Durability is one of the goals set by FFWD from the get-go. Therefore FFWD demand more of their rims than they would if they had lower spoke tensions in our wheels. FFWD rims have reinforced strips where the spoke holes are placed, to ensure that high tensions are not an issue. Regular Modulus lay-up; only local fibers control the spoke force. FFWD engineers can put the right fibers at the right place. The spoke force is spread out through the reinforced strip and distributes the stresses over a larger part of the rim. FFWD use a clear coat on rims (except for the Discs) is also done with the focus on durability. It adds a little bit of weight (20g for a F5 rim), but FFWD designers are pretty proud of decals, therefore want to keep them on the rim as long as possible. If the decals are not protected by the clear coat, they would very likely get damaged by cleaning, weather, etc.

Why FFWD uses 24 spokes for Rear wheel? The front wheel only has lateral (direction of axle) and radial/frontal (perpendicular to the axle) forces to handle. The rear wheel however also has to deal with the rider power transfer. This creates higher forces in the trailing spokes, because only the trailing spokes can transfer the power of the rider to the rim. The leading spokes will slacken when there is a momentum.

For Example when a rider is on a hill and pushes the pedal with a force equal to 150kg. When the gearing is on its lowest (for instance 39x27), the momentum in the hub is the highest. The initial load in our spokes is 110/120kgF in the rear and 90/100kgF in the front. The extra load (due to the drive momentum) that the rider puts on these spokes will be: 150 x (175/78) x (55/23) = 800kgF. This force has to be spread out over all trailing spokes. Less spokes means there will be higher peak forces in the rear wheel.

24 spokes -> 120+ (800/12) = 187kg peak

20 spokes -> 120+ (800/10) = 200kg peak

That could be a reason why other manufacturers sometimes use a lower initial load on their spokes when using 18h or 20h. To keep the peak forces under control. This lower initial load, however, will decrease the lateral stiffness of the wheel (in other words: less force is needed to displace the rim sideways, it is not a good thing).

FFWD decided to put in an extra 20g, but in exchange FFWD can build wheels with a higher durability, stiffness and more responsiveness. Those who feel that they need more rigidity than a standard 20/24h lacing. FFWD F6R/F9R Carbon Tubular Wheels Spesifications:

• FFWD F6R Carbon Tubular Front and F9R Tubular Rear Wheels with DT Swiss 240s hubs

• Superstiff High Tensile TC35 Carbon

• Rim 60mm deep front and 90mm FFWD DARC Profile

• FFWD decals under clear coat

• New Neutral decal optional

• DT Swiss 240s hubs

• DT Aerolite spokes 20/24H aero blade (0.9 x 2.3mm); DT Pro Lock Brass nipples.

• Hand made at Netherlands

• Comes with exclusive wheel bags, quick release set, valve extensions and brake pads.

• Weight Front 590g and rear 920g ( 1620g wheelset)

• FFWD DARC profile employs a negative arc section which will compress the air, thus increasing the pressure, similar to the way the air pressure works on the topside of an aerofoil.