When developing the Tracomp technology, our goal was to significantly improve the global performance of a wheel intended to climb the highest mountain passes. Not just incremental changes, but massive and disruptive improvements that provide tangible and impactful benefits.
A thorough analysis of cyclists needs made it obvious that we had to tackle three parameters simultaneously. None of these needs were optional in engineering a new benchmark for the ultimate alloy wheel.
Those parameters are:

At the end of our journey, we created a technology that enabled the wheel to have significantly improved stiffness while reducing weight and maintaining the durability Mavic is known for. Here is how.
1. LATERAL STIFFNESS
1.1. Parameters influencing lateral stiffness
What are the parameters that influence lateral stiffness of a bicycle wheel?
Here is a list of the parameters that have the greatest impact on the lateral stiffness of any bicycle wheel, their level of impact and the downside for the cyclist:
IMPACT ON LATERAL STIFFNESS | DOWNSIDES | |
1. Rim stiffness | Rim stiffness =< 10% wheel stiffness => low impact | Increase inertia or weight, depending on material => slower acceleration |
2. Spoke length | Up to 7% | Short spokes means deep dish rim or high flange hub => heavier |
3. Flange diameter | Up to 6% | Huge weight increase at the hub è heavier |
4. Lacing | Up to 4% according to method used | Impact on spoke tension balance between the 2 sides of the wheel => less durable |
5. Spoke tension | Low impact but… | Too high tension => fatigue + rim bucklingToo low tension => unloaded spoke…=> less durable |
6. Spoke stiffness | Up to +36% | Weight penalty, depending on material è heavier |
7. Increased wheel dish | Up to +50% | Huge impact on spoke tension balance (very low tension on non drive side) => less durable |
So, to reach our goal of significant improvements, we have to act on spoke stiffness and wheel dish. But we also have to take into account the downside of playing with those elements.
1.2. Lateral stiffness measurement
First, lets explain, quickly, lateral stiffness. To have an efficient wheel there must be a resistance to the lateral (side-to-side) flex when force is applied. The stiffer the wheel, the more efficient. So, a high degree of lateral stiffness is desired in order to have the most efficient power transfer to the road.
Second, let’s have a look at how to accurately measure lateral stiffness. The wheels needs to be locked by the hub in a solid and infinitely stiff fixture. Then, we progressively apply a load on the side of the rim at the point that represent the contact of the wheel on the ground. The load applied must represent the power of a solid rider while sprinting, This is the condition where you need to count on your wheel. We typicaly apply a lateral load of 20 décanewton (DaN) representing the lateral load achieved during a sprint by a high level cyclist. This process results in a graph which represents the amount of deflection with 0 to 20kg of side load.

1.3. Interpreting the result
The graph drawn when applying the load is this one :

The red circle shows that at a point (sooner or later depending on the wheel), the deflection increases very rapidly for just a small incremental amount of side load.
This happens when a spoke becomes lose. Then, he does not support the integrity of the wheel anymore. The consequences for the cyclist :
- The wheel deforms: the rider will feel the wheel flexing
- The wheel is noisy
- Complete loss of tension affects the wheel’s durability
So, to increase the lateral stiffness, it becomes obvious that we must
- prevent spokes from losing tension under high load
- At any load minimize the amount of deflection
That would mean that the slope on the graph becomes steeper and with no inflection point.
The usual solution used by many wheelbuilder to avoid those sudden loss of tension is to increase the spoke tension
If we do so and put the same wheel with higher spoke tension on the same bench here is what you get:

Indeed, there is a delay in the moment where the spoke will lose tension: more load is needed to cause that spoke loosening.
BUT we’ve created more issues:
- More stress is applied on the wheel components which limits:
- durability
- Opportunity to save weight
- The wheel is less stiff : at reasonable load, you have more distortion for the same force as the wheel buckles more easily as the result of higher tension throughout the whole wheel (the curve is flatter).
1.4. The 2 most effective solution to increase lateral stiffness
Solution #1: stiffer spokes
The spoke is the 1st wheel component which is responsible for wheel deflection. Its elasticity is much higher than that of the rim or hub flange.
A stiffer spoke will bring less elasticity:

Solution #2: larger bracing angle with no spoke loosening
Rear wheels are asymmetrical because spokes have to make room for the cassette on one side, and have plenty of space on the other side.

When applying the load, we get:

When the spoke tension gets down to 0, we have the extra deflection talked about in the section above.

1.5. How TRACOMP solves the issue of higher lateral stiffness
As seen above, we need stiffer spokes
The spokes of a Tracomp wheels are made of carbon. When tensioned (the TRAction mode), carbon doesn’t stretch as much as steel or alloy and the wheel deflection is reduced :

Then, when a regular spoke will lose its tension under high load, the Tracomp spoke will enter into its COMPression mode to maintain the lateral stiffness at a constant level, avoiding the sudden loss of stiffness :

1.6. How does a Tracomp wheel achieve this?
The spoke is clamped on both ends :
- At the rim thanks to Fore® technology
- At the hub thanks to the Tracomp ring
The spoke is rigid and does not flex when compressed :
- Material : multidirectional carbon fiber (intermediate module) for the highest impact resistance
- Shape :
Tubular
External diameter : 4mm
Internal diameter : 2,6mm
Spokes don’t stretch (Traction) and cannot lose tension (Compression)
The wheel is STIFF whatever the load and even with low spoke tension

1.7. Stiffness comparison

A Tracomp wheel offers a very high level of stiffness (less deflection at equal loads.
A Tracomp wheel will never have spokes losing tension, so there will be no sudden loss of stiffness even under the highest load.


Traditional wheel
Tracomp Wheel
Tracomp wheel lateral stiffness :
- Front: 56 N/mm
- Rear: 56 N/mm
30% STIFFER THAN A TRADITIONAL WHEEL WITH TENSIONED SPOKES ONLY
2. LIGHTWEIGHT & DURABLE
2.1. The benefits of lower spoke tension
As seen on the stiffness section above, on a Tracomp wheel spokes never lose tension, so the tension can be reduced with no negative impact on lateral stiffness.
Less tension means less stress on the hub, spokes and rim. The weight of the wheel components can be lowered with no impact on durability.
Here are CFD simulations of wheels in a static situation (no load applied):


Tracomp wheel
Traditional wheel
We can clearly see that, even in a static mode, because of the constant spoke tension, a traditional wheel is under moderate stress.
A Tracomp wheel however, thanks to lower spoke tension, is under very low stress.
Of course, once in a dynamic mode (ride), the stress difference is even higher.
2.2. The use of the best material for the function
Aluminum rims:
Light, durable, convenient, stiff
sub 370g rims (clincher weight)
Aluminum hubs:
Lighter than any redundant composite application
Carbon spokes:
Light and much stiffer than anything other option, if shaped correctly,
5g per spoke/nipple (VS 7g on Zicral spoke, 8g on steel spoke)
R-SYS SLR : 1295g per set
Ksyrium Pro Exalith SL : 1355g per set
=>Lighter than most carbon clincher wheels
3. About the carbon Tracomp spokes
Since 2010, carbon Tracomp spokes are made from multidirectional, reinforced carbon layers consisting of multiple layers of unidirectional carbon fibers that are oriented in a specific pattern designed for increased strength.
3. ABOUT THE CARBON TRACOMP SPOKES
Since 2010, carbon Tracomp spokes are made from multidirectional, reinforced carbon layers consisting of multiple layers of unidirectional carbon fibers that are oriented in a specific pattern designed for increased strength.
A pin has been inserted between the spoke and its 2 ends to reinforce this area and disperse stress over a larger surface area. This greatly improves the failure resistance of the spoke when a 3rd party object like a pedal or derailleur intrudes into a spinning wheel. The resistance behavior is similar to that of a Ksyrium wheel with Zicral spokes.
The spoke impact resistance has been multiplied by 5x.
Its torsional stiffness is now 3.5x higher.
Tracomp shows the same crash resistance behavior than that of any other Mavic wheel.
8 Comments
Great info about Tracomp wheels. Not all manufacturers are willing to inform people properly. Thanks, Mavic.
Es cierto
Just bought a pair of R-sys SLR exalith …after read all about those wheels in Mavic site…..they are from other world.
Play in front hub out of the box. Contacted mavic. $50 thicker end caps needed to take play out? Could this be right? Why not ship with various end caps or set it up at the factory correctly. Love the wheels otherwise.
i want to buy some zicral
where i can buy?
thank
Hello,
To purchase your Zicral spokes, I advise you to contact one of our authorized retailers who can advise you and provide you with the appropriate spokes set.
For a list of our authorized dealers around Tel Aviv, please visit the following webpage: http://www.mavic.com/shop-finder#city=Tel%20Aviv
Have a nice day!
Mavic
Is the Ksyrium Pro SL compatible with a Campy 10 speed?
Yes it is compatible.
You have to order the ED11 version.