Foil Drive Buying Guide: MAX+, Fusion, MAX or Slim?

The right Foil Drive is the system that gives you enough assistance without adding power, battery weight or complexity you do not actually need.

For most riders buying new, the first comparison is now between Foil Drive Assist MAX+ and Foil Drive Fusion. MAX+ is the Gen 2.5 all-rounder. Fusion steps things up for heavier riders, longer powered use and anyone who wants access to the larger 864Wh battery.

Foil Drive Assist Slim remains a different proposition. It is about preserving a light, responsive foil feel for riders who mainly need short bursts of assistance. The original Assist MAX remains highly relevant too, particularly if you already own one, have invested in its batteries or are looking at a used package.

At The SUP Company we look at the whole setup: rider weight, experience, board, foil, conditions, battery, motor position and what you actually expect the motor to do.

This guide works through those decisions in order so you can browse the Foil Drive range at The SUP Company with a clearer idea of what genuinely suits your riding.

The quick answer: which Foil Drive should you choose?

Choose MAX+ if: you want a powerful all-round foil assist for surf, wing, wake, downwind and flatwater use without automatically moving to the larger Fusion platform.
Choose Fusion if: maximum power, heavier-rider performance, longer powered use or the 864Wh Fusion battery are important.
Choose Assist Slim if: you already foil confidently and your priority is minimum weight, pumping, glide and a more natural foil feel after the motor switches off.
Keep or buy an original MAX if: the Gen 2 system already meets your needs, you own compatible batteries, or a well-specified existing package represents better value than moving platforms.

First ask: what do you want the motor to do?

This is more important than choosing a model from a specification table.

A Foil Drive can perform very different jobs.

Help accelerate a surf foil onto a wave.
Assist a flatwater take-off.
Get a wing foiler moving in marginal wind.
Recover quickly after a touchdown.
Motor upwind before a downwind run.
Help practise pumping without repeated tow starts.
Provide longer powered sections.
In the case of Fusion, move much further towards e-foil-style riding.

A rider who uses the motor for ten seconds and then pumps or surfs with it switched off has completely different requirements from somebody who expects propulsion for much of the session.

More battery and more power are useful only if your riding actually uses them.

Foil Drive range comparison

System	MAX+	Fusion	Assist Slim	Original MAX
Generation	Gen 2.5	Gen 2.5	Gen 2	Gen 2
Nominal voltage	43.2V	43.2V	28V / 40V depending on battery	40V
Maximum quoted thrust	35.5kg	37.5kg	26.5kg	29kg
Peak power	2,150W	2,370W	1,854W	1,854W
Sustained power	1,750W	1,850W	1,455W	1,455W
Battery capacity	648Wh at launch	648–864Wh	166–241Wh	332–594Wh
Minimum quoted installed weight	6.71kg	7.13kg with FM+ 650	Approx. 3.75kg	Approx. 4.8kg
Main strength	All-round Gen 2.5 foil assistance	Maximum power and battery range	Low weight and natural foil feel	Proven, versatile Gen 2 platform
Start here if...	You want one versatile new foil-assist system	You need more power, capacity or sustained use	You already foil well and want subtle assistance	You already own Gen 2 equipment or are considering a used system

Installed weights depend on battery and motor configuration, so do not compare one system with its smallest battery against another using its largest.

Foil Drive Assist MAX+: the all-round starting point

The Foil Drive Assist MAX+ is where we would start for many riders buying a new Foil Drive primarily as a foil assist.

It uses Foil Drive's newer Gen 2.5 43.2V platform and launches with the FM+ 650 battery.

Foil Drive quotes:

35.5kg maximum thrust.
2,150W peak power.
1,750W sustained power.
648Wh battery capacity.
6.71kg minimum installed weight in its stated integrated High Power motor and three-blade configuration.
540mm installed length with FM+ 650.

That gives MAX+ considerably more capability than the original MAX while still keeping the electronics housing more compact than Fusion.

Choose MAX+ if...

You want Foil Drive mainly as an assist rather than a full-time propulsion system.
You mix surf, wing, wake, flatwater and downwind riding.
You want strong flatwater-start assistance.
You want more power than original MAX but do not need the Fusion 860 battery.
You value a shorter system over maximum battery capacity.
You want to enter the newer FM+ battery ecosystem.

Foil Drive's September 2026 material positions MAX+ for a broad range of abilities below 100kg using small to mid-length boards. That should be treated as useful guidance rather than an absolute cut-off.

A 95kg beginner on a small inefficient board may make greater demands on the system than a heavier experienced rider using an efficient mid-length board and suitable foil.

Foil Drive Fusion: when you want more system

Foil Drive Fusion is the more power- and runtime-focused Gen 2.5 system.

Foil Drive quotes:

37.5kg maximum thrust.
2,370W peak power.
1,850W sustained power.
648–864Wh battery capacity.
7.13kg minimum installed weight with FM+ 650.
8.08kg minimum installed weight with Fusion 860.

Compared with MAX+, that is not an enormous jump when both systems use the same FM+ 650 battery. Fusion adds about 2kg of maximum quoted thrust, 220W peak power and 100W sustained power.

The more significant difference is what the larger Fusion chassis allows.

The 864Wh Fusion 860 battery

Fusion can use its dedicated 864Wh battery, giving around a third more stored energy than the 648Wh FM+ 650.

This is particularly relevant if you expect repeated powered starts, longer motoring sections or e-foil-style riding.

Fusion can also use FM+ 650

The interesting part of Gen 2.5 is that Fusion does not have to carry the largest battery every day.

The FM+ 650 works in Fusion using the FM+ Battery Adaptor.

With FM+ 650 fitted, Fusion is quoted at 7.13kg versus 6.71kg for MAX+. That is only around 420g difference.

Fusion is still physically longer, though: approximately 658mm installed versus 540mm for MAX+ with the same battery family.

Choose Fusion if...

You are a heavier rider and regularly need substantial thrust.
You expect longer powered sections.
You want an e-foil alternative as well as foil assistance.
You want the option of an 864Wh battery.
You are learning and expect repeated powered recoveries and restarts.
You want maximum system headroom for future boards and foils.

Foil Drive specifically includes riders above 100kg within its Fusion positioning, making it the system we would examine particularly closely as rider weight and motor reliance increase.

MAX+ or Fusion?

This is now the main new-system buying decision.

Your priority	Start with
General surf foil assistance	MAX+
Light-wind wing assistance	MAX+
Mixed surf / wing / wake / flatwater	MAX+
Smaller physical system	MAX+
Rider around or above 100kg	Compare Fusion closely
Very demanding flatwater starts	MAX+ or Fusion depending on rider and equipment
Maximum battery capacity	Fusion
Long powered sections	Fusion
E-foil-style riding	Fusion

If you are choosing between these two systems specifically, the key question is not whether Fusion is technically more powerful. It is.

The question is whether your riding benefits enough from that extra capability to justify the additional size and potential battery weight.

Foil Drive Assist Slim: when weight matters more than runtime

Assist Slim is not simply a cheaper or smaller version of MAX.

It has a different purpose.

Foil Drive designed Slim around riders who already foil efficiently and want enough motor assistance to get moving without carrying unnecessary battery once flying.

Its current headline specifications include:

Up to 26.5kg quoted thrust.
1,854W peak output.
1,455W sustained output.
166–241Wh battery range.
Minimum installed weight around 3.75kg with Slim Performance.

Choose Assist Slim if...

You are already a capable foiler.
You mainly want assisted pop-ups or take-offs.
Pumping efficiency matters.
You want minimum weight while surfing and carving.
You are happy with a smaller battery because the motor spends much of the session switched off.
You prioritise natural foil feel over maximum powered runtime.

Do not choose Slim just because you want the lightest system

If you are learning, repeatedly restarting or need significant motor assistance just to get the board moving, removing battery and system weight may solve the wrong problem.

The lighter setup only makes sense when its level of assistance matches your ability and equipment.

You can explore current options through the Foil Drive kits collection.

A note on Slim batteries

Slim has another important complication: its batteries do not all operate at the same voltage.

Slim Performance: approximately 166Wh, 40V platform.
Slim Endurance: approximately 241Wh, 28V platform.
Slim Travel: approximately 178Wh, 40V travel-oriented configuration.

The Slim Endurance battery requires its correct 28V charger. Do not assume all Slim batteries and chargers are interchangeable simply because they fit the same core system.

Original Assist MAX: still very relevant

The arrival of MAX+ does not suddenly make the original Foil Drive Assist MAX Gen 2 a poor system.

Foil Drive quotes up to 29kg thrust, 1,854W peak power and 1,455W sustained power, with batteries ranging from approximately 332Wh to 594Wh.

The lightest configuration starts around 4.8kg with MAX Sport.

That means the original MAX still has some advantages for existing owners, particularly those who have deliberately built a lightweight system around its smaller batteries.

Keep your original MAX if...

It gets you onto foil reliably.
Your batteries cover your normal sessions.
You already own several healthy Gen 2 batteries.
You value a lightweight MAX Sport configuration.
Your actual problem can be solved with a battery, motor or foil change rather than a complete new system.

Move from MAX to MAX+ if...

You genuinely need more thrust and sustained power.
You are already replacing a large part of your system.
You want the newer FM+ battery platform.
You expect to add Fusion later and value shared FM+ battery compatibility.

Remember that original MAX batteries and chargers do not move across to MAX+. The cost of switching platforms therefore needs to include more than the electronics unit.

Battery compatibility comes before battery capacity

Battery family	Original MAX	MAX+	Fusion	Slim
Original MAX batteries	Yes	No	No	No
FM+ 650	No	Direct fit	Yes, with adaptor	No
Fusion 860	No	No	Yes	No
Slim batteries	No	No	No	Correct Slim battery only

The FM+ 650 has a rated capacity of 648Wh. It fits MAX+ directly and fits Fusion with the correct adaptor.

The FM+ adaptor does not convert an FM+ battery for use with original MAX. It simply provides the correct physical fit inside Fusion's longer battery housing.

Foil Drive has also indicated a smaller FM+ 430 for early 2027. Until the final specification and availability are confirmed, base a current purchase on batteries you can actually obtain.

Universal retrofit motor or integrated mast?

Once you have chosen the electronics and battery, the next decision is how the motor attaches to the foil.

Universal retrofit system

A retrofit Foil Drive motor uses a pod mounted to a compatible existing foil mast, with the motor cable running externally.

This is usually the more flexible route.

Choose retrofit if:

You want to keep your existing mast.
You use more than one foil system.
You want to move Foil Drive between different setups.
You want flexibility over motor height.
You are still learning which motor position suits you.

The compromises are the external cable and pod, which create more drag than a purpose-built integrated setup.

Integrated Foil Drive mast

An integrated mast incorporates the Foil Drive installation into a purpose-designed mast, reducing external hardware and cable drag.

Choose integrated if:

You use Foil Drive regularly.
You want the cleanest possible installation.
You prioritise pumping, glide and free-foiling performance.
You are happy to dedicate a mast to Foil Drive.
You already know the motor position you want.

The important trade-off is flexibility. Integrated systems are designed around particular foil brands and motor positions, so check the exact mast, system generation and Fusion/MAX+ compatibility before ordering.

An integrated mast improves efficiency and reduces drag. It does not make the motor itself more powerful.

Standard V2 or High Power V2 motor?

Motor choice is another area where the highest specification is not automatically right for everybody.

Standard V2

The Standard V2 is the lighter motor option and remains well suited to riders who do not require maximum low-speed torque.

It is a useful choice where low weight and sufficient rather than maximum take-off power are the priorities.

High Power V2

The High Power V2 places more emphasis on low-end thrust and efficiency.

That makes it particularly interesting for:

Heavier riders.
Smaller boards.
Smaller or faster foils.
Difficult flatwater starts.
Riders prioritising acceleration over maximum top-end speed.

Foil Drive states that the High Power V2 adds around 130g compared with Standard V2 while providing more low-end torque and improved efficiency.

That is a relatively small weight difference in the context of a complete Foil Drive setup, so we would normally choose the motor around the actual load it needs to move.

Two blade or three blade?

Propeller choice changes how the power is delivered.

In simple terms:

Two blade: more emphasis on top-end speed and reduced low-speed load.
Three blade: more low-end grip and take-off torque, particularly useful for heavier riders and demanding starts.

The three-blade option therefore makes particular sense when the main challenge is getting the board moving and onto foil rather than achieving maximum powered speed.

For more detail, see our Foil Drive propeller guide.

How high should the motor be on the mast?

Motor height changes both how long you can remain under power and how much drag you feel once foiling.

A motor mounted relatively high on the mast can lift clear of the water once the board rises, which is ideal when Foil Drive's job is mainly getting you onto foil.

A lower motor remains engaged for longer and becomes more useful when you want continued powered assistance.

Dedicated e-foil-style setups position the motor much lower again, closer to the foil, so that propulsion remains available continuously.

There is no universal perfect height. Board length, mast length, sea state, intended discipline and how long you want the motor engaged all affect the decision.

Do not undersize the board because you have a motor

Foil Drive makes many boards easier to get moving, but it does not remove the laws of balance, displacement and foil take-off.

A beginner should not automatically buy a very small sinker because the system has enough quoted thrust.

An efficient mid-length board can make the entire Foil Drive experience easier:

Earlier acceleration.
Less energy used getting onto foil.
Easier touchdowns and restarts.
Less demand on the battery.
More relaxed learning.

Likewise, an appropriate front wing is often more important than another few kilograms of motor thrust.

A larger, lower-speed foil can release earlier and make progression easier. A small high-performance foil may require substantially more speed and technique before it flies.

Foil Drive recommendations by rider and use

Rider / use	Where we would start	Why
New Foil Drive buyer, mixed use	MAX+	Strong all-round Gen 2.5 balance
Surf foiler wanting more waves	MAX+	Plenty of take-off assistance without automatically choosing Fusion
Experienced surf foiler prioritising low weight	Slim or lightweight MAX configuration	Less battery and installed weight once the motor is off
Wing foiler wanting marginal-wind help	MAX+	Strong acceleration with broad use beyond winging
Flatwater pumping practice	MAX+	Powerful starts without requiring maximum Fusion capacity for everyone
Heavier rider	Compare Fusion	More power headroom and larger battery option
Rider above roughly 100kg	Fusion conversation first	Specifically within Foil Drive's intended Fusion use
Long powered sessions	Fusion	864Wh battery option and highest current system output
E-foil-style riding	Fusion	Designed to bridge foil assist and powered foiling
Pumping / natural foil feel	Slim	Lowest installed weight and assist-focused use
Existing MAX owner	Assess current setup first	A battery or motor change may be more useful than replacing everything
Existing Fusion owner wanting less weight	FM+ 650 + adaptor	Reduces battery weight without replacing the Fusion system

What about beginners?

There is no single “beginner Foil Drive”.

A learner's experience depends on much more than rider weight.

We would want to know:

Your previous foiling experience.
Your weight.
Your board volume and length.
Your front-wing area and design.
Whether you want to surf, wing, flatwater foil or e-foil.
Where you expect to learn.
Whether the motor is primarily for take-off or sustained riding.

For some beginners MAX+ provides plenty of assistance. Fusion becomes more relevant as rider weight, battery requirement and time spent under power increase.

Slim is generally more suited to riders who already understand how to foil and want electrical assistance without significantly changing the free-foiling feel.

How much runtime do you actually need?

Runtime claims need context.

A rider who surfs for an hour but runs the motor for six minutes has not had six minutes of “session time”. They have had an hour-long session with six minutes of electrical assistance.

Another rider continuously powering around for thirty minutes may consume far more energy despite being on the water for half as long.

Battery Wh is useful for comparing stored energy, but real consumption depends on:

Rider weight.
Board efficiency.
Foil size.
Motor and propeller.
Motor height.
Wind and current.
Number of starts and touchdowns.
Throttle use.
How much time you spend free-foiling.

When somebody gives you a Foil Drive runtime figure, ask how it was measured.

What should a complete Foil Drive quote include?

A useful quote should make it obvious what you are actually buying.

Foil Drive electronics unit.
Compatible battery.
Correct charger and UK lead.
V3 Controller where supplied.
Standard or High Power motor.
Correct motor cable length.
Universal pod or integrated mast arrangement.
Chosen propeller setup.
Required mounting hardware.
FM+ Battery Adaptor where needed for Fusion.
Compatible mast and foil if these form part of the package.

Do not assume that an “integrated motor” package necessarily includes the mast itself. Check the exact listing and package contents.

Try Foil Drive at The SUP Co x Lymington

Foil Drive is exactly the sort of product where specialist advice and testing can save an expensive mistake.

Through Try It Now at The SUP Co x Lymington, we can help with Foil Drive, foil-assist and technical foil setup questions and offer selected demo opportunities where conditions, equipment and rider suitability allow.

If you already own a foil setup, bring or send us the exact board, mast, fuselage and front-wing details. Photographs are useful if you are unsure which generation of motor, connector or mast you have.

Please contact us before travelling if there is a particular Foil Drive system you want to see or try so we can confirm current demo availability.

Finance and delivery

Finance options are available on qualifying orders, which can be useful when investing in a complete setup.

Foil Drive packages can vary by electronics unit, battery, motor, mast, propeller and mounting arrangement. Availability can therefore differ between configurations.

If timing matters, ask us to confirm the actual parts required and expected delivery before ordering.

More Foil Drive buying advice

If you are still deciding whether foil assist is the right route at all, read our Foil Assist vs eFoil vs Parawing guide.

For propeller choices, see the Foil Drive propeller guide.

You can also browse the complete Foil Drive collection for current systems, batteries and accessories.

Foil Drive buying FAQs

Which Foil Drive should most new buyers start with?

For somebody primarily wanting foil assistance across surf, wing, wake, downwind and flatwater riding, MAX+ is the logical starting point in the current Gen 2.5 range. Fusion becomes more relevant when rider weight, sustained power or battery capacity requirements increase.

What is the difference between MAX+ and Fusion?

Both use Foil Drive's Gen 2.5 43.2V platform and both can use FM+ 650. MAX+ is shorter and lighter on the same battery, while Fusion provides slightly more power and can also use the much larger 864Wh Fusion battery.

Which Foil Drive is better for riders over 100kg?

Fusion deserves particularly close consideration. Foil Drive specifically includes riders above 100kg within its Fusion positioning. Board efficiency, foil size, rider experience and intended motor use still matter, so weight should not be the only decision.

Which Foil Drive is lightest?

Assist Slim is the lightweight performance system, with a quoted minimum installed weight around 3.75kg using Slim Performance. It suits capable riders who want short periods of assistance while preserving pumping, glide and free-foiling feel.

Is Slim best for beginners because it is lighter?

Not usually for that reason alone. Slim places more emphasis on short bursts of assistance and efficient free-foiling. A learner requiring repeated starts and substantial motor reliance may be better served by MAX+ or Fusion alongside a suitable board and foil.

Can MAX+ use my original MAX batteries?

No. Original MAX uses the Gen 2 40V battery platform. MAX+ uses the newer Gen 2.5 FM+ battery system and compatible 43V charging equipment.

Can MAX+ and Fusion share batteries?

They can share the FM+ 650. It fits MAX+ directly and requires the FM+ Battery Adaptor in Fusion. The Fusion 860 battery is specific to Fusion.

Can I use my existing foil mast?

Often, yes, using the correct universal retrofit pod, adaptor and motor cable. Compatibility still needs checking for the exact mast. An integrated mast is an alternative if you want a cleaner, lower-drag dedicated Foil Drive installation.

Is an integrated mast more powerful?

No. Its main advantage is reduced drag and a cleaner installation. That can improve efficiency and ride feel, but it does not increase the motor's electrical output.

Should I choose Standard or High Power motor?

Standard V2 is the lighter option. High Power V2 provides more low-end torque and improved efficiency, making it particularly relevant for heavier riders, smaller boards and foils, and demanding take-offs.

Should I choose two or three propeller blades?

A two-blade setup puts more emphasis on top-end speed. Three blades provide more low-speed grip and take-off torque, making them particularly useful for heavier riders and difficult starts.

Does Foil Drive mean I can use a much smaller board?

Foil Drive can help a smaller board accelerate, but it does not remove the balance and efficiency benefits of suitable volume and length. Particularly for learners, an efficient mid-length board can make take-offs, touchdowns and battery use considerably easier.

Does Foil Drive replace an eFoil?

Not every Foil Drive setup is intended to. MAX+, MAX and Slim are primarily foil-assist systems. Fusion can be configured much further towards continuous powered riding and is the Foil Drive system to examine if an e-foil alternative is part of your goal.

Can I try Foil Drive before buying?

Ask The SUP Co x Lymington about current foil-assist demo opportunities. Availability depends on equipment, conditions and rider suitability, so contact us before travelling with details of your current setup and what you want to achieve.

Can The SUP Company recommend a complete setup?

Yes. Send us your rider weight, experience, board, current foil, preferred discipline and budget. We can work through the system, battery, motor, mounting arrangement and any additional parts required.

Choose your Foil Drive around your riding

There is no reason to carry an 864Wh battery if your motor only runs for a few seconds between waves. Equally, there is little point choosing the lightest system if it repeatedly leaves you without enough assistance to get onto foil.

For most new all-round foil-assist buyers, start with MAX+.

Move towards Fusion as rider weight, sustained motor use and battery requirement increase.

Look at Slim when you already foil well and minimum weight matters more than runtime.

Keep an original MAX when it already does the job or can be improved without changing the whole platform.

Then match the battery, motor, mast position, board and foil to the same goal.

Contact The SUP Company for a complete Foil Drive recommendation, visit The SUP Co x Lymington or browse the Foil Drive collection.

Foil Drive Buying Guide: MAX+, Fusion, Slim and MAX Explained