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's power transfer [1]. 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 [2].
Let's say a rider is on a hill and pushes the pedal with a force equal to 150kg [3]. 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*(175/78)*(55/23) = 800kgF [4]. 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 -> not a good thing).
So, therefore FFWD decided to put in an extra 20g, but in exchange we can build wheels with a higher durability, stiffness and more responsiveness. For those who feel that they need more rigidity than our standard 20/24h lacing (cyclocross for instance), we propose the ControlTM version with 24/28h lacing. ControlTM is available on most models.
We actually use multiple layers of different types of carbon. Only the outer layer is made from a 3K weave. Underneath this layer are layers of UDF (Uni-Directional Fiber) sheets. A mixture of different angles to resemble a uniform material. Because carbon fiber can handle tension very well, we have to mix up the layers to make the rim stiff and strong enough. Pressure is not a great feature of a fiber. Just think of a string being pushed [1]). But when mixed correctly, the different angles interconnect through the resin to make it resistant to all kinds of forces [2].
The 3K has a slightly lower stiffness/weight ratio than UDF (Uni-Directional Fiber) sheets of equal fibers, but it makes up by giving the rims a bombproof feature. Why? Because when a strand (or multiple) gets cut in UDF, by crashing for instance, the sheet is compromised and the tear will expand through a larger part of the sheet at continuous workload. A weave will stop the tear because it is intervened by the crossing layer of strands [3].
Although it is not advised to ride with a 'hole' in your rims, situations can occur where you might not know of a damaged rim or it is not an option to stop right away. Then you have the extra safety of the 3K weave to get you home.
Durability is one of the goals set by FFWD from the get-go. Therefore we demand more of our rims than we would if we had lower spoke tensions in our wheels or if we had weight limits* for our wheels.
For instance, our rims have reinforced strips [1] where the spoke holes are placed, to ensure that high tensions are not an issue. In a regular rim [2], you can't control the specific stresses by layup only. The spoke force is concentrated around the nipple hole. With a pre-defined reinforcement strip [3], we 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. The rims are now capable of withstanding a spoke force of 300kgf. This force is around the same as the ultimate strength of the spoke itself. And we only use the best and the lightest spokes available on the market today, so you can imagine how durable the wheels are when the rims are laced up by professional wheel builders.
The fact that we use a clear coat [4] on our rims (except for the Discs) is also done with the focus on durability. It adds a little bit of weight (think of 20g for a F5 rim), but we are pretty proud of our decals and we therefore want to keep them on the rim as long as possible. If the decals weren't protected by the clear coat, they would very likely get damaged by cleaning, weather, etc. Plus it gives you that smooth overall look. Carbon shine all the way!
Furthermore, we feel that the weight factor is much less important than the aerodynamics factor. See up ahead in the FAQs section.
Another factor, although small, is the use of 3K carbon as the outer shell. This material has a slightly lower stiffness/weight ratio than UDF sheets of equal fibers, but it makes up by giving the rims a bombproof feature.
* The F2R does have a weight limit, see FAQ for further information.
FFWD's focus is on fast, durable wheels. We don't consider weight to be of equal importance although we of course try to make the wheels as light as possible within the standards we have set.
Let's take a look at the forces that effect a system like a bicycle plus rider. If the conditions are; flat road, no wind, sea level and frictionless bearings, then the forces are rolling resistance, air resistance (frontal area) and wheels drag [1].
Some conclusions can be drawn from this graph:
- 1. The rolling resistance is constant. It depends on weight, tire and type of surface.
- 2. Both air resistance and wheel drag increase non-linear.
If you look at the formula [2] that calculates Drag Force, you can see that the speed v is squared. This means that when the speed of the system doubles, the Fd quadruples:
(1*v)^2 = v^2
vs.
(2*v)^2 = 4*v^2
And since Power (Pd) is Force x Velocity (Fd*v), the Power required to overcome the aerodynamic drag increases as the cube (^3) of the velocity. So, if you double the speed, you need eight times the Power, because you do four times the Work in half the Time.
Okay, now you should 'feel' the importance of lowering air resistance as much as possible if you want to go fast...forward.
But what about weight vs. aero?
Well, when you decrease weight (-10%), the rolling resistance decreases as well. But the lighter wheels usually also create more drag (let's say, +10% Cd, but this could easily be more), so that when you add the extra drag to the F4 and put the results in a graph [3] you can see that there is a certain point (break-even) where the weight becomes a less important factor than drag for higher speeds. In this example it is around 4.5 m/s (16.2 km/h).
When the drag is more than the assumed +10%, then obviously the break-even point will be at a lower speed -> the advantage of the lower weight will turn into a disadvantage even sooner.
Remember that in the beginning of the text I assumed some conditions to be constant or absent. For instance, no wind means that the air resistance acts directly from the front. It becomes a different story when there is a wind coming from a certain angle. This will influence the speed-power comparison very much and the aero characteristics of the wheels play an even bigger role in this case.
Same goes for the 'flat road' condition. If you are on a climb, the gravity plays a big part in the equation. As with the air resistance vs. weight, you also reach a break-even point (certain angle of the road) when the advantage of the lesser air resistance is gone because the climb becomes too steep (gravity pulls too hard on the weight of the wheels).
No, you can't!
There are two very important reasons for this.
1) The brake pads we supply with our wheels are for carbon rims only, because of the special compound of which the pads are made. This compound mix is not suitable for optimum brake performance on alloy surfaces.
2) It is also very important to keep the brake pads that are used for alloy rims separate from the ones you use on carbon rims. It is very possible that alloy splinters can accumulate on the pad when braking. And when you would use these pads on carbon rims, the splinters will scratch the carbon and possibly damage the fibers. This is an important safety issue which must be avoided. So, please think of your pads when you have different wheel sets.
It means quality, durability and longevity!
FFWD laced wheels are built in such a manner, that they stay true throughout their lifetime when used in normal conditions.
- Laced up by hand
- Stress relieving and spoke bending for correct alignment from hub to rim
- Trued by hand
- Spoke tension is measured in every spoke to ensure equal tension
We have master wheel builders who have years of experience in lacing and truing wheels. These people are passionate about cycling, but crazy about wheels. You could say that it's their oxygen. So, you can imagine that they would do anything to prevent a wheel being released to the market of which they are not proud.
If the information on this website is not sufficient to make a confident choice, it is always possible to contact FFWD by mail or phone.
Factors you have to consider are:
- Type of terrain.
- Intended use (racing and/or training, hills and/or flat courses).
- Weather conditions (wind, sea side)
- Rider factors (weight, power, riding style)
You can find a comprehensive instruction on the Vittoria site or on the Schwalbe site.
NEVER sand a carbon rim!! This instruction only applies to alloy rims.
NEVER use a metal tool to mount the tire!!
The Control wheels come with four additional spokes in the front and rear wheel compared to the standard wheels.
Our recommendation to choose a Control version is when the rider weight is around 90 to 95kg or more.
The extra power that heavier riders are able to put onto the wheels is split over the additional spokes resulting in a stiff and rigid wheel set.
The Control wheels can be recognized by the 'C' in the model name where the standard wheels are indicated with an 'R' like F5R and F5C for example.
The standard wheels are build with 20 spokes in the front and 24 spokes in the rear. Control wheel sets are build with 24 spokes in the front and 28 spokes in the rear.
Our Control models are:
- F4C (tubular)
- F4C-c (clincher)
- F5C (tubular)
- F6C-c (clincher)
FFWD offers only wheels with the red/white decals which are under the clear coat for durability.
We are working on a neutral design which will be optional for a few models. This neutral design will however not be available before late summer 2010.
Color options you might have seen have been produced especially for a bike brand. We are also aware of some sticker companies that produce decals in different color options. These decals are however applied on top of the clear coat.
All rims are molded with a process we call EcomTM (Equal Compression). This means that the rims are molded with a custom-made air bag that has the inner shape of the rim [1]. This makes sure that the pressure/compression is equal on the entire inner surface of the rim. Result is a practically void less rim section and a smooth wall on the inside of the rim. Without voids, the carbon sheets are completely fused into one system. The rim structure is much better and you can make the rim lighter and stronger.
EcomTM also provides for a smooth inside (no wrinkles!) which is a great feature and not common for carbon rims. This is for instance very beneficial for the nipples. Just imagine how the force of the spoke tension is applied through the nipple seat onto the rim itself. If the nipple seat isn't smooth, the transition of the force isn't clean and optimal. This might cause spoke, nipple or spoke hole failure in future. FFWD rims are made with EcomTM which ensures longevity.
The 3K has a slightly lower stiffness/weight ratio than UDF (Uni-Directional Fiber) sheets of equal fibers, but it makes up by giving the rims a bombproof feature. Why? Because when a strand (or multiple) gets cut in UDF, by crashing for instance, the sheet is compromised and the tear will expand through a larger part of the sheet at continuous workload. A weave will stop the tear because it is intervened by the crossing layer of strands [3].
Although it is not advised to ride with a 'hole' in your rims, situations can occur where you might not know of a damaged rim or it is not an option to stop right away. Then you have the extra safety of the 3K weave to get you home.
There are two very important reasons for this.
1) The brake pads we supply with our wheels are for carbon rims only, because of the special compound of which the pads are made. This compound mix is not suitable for optimum brake performance on alloy surfaces.
2) It is also very important to keep the brake pads that are used for alloy rims separate from the ones you use on carbon rims. It is very possible that alloy splinters can accumulate on the pad when braking. And when you would use these pads on carbon rims, the splinters will scratch the carbon and possibly damage the fibers. This is an important safety issue which must be avoided. So, please think of your pads when you have different wheel sets.
As long as the brake pads are designed for carbon rims you can use those as well. For instance, besides our own pads we also have good experiences with the Swiss Stop Yellow Kings.
There are a few general things we can say when comparing the two types.
Tubular / Clincher:
- lighter / heavier tire (in weight)
- mostly better ride qualities / mostly lesser ride qualities
- lighter / heavier rim (in weight)
- spare tire is heavy / spare inner tube is light
- changing a flat tire is mostly hard because of the glue / changing an inner tube is pretty easy
- small chance / big chance on running flat after a pinch (rim hits the ground and crunches the tire)
- more / less costly per tire
- smaller / wider range of choice as far as price and level
I guess the important thing is that you should make a choice depending on your specific use and budget.
But, in the end for every situation is a solution. For instance, are you heading out on your own for a long trip? You can use tubulars, but do take along a spare, a Pit-Stop container (or Stan's or Tufo's Sealant) and make sure the cement isn't fully hardened, so that you can pull of the tire with your hand. Or you can go out on clincher wheels and just take along a spare inner tube and two (plastic!!) tire levers.
You can find a comprehensive instruction on the Vittoria site or on the Schwalbe site.
NEVER sand a carbon rim!! This instruction only applies to alloy rims.
NEVER use a metal tool to mount the tire!!
NEVER use a sharp or hard tool to scrape off the glue. You could damage the carbon rim and endanger the structural integrity.
The road hubs are a high quality choice from a reputable hub manufacturer. The company proved to be a reliable partner that makes almost a million hubs each month. The hubs are thoroughly tested under various conditions by pro-riders. Especially the feedback we got from the cyclocross riders gave us the confidence that these hubs are durable enough for FFWD.
Front: 83g / Al7075-T6
Rear: 265g / Al7075-T6 / Alloy cassette / 4 sealed cartridge bearings
The FFWD hub is currently compatible with Shimano 9/10s or Campa 9/10/11s. Like on the DT hubs, the exchange from Shimano to Campa and vice versa is very easy.
Before 2010 the FFWD Campa hubs were not compatible with the 11speed cassette. For riders wanting to upgrade their pre-2010 FFWD hubs to Campa 11sp, FFWD is offering a 0,5mm spacer which should be placed underneath the cassette body. Contact FFWD for more info.
A ceramic is an in-organic, non-metallic material, which can be used for domestic (clay pottery, sanitary ware) and industrial applications (bricks, tiles).
When we speak of 'ceramic bearings' we refer to the balls that are inside of the bearing. These ceramic balls are typically made from (SiN4) ceramic silicon nitride and have greater hardness and a smoother surface finish than steel balls. This means less wear and higher longevity.
They deform less under high loads (-> smaller contact surface -> less friction)...
...are almost not affected by heat (-> less friction)...
...and are resistant to oxidation.
Ceramic bearing balls also require less lubricant, resulting in increased bearing life.
Small drawback is the higher cost.
However, we cannot guarantee that DT Swiss will still warrant your modified hubs. You might want to check with DT first before installing making alterations to your hubs.
Rear: shell - 1 x 6902RU (61902-RZ) - ø15x28x7
1 x I5267-2RS - ø15x26x7
Rear: free body - 2 x 15268-2RS - ø15x26x8
Front: shell - 2 x 6802 - ø15x24x5
J-bend spokes are widely available at many bicycles stores and distributors. You can also contact FFWD.
Let's say a rider is on a hill and pushes the pedal with a force equal to 150kg [3]. 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*(175/78)*(55/23) = 800kgF [4]. 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 -> not a good thing).
So, therefore FFWD decided to put in an extra 20g, but in exchange we can build wheels with a higher durability, stiffness and more responsiveness. For those who feel that they need more rigidity than our standard 20/24h lacing (cyclocross for instance), we propose the ControlTM version with 24/28h lacing. ControlTM is available on most models.
As for the F2R-190, this is an ultimate lightweight climbing set, so we of course use alloy nipples for optimum performance and weight reduction.
Rear wheel is pre-tensioned with 110/120kgF Drive side, 90kgF Non-Drive side.
(F2R wheels are set up with 10kgF less for both the front and rear wheel)
























