Mountain Buggy Duet V4 review: a side-by-side double buggy as narrow as a single

Our verdict

For Jonny and his partner Claire, the Mountain Buggy Duet V4 delivers on its main promise: a side-by-side double buggy that’s compact enough for everyday family life. At just 63cm wide, it has around the same wheelbase width as many single buggies.

Built for practicality, the Duet has large air-filled tyres that handled pavements, hills, park paths and gravel well. Compared with the much smaller Stokke Yoyo the family uses with their three-year-old, it felt far more capable on uneven ground. “There is nothing that’s stopping this,” he says. “It’s just going to plough through whatever terrain.”

There are a few niggles to consider. Assembly took up to an hour, a clicking sound developed around the brake during testing, and transporting the frame and two non-folding carrycots by car proved tricky.

Even so, the Duet gets the fundamentals right. “The width is brilliant,” Jonny says. Its generous storage basket, supportive carrycots and adjustable handlebar also helped make everyday trips with newborn twins more manageable, while its narrow wheelbase allowed the family to use it in places where some side-by-side buggies would struggle.

The large rain cover protects both carrycots, while the family added extra shade protection in brighter weather.

How we tested the Mountain Buggy Duet V4

Parent tester and Mumsnet HQer Jonny tested the Mountain Buggy Duet V4 for seven weeks (and counting!) with his newborn twins.

He and his partner Claire used the buggy daily on pavements, park paths, gravel and uneven ground. They also took it into shops and cafés and used it on the bus.

The twins remained in the carrycots throughout testing, but Jonny’s test package also included separate pushchair seats for use after the carrycot stage. Jonny fitted these to the frame before the twins were born but has not yet used them day to day. He also tested two Mountain Buggy nest™ i-Size car seats with adapters for car journeys, including a trip to the hospital.

What’s in the box?

Jonny’s test package included:

• Mountain Buggy Duet V4 frame

• Two pushchair seats

• Two carrycots

• Two Mountain Buggy nest™ i-Size car seats each with a rotating base

• Car seat adapters

• Two bumper bars

• Sun hoods

• One large rain cover

• Bottle holder

• Instruction booklet

How easy is the Mountain Buggy Duet V4 to assemble?

Jonny spent around an hour assembling the Duet. The instructions weren’t especially clear, and the setup video he found featured an older model, which made some steps harder to follow. Attaching the carrycot hoods also took a little patience. Once Jonny understood where each part went, repeating the process was much quicker.

The Duet’s four 10-inch air-filled tyres handled kerbs, gravel and uneven park paths with ease.

How does the Mountain Buggy Duet V4 look?

As part of Mountain Buggy’s Heritage Collection, the Duet comes in five colourways – Caviar, Matcha, Mustang, Ocean and Solare – all with herringbone fabrics and vegan leather accents. Jonny tested the predominantly black Caviar version. Its seat fabrics don’t feel quite as plush as those on his regular Stokke Yoyo, but they stood up well to everyday use.

"The Duet isn't fancy, but it’s durable and sturdy,” he says. For a buggy carrying twins day after day, that durability may matter more than a luxurious finish.

The aluminium frame feels strong, while the adjustable vegan leather handlebar feels solid and comfortable. At 6ft, Jonny could set it high enough to push without hunching over, making it noticeably more comfortable for him than the lower handlebar on the Yoyo.

The handlebar-mounted active brake and red go/stop lever are easy to operate without relying on a foot pedal.

How safe and sturdy is the Mountain Buggy Duet V4?

The Duet remained stable across pavements, hills and uneven park paths. Its sturdy frame, rear-wheel suspension and large tyres kept it steady, even over rougher ground. “The buggy feels very safe and doesn’t rock like other buggies we’ve used,” Jonny says.

Jonny operated the brake using a red go/stop lever mounted on the handlebar. He found it easy to use and liked being able to secure the buggy without relying on a stiff foot pedal – particularly when wearing open-toe shoes.

Although the twins hadn’t yet moved into the main seats, Jonny fitted them to the frame and found their five-point safety harnesses simple to fasten.

A clicking noise developed around the brake mechanism during testing. Mountain Buggy sent Jonny a video explaining how to adjust a bolt, but the noise remained noticeable during everyday use.

The two UPF50+ carrycot hoods provide useful shade, although Jonny would have liked them to extend a little further.

How comfortable is the Mountain Buggy Duet V4?

During testing, the twins travelled in the two carrycots. Jonny found the mattresses supportive and the carrycots easy to attach and remove. He also liked their raised position and enclosed design. “The twins feel secure because they are surrounded in their bassinets,” he says.

The side-by-side layout also made it straightforward to reach either baby without disturbing the other. Lifting the babies out with the hoods raised took a little practice, but folding each hood back first made it much easier.

The UPF50+ sun hoods provided useful shade, although Jonny would have liked them to extend a little further in bright weather. The family sometimes added a SnoozeShade for extra coverage. The hoods very occasionally slipped out of their fittings, but were straightforward to reattach.

One thing to consider is that the carrycots may feel narrow for larger babies. Mountain Buggy says the Carrycot Plus for Duet is suitable in carrycot mode from birth to around six months, but Jonny felt his twins were already filling their individual carrycots before they were two months old. Age ranges are only a guide, so larger babies may need to move into the main pushchair seats sooner.

The Carrycot Plus offers more flexibility than a standard carrycot. Alongside its lie-flat mode, it has an inclined newborn position and can later be converted into a parent- or forward-facing toddler seat. This provides an alternative to the Duet’s standard pushchair seats.

Jonny’s package included the Duet’s two standard pushchair seats. He fitted them to the frame before the twins were born and found them roomy and sturdy, with individual bumper bars and independently adjustable reclines. As the twins had not yet used them day to day, he wasn’t able to assess their comfort in practice.

Can the Mountain Buggy Duet V4 be used with infant car seats?

Jonny tested the Duet with two Mountain Buggy nest™ i-Size infant car seats and rotating bases. Once he understood how the adapters fitted, he found the seats simple to attach and remove. These car seats can be used in a single or twin travel-system setup with the appropriate adapters.

Adding both car seats made the buggy feel wider and more top-heavy, so Jonny preferred using the carrycots for everyday walks.

The wider setup also affected how the family parked. They sometimes needed to drive forwards into a space to leave enough room on either side to remove both car seats.

Parents hoping to use the Duet regularly as a travel system should check that their chosen car seats and adapters are compatible and consider how much room the full setup will need.

At just 63cm wide, the Duet fitted through Jonny’s standard front door without needing to be folded.

What is the Mountain Buggy Duet V4 like to use day to day?

For Jonny’s family, the Duet’s compact width made the biggest practical difference. It fitted through their standard front door, so they could load the twins into the carrycots indoors and wheel them straight outside. "We can get in and out of the front door without collapsing the buggy,” Jonny says.

Out and about, the Duet was manageable in most shops, cafés and supermarket aisles. The tightest space Jonny encountered was a small Tesco Metro, where he needed to reverse out of the area near the self-checkouts. “Other than that, you don’t really feel like you’re taking up that much space,” he says.

The large air-filled tyres and rear suspension gave a much smoother ride than the family’s Stokke Yoyo on rougher ground. The Duet climbed kerbs easily and handled pavements, park paths and gravel well. Its front wheels have three settings to adapt the handling to different surfaces.

Steering took Jonny a few days to get used to after using his lightweight single buggy, but he soon found it straightforward. As with most double buggies, particularly tight spaces sometimes required a little reversing.

While the air-filled tyres provide a smoother ride, they also bring the possibility of punctures. Jonny was disappointed that the Duet doesn't come with a pump as standard.

The Duet was more manageable on the bus than Jonny expected. It's naturally larger than a single buggy, but its relatively narrow frame made boarding and using the designated buggy space straightforward. “The actual buggy experience on the bus was absolutely fine,” he says.

The family didn't test the Duet on the Tube or take it on a plane. Given its size, it would generally need to travel in the aircraft hold.

The folded Duet takes up most of the boot in the family’s Skoda Kodiaq.

How easy is the Mountain Buggy Duet V4 to fold and store?

Mountain Buggy describes the Duet as having a one-hand standing fold. Jonny found it simple enough once he understood the sequence, but less intuitive than folding a lightweight single buggy.

The carrycots need to be removed first, although the regular pushchair seats can remain attached. To collapse the frame, Jonny lowered the handlebar and aligned the wheels before moving around to the front of the buggy and pressing a small grey button.

Unlike the Yoyo, the whole process can’t be completed from behind the handlebar. “There’s definitely a knack to collapsing it,” Jonny says, although he expects it to become second nature with practice.

The Duet folds to 89 x 63 x 55cm with its wheels attached and feels lighter to lift than its sturdy frame might suggest. It still required most of the available boot space in the family’s Skoda Kodiaq.

The two carrycots don’t fold and wouldn’t fit alongside the frame in the family’s boot. For car journeys, Jonny and Claire left them at home and used the compatible nest™ i-Size car seats on the buggy instead.

Storage at home was much easier. By lowering the handlebar, Jonny could fit the Duet fully assembled into an alcove beneath the stairs. This allowed the family to put the twins into the buggy before leaving home and wheel them back inside if they were still asleep after a walk.

What is the storage basket like?

The 10kg storage basket is large, sturdy and easy to access, with a zip cover to help keep essentials contained and out of sight. It comfortably held the family’s changing bag and the everyday supplies needed for the two newborns.

“There’s really good storage,” Jonny says. With the changing bag left packed underneath, the buggy was ready to go without the family needing to gather everything for each trip.

The attached bottle holder was another useful addition and had enough space for the family’s large water bottle.

The large, zip-covered storage basket comfortably held the family’s changing bag and other essentials for two newborns.

What accessories are included?

Jonny’s test package came with two carrycots, two nest™ i-Size car seats, car seat adapters, two bumper bars, a bottle holder and one large rain cover.

The single-piece rain cover protects both children. Jonny initially found its size and shape confusing, but fitting it was relatively straightforward once she had worked out how it attached.

The bumper bars were another welcome inclusion. Jonny had previously used a Yoyo, where a bumper bar was an additional purchase, so he appreciated having individual bumper bars included.

Standard contents vary between the base pushchair and Mountain Buggy’s different bundles. Other accessories available for the Duet V4 include a double mesh and blackout sun cover set, individual food trays, footmuffs, a Carrycot Plus stand and a tyre pump for the air-filled tyres. Some accessories, including the food trays and footmuffs, are sold individually, so parents of twins may need to buy two.

Is the Mountain Buggy Duet V4 easy to clean?

The dark fabrics hid everyday marks well and felt durable enough to withstand regular family use. Jonny found the buggy easy to keep clean, with most fabric components removable and machine-washable.

The buggy remained in good condition throughout the seven-week test, although it wasn’t subjected to any major spills or repeated washing.

Is the Mountain Buggy Duet V4 good value for money?

At £699 for the base buggy, the Mountain Buggy Duet V4 is a significant purchase. The price rises further if you need two carrycots, infant car seats and the relevant adapters.

Still, Jonny felt it represented good value for a side-by-side double buggy. “Double buggies are expensive, but some are astronomical compared to this one,” he says. The cheaper models the family considered didn't feel as sturdy.

The Duet’s value lies in how well it adapts to real family life. Suitable from birth, with seats that last into the toddler years, it combines the capacity of a double buggy with a width that works for everyday shops, doorways and public transport. For Jonny’s family, that day-to-day practicality comfortably outweighed its bulky fold.

About the author

Laura Westerman is Mumsnet’s Deputy Head of Editorial Content and has more than 10 years’ experience as a full-time editor. Eight of those years have been spent writing, commissioning and editing product reviews and round-ups, with a particular focus on buggies and car seats.

Mum to a four-year-old, Laura understands how much the practical details matter when choosing products for family life. She is committed to producing honest, useful reviews and finding reliable options for a range of budgets.

In addition to her work as a writer and editor, she has also appeared in a number of product review videos for Mumsnet's YouTube channel.