If you’re shopping for a folding bike, your search has likely lead you to compare the Dahon Mariner D7 vs D8. And while you can’t really go wrong with either model, through our research we’ve found the Mariner D8 is overall a better buy in terms of rideability, ease-of-use, and quality of components.
Of course, the upgrades found on the Dahon Mariner D8 come at a price, but as you’ll see in our review, are definitely worth it if you’re in the market for a folding bike that will take you on many enjoyable commutes.
Table of Contents
Quick Look: Comparison Table
| Dahon Mariner D7 | Dahon Mariner D8 | |
|---|---|---|
 |
  |
|
| Best for | Urban Biking | Urban Biking with hillier terrain |
| Price | See Price on Amazon | See Price on Amazon |
| Frame Material | 4130 Chromoly Steel | Dalloy Sonus (proprietary to Dahon) |
| Weight | 26 pounds | 26 pounds |
| Gears | 7 | 8 |
| Derailleur | Shimano RD-TX35 | Shimano RD-M310 |
| Shifter Style | Twist Shift | Trigger Shift |
| Assembly | Assembly Required | Assembly Required |
Frame Material: Aluminum vs Steel
Both the Mariner D7 and Mariner D8 have the same frame designs, dimensions, and geometry. The main difference between the two bikes comes down to frame material.
The Dahon Mariner D7 has a steel frame made of 4130 Chromoly steel, a bike frame material used across the industry known for its durability, quality, and relatively light weight. Steel frame bikes typically absorb more road vibrations than aluminum or carbon fiber frames, resulting in an overall smoother ride—a big plus for the Mariner D7.
The Mariner D8 feature’s Dahon proprietary frame material called “Dalloy Sonus,” which is an aluminum-based alloy. While aluminum bike frames don’t offer quite the same smoothness in ride as steel, they’re typically more responsive giving you a better “feel” of the road.
In terms of rideability, you can expect the Mariner D8’s aluminum frame to offer a tighter, snappier feel than the Mariner D7. But if you often encounter bumpy sidewalks, cobblestone streets, or gravel roads on your commute. the Mariner D7 with its steel frame might be a better choice.
In terms of bike weight, it would seem that the Mariner D8 would be lighter thanks to its aluminum frame. But according to Dahon’s website, the differences between the bike’s weight are negligible as both the Mariner D7 and D8 weigh 26 pounds.
Number of Gears: 7 vs 8
As their names imply, the Mariner D7 has seven gears while the Mariner D8 has eight gears. Aside from a few other factors such as frame material and specific components, the number of gears is one of the primary differences between these two folding bike models.
On the road, the Mariner D8’s higher gear count will give you more versatility when riding terrain with varying degrees of steepness. With more gears to choose from, you’ll be able to ride faster on flat land and have an easier time pedaling up steep hills.
To be fair, the seven gears on the Mariner D7 should be adequate for most terrain urban bike commuters encounter.
But if you live in a hilly city, the Mariner D8 is an overall better choice to make your daily commute easier and give you the advantage when tackling hills.
Another gearing-related advantage that both bikes are bringing to the table is the fact that they use traditional drivetrains instead of internal-geared hubs. While you can’t change gears from a stop like you can with internal hub folding bikes, by using traditional sprockets, derailleurs, and chains the Mariner D7 and D8 are easy to maintain and parts are readily available and inexpensive if repairs are ever needed.
Rear Derailleur: Shimano RD-TX35 vs RD-M310
Both Dahon Mariner models feature Shimano rear derailleurs that are designed for use on mountain bikes, which means they should be plenty durable for urban commuting. But just because they are both manufactured by Shimano doesn’t mean they are created equal.
So which is better?
The Mariner D7 features a Shimano RD-TX35 rear derailleur which is a member of Shimano’s “Tourney” line of components. Shimano’s components are divided into a hierarchy of “families” that represent varying levels of quality and performance. It turns out, the Tourney is the lowest tier offered by the Japanese bike component giant.
On the other hand, the Mariner D8 features a Shimano RD-M310 which is part of Shimano’s “Altus” line of components—a few steps up from the Tourney and overall a better derailleur.
Since a bike’s rear derailleur does the bulk of the work when shifting gears, the upgraded Altus derailleur on the Mariner D8 is kind of a big deal. When compared side by side, you should find that the Mariner D8 shifts smoother and more reliably than the Mariner D7. And since it’s a higher-quality derailleur, you can also expect it to be more durable.
Shifter Style: Twist vs Trigger
While the rear derailleur is what moves the chain from gear to gear, the shifter is what initiates that action and plays a large role in how smoothly the bike shifts. The Mariner D8 with its trigger shifter is the clear winner.
The trigger shifting mechanism found on the Mariner D8 is made up of two triggers that are used to shift the bike’s gears—one operated with the thumb, one operated by the forefinger. Pressing the thumb trigger puts the bike into a higher gear, meaning it will be harder to pedal and make the bike go faster. Pulling the finger trigger puts the bike into a lower gear which makes it easier to pedal up hills.
The Mariner D7, however, uses a twist shifting mechanism which, while functional, is generally harder to use and more prone to failure.
The twist shifter of the Mariner D7 is integrated into the bike’s handlebar grip. Twisting the grip toward you puts the bike into a higher gear while twisting the grip away from you puts the bike into a lower gear.
The problem with twist shifters is that more physical effort is required to engage the derailleurs which can result in extra strain on your wrist. Twist shifters also tend to get sticky or bound up with use over time, making shifting more difficult.
Some riders may prefer twist shifters, but overall, most find trigger shifters easier to use and more reliable—one of the best reasons to choose the Mariner D8 over the Mariner D7.
Downsides But Not Deal Breakers
Overall, the Mariner D7 and D8 have both been well received by users and critics alike. However, both bikes suffer from a few of the same drawbacks you should definitely know about if you’re considering investing in either bike.
The first biggest complaint from users is that when shipped, neither the Mariner D7 or D8 come fully assembled and aren’t ready to ride out of the box. Before you can ride your new Mariner, you must install the pedals, connect the chain to the gears, adjust the tightness of the main hinge, connect the seat post to the frame, and fill the tires with air.
Many buyers recommend having a bike shop assemble the bike, especially if you aren’t comfortable doing it yourself. However, if you have some bike-wrenching experience, total setup time should take anywhere from 20 to 30 minutes.
Another big complaint is that the wheels of the Mariner D7 and D8 may not be “true” upon arrival. If when you spin the wheels you see a wobble or notice the rim of the wheel rubs on the brakes, you’ll need to take the bike to a bike shop to have the wheels straightened out—i. e. “trued.”
Apparently, both the Mariner D7 and D8 are prone to scratches, especially on the seatpost and handlebar post from sliding up and down during folding. This doesn’t affect the rideability or functionality of the bike, so it isn’t a total dealbreaker, just something to be aware of.
The Verdict
If you’re on the fence about whether you should buy the Dahon Mariner D7 or D8, save yourself some headache and go with the updated and newest model—the Dahon Mariner D8. If you have extra room in your budget, that is.
With an aluminum frame for a better feel on the road, an upgraded Shimano Altus rear derailleur, and an easier-to-use trigger shifter, the Dahon Mariner D8 will serve you well on your daily commute. When you get where you’re going, just fold it up and stash it away until you’re ready to ride again.
