Foil Drive Assist, Fusion or MAX+: which setup fits your riding?
“Assist” is a family name, not one specification. Compare the Assist Slim, original Assist MAX, newer Assist MAX+ and Fusion by the battery and motor you will actually order.
Assist Slim: short boosts and performance riding
The Assist Slim favors a low-profile, lighter setup for advanced surf, wing and downwind riders who primarily need help getting on foil. Its smaller batteries mean less runtime; the store does not recommend prolonged motor-assisted riding. Two Slim Performance batteries with the retro-fit High Power Motor Kit are listed at $5,599.40. The Slim Endurance option requires a separately purchased 28V charger.
Original Assist MAX: the existing all-round platform
The Assist MAX offers High Power, Sport and Travel battery options. A MAX Sport Battery with Standard v2 Motor Complete is $5,161.20; a MAX High Power Battery with High Power v2 Motor Complete is $6,261.75. Compare complete configurations rather than confusing a replacement base unit with a ready-to-ride kit.
Assist MAX+: newer 43V all-rounder
The Assist MAX+ replaces the original MAX in the newer lineup. Its listed specifications include 43.2V, a 648Wh FM+ 650 battery, 35.5kg maximum thrust and 2,150W peak boost power. Minimum listed installation weight is 6.71kg with the specified integrated-motor configuration; retro-fit hardware adds weight. The FM+ 650 with retro-fit High Power Motor Kit is $6,699. The included charger is the 43V 12amp model.
Important: existing 40V Assist MAX batteries and chargers are not compatible with MAX+. It accepts the FM+ battery range. Do not select “No Battery” unless you already have a compatible battery.
Fusion: prioritize power and runtime
The Fusion pairs 43V electronics with a removable Fusion 860 battery rated at 864Wh. It is aimed at riders seeking longer powered rides or an adaptable efoil alternative. With the Fusion 860 battery and retro-fit High Power Motor Kit, the listed price is $8,199. An FM+ 650 configuration with the same motor kit is $7,699; FM+ batteries require the appropriate Fusion adaptor.
Which would we start with?
- Short boosts and performance-first riding: discuss Slim.
- Replacing or extending an existing MAX setup: check original MAX compatibility first.
- A new all-round assist system: compare MAX+ configurations.
- Maximum runtime and powered versatility: discuss Fusion. The MAX+ listing specifically points riders 90kg and above seeking maximum power and runtime toward Fusion.
Battery energy is not a runtime guarantee: rider weight, foil, throttle and conditions change consumption. Check mast fit, cable length, motor choice and board signal compatibility before ordering. Carbon-track boards may need an external antenna.
Call The Foil Shop at (909) 326-0732 for a matched configuration. Prices checked November 7, 2026; current product-page prices apply. “No Motor” and “No Battery” configurations are not complete setups.