Correspondingly, its recommended inflation pressure is half of the Brompton's.
To simplify the effect a tire has in insulating the rider from road vibrations, we can model it as a
spring connecting the hub to the road surface. The stiffness of the spring, also known as spring rate,
being directly proportional to the tire pressure. When riding over obstacles, the Brompton tire,
with this high spring rate, is more likely to transmit high frequency vibration to the rider
than the softer Mariner tire. One way Brompton improved its overall suspension is through the
addition of a rear polyurethane suspension block. The resulting rear triangle's vertical
travel contributes to insulating the rider from small road irregularities. On a smooth
surface, the difference in comfort between the bikes is not very noticeable. In fact it, may
even favor the Brompton, but on poorly maintained streets or gravel roads, the Brompton's riding
comfort deteriorates quickly, despite the damping effect provided by the rear suspension block.
We give 2 points to the Brompton and 4 to the Mariner, for total riding quality of 9 vs 14.
Tires are often the first items to be replaced in the life of a bicycle. With the recent introduction of
newer 16-inch tires from Schwalbe and Continental, there's now a wider range available for Brompton
size wheels. Nonetheless, 20 inch tires have more options and may be more easily available. Trying
to find a 16 inch replacement tire while on the road would be more challenging compared to finding
a 20 inch tire. Because of this, we give 3 points to the Brompton and 4 to the Mariner.
A Brompton consists mostly of proprietary parts. Except for low-level consumable items like tire, tube,
cable, brake pad and chain, proprietary parts will probably be necessary if a serious failure occurs.
Dahon also relies on some proprietary design, for example the main frame hinge and stem folding
mechanism, but it remains relatively easy to fix or upgraded a home bike with third-party components.
Two points for Brompton, 3 for Dahon. On the flip side, the Brompton support network is excellent.
Older parts are still available (some parts haven't changed in years thanks to the slow evolution of
the design). Furthermore, if you're lucky enough to have a Brompton dealer nearby, maintenance
and spare part replacement will be relatively pain-free. Dahon dealerships and online spare
parts availability could be an issue, depending where you're located. Five points for Brompton
after sales support and 2 points for Dahon, which brings both totals to 10 points out of 15.
Both bikes are configured for a rear rack. The versatile Brompton front carrier block
ecosystem does give it the edge. There are bags available for all kinds of use cases, from
waterproof touring to trendy commuting. We give 8 points to Brompton and 6 to the Mariner.
Folding bikes, with their added hinges and folding mechanisms, may be more fragile than regular
full-size bikes and require additional care (the Brompton seatpost sleeve replacement comes to mind).
With proper maintenance, they should retain their resale value, especially models that
are relatively timeless, like the Brompton. Our older Bromptons were purchased used eight years
ago for $500 U.S and we're confident we could resell these 2001 T3s for the same price today.
Through the years, we haven't needed many repairs on either our Bromptons nor our Dahon, although we
did lose the closing magnet on two Dahon, the D5 and the Mariner, and broke a spoke on the D5.
Bromptons are not immune to losing parts either, as those who lost their seat tube bung
or handlebar catch can attest. Overall, we would give the advantage to Brompton for reliability
and resale value: 12 points, with 10 points to the Mariner. When we tally the score, the Dahon
has a small lead over the Brompton, mainly due to Purchase Price and Riding Comfort.
The Brompton wins big and Foldability, also leading in long-term investment and luggage carrying capacity.
Ultimately, your usage scenario and budget should determine your purchase decision. As you increase
the emphasis on any particular factor, for example folded size, the clear choice may be different.
If your main purpose is recreational cycling on various terrain surfaces and occasional multi-day
rides, potentially reaching your starting point by car or maybe by train, the 20-inch Dahon Mariner
could be an excellent fit. If money is no-object and the logistics surrounding multimodal or air
travel are a primary concern, at the possible expense of riding comfort, then the Brompton is
for you. As for us, we will continue to use both, depending on trail conditions, location and trip
duration. If you see us on the road, Pam and Gilbert of 2Bikes4Adventure, stop us for a chat
to discuss your favorite bicycle. Until then, we'd like to hear your opinion in the comments section.