K4
K4 Slot Box Windsurfing blanking plates 100mm & 130mm- Yellow
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K4 Shark Slot Box Paddleboard, SUP, Windsurfing Fins
K4 Shark Slot Box Paddleboard, SUP, Windsurfing Fins
K4 fins have created a unique and new material for windsurfing. OptoFlex is a molded resin long fibre matrix that has been carefully manipulated to provide the perfect flex patterns for windsurfing. Our K4 technicians took a long time to create the perfect material with the qualities needed to provide the performance we now appreciate. Lighter, snappier and with outstanding flex memory
Sold as a pair but if you would like a single for £11.25 just ask.Â
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K4 BUBBLE FREESTYLE WINDSURFING FIN POWER BOX
K4 BUBBLE FREESTYLE WINDSURFING FIN POWER BOX
Our Freestyle fin developed by Andy ‘Bubble’ Chambers. We originally had two very different prototypes; one worked great on flat water but would spin out in the chop, the other was rock solid in the chop but too grippy on flatwater. The BUBBLE freestyle fin has the perfect blend of grip to be secure in the chop and into carving manoeuvres, whilst still allowing plenty of release for double spins.
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K4 BUBBLE FREESTYLE WINDSURFING FIN US BOX
K4 BUBBLE FREESTYLE WINDSURFING FIN US BOX
Our Freestyle fin developed by Andy ‘Bubble’ Chambers. We originally had two very different prototypes; one worked great on flat water but would spin out in the chop, the other was rock solid in the chop but too grippy on flatwater. The BUBBLE freestyle fin has the perfect blend of grip to be secure in the chop and into carving manoeuvres, whilst still allowing plenty of release for double spins.
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K4 FCS Surf Assy Side Front Fin Pair
These fins are Asymmetrical.
"We’ve had a unanimous thumbs up for the K4 Fins SUP surf fins; from the Bluesmiths team using them in Maui perfection, to the likes of big wave ripper Finn Mullen in Ireland, through to those in the UK having their first experience of Stand Up Paddling.
We’re excited to bring you a substantial range of sizes in the K4 shop to tune your board for every wave. Our asymmetric front fins are available in 8, 10, 12, 13  and 14cm." - K4 Fins
These K4 surfboard FCS fins are perfect for directional kiteboard surfboards, normal surfboards and wave sups. Buy the 10cm ones for a looser feel or for smaller boards and buy the 12cm for pretty much everything else.
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K4 Fang Freeride Windsurfing Fin Tuttle Box
K4 Fang Freeride Windsurfing Fin Tuttle Box
Developed with help from the Official Test Centre Weymouth. This fin is the culmination of years of R&D with new materials and new fin designs. We made numerous prototype moulds and moulded them in several materials until we found the best combination. We then refined the prototypes to arrive at the Fang Freeride. A fin that will give you amazing speed and control, secure carving and let you fly upwind. The material is K4’s ‘Super Stiff’, the ideal composite for Freeride fins; great reflex, stiff enough for excellent acceleration and direct response, enough flex for speed, grip and control.
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K4 3SW Freeride Freestyle Freewave Windsurfing Power Box Fin
K4 3SW Freestyle Freewave Freeride Windsurfing Power Box FinÂ
The 3SW freestyle-wave fin. Developed with help from the Official Test Centre Weymouth. A fin that will give you amazing speed and control, secure and loose carving on the fast flats or choppy waves. The material is K4’s ‘Super Stiff’, the ideal composite for freestyle-wave fins; great reflex, stiff enough for excellent acceleration and direct response, enough flex for speed, grip and control. The 3SW also works great in big wave boards.
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K4 Flex US Box Rear Fin for SUP, Paddleboard or Windsurf Board
K4 Flexy US Box Rear Fin for SUP / Paddleboard or Windsurf Board
These can be used as 'twinsers' or as a single rear fin. They come complete with nylon plate and screw for US box fin systems.
"Our original fin for performance wave riding. Lots of flex for amazing grip and looseness on the wave. Raked template for control. A progressive foil for different flows between tip and base. Test winner. Will loosen up a 'stiff' board and are particularly sweet as twin fins as they eliminate that unwanted top turn spin out." - K4 Fins
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This product has multiple variants. The options may be chosen on the product page
K4 3SW Freeride Freestyle Freewave Windsurfing US Box Fin
K4 3SW Freestyle Freewave Freeride Windsurfing US Box FinÂ
The 3SW freestyle-wave fin. Developed with help from the Official Test Centre Weymouth. A fin that will give you amazing speed and control, secure and loose carving on the fast flats or choppy waves. The material is K4’s ‘Super Stiff’, the ideal composite for freestyle-wave fins; great reflex, stiff enough for excellent acceleration and direct response, enough flex for speed, grip and control. The 3SW also works great in big wave boards.
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This product has multiple variants. The options may be chosen on the product page
K4 Fang Freeride Windsurfing Fin Power Box
K4 Fang Freeride Windsurfing Fin Power Box
Developed with help from the Official Test Centre Weymouth. This fin is the culmination of years of R&D with new materials and new fin designs. We made numerous prototype moulds and moulded them in several materials until we found the best combination. We then refined the prototypes to arrive at the Fang Freeride. A fin that will give you amazing speed and control, secure carving and let you fly upwind. The material is K4’s ‘Super Stiff’, the ideal composite for Freeride fins; great reflex, stiff enough for excellent acceleration and direct response, enough flex for speed, grip and control.
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This product has multiple variants. The options may be chosen on the product page
K4 Race Paddleboard SUP Fin US Box 21cm and 24cm
Swept back SUP race fin.
45 degree rake so you don’t have to worry about weed or debris.
Foil optimised for paddling speeds, but taking many pointers from our speed windsurfing fins. In fact I stuck this yellow fin in my windsurf and did 48mph on it!
Dynamic Flex material gives more grip, better tracking and more speed than stiffer materials.
An already proven SUP race fin can also be used on windsurfers with US box as a weed fin.
Available in a choice of two sizes:
- 24cm – 255 area – 260g
- 21cm – 210 area – 215g
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K4 FCS Thruster Fin Set for Surfboard Paddleboard SUP
"We’ve had a unanimous thumbs up for the K4 Fins SUP surf fins; from the Bluesmiths team using them in Maui perfection, to the likes of big wave ripper Finn Mullen in Ireland, through to those in the UK having their first experience of Stand Up Paddling.
We’re excited to bring you a substantial range of sizes in the K4 shop to tune your board for every wave. Our asymmetric front fins are available in 8, 10, 12, 13  and 14cm." - K4 Fins
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This product has multiple variants. The options may be chosen on the product page
K4 Shark 2 Mini Tuttle Paddleboard,SUP, Windsurf Fins
K4 Shark Mini Tuttle Paddleboard,SUP, Windsurf Fins
K4 fins have created a unique and new material for windsurfing. OptoFlex is a molded resin long fibre matrix that has been carefully manipulated to provide the perfect flex patterns for windsurfing. Our K4 technicians took a long time to create the perfect material with the qualities needed to provide the performance we now appreciate. Lighter, snappier and with outstanding flex memory.
Sold as singles. If you want a pair, please buy 2.
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This product has multiple variants. The options may be chosen on the product page