06 March 2024

Hooked vs. Hookless

Fulcrum Wheels

Performance, safety and compatibility of Hooked vs. Hookless rims

Going against the flow is not necessarily a virtue and neither is blindly following market trends, especially if there are valid reasons to take a different approach to everyone else. 
At Fulcrum we don’t have dogmas, we simply build our product philosophy by taking well-considered choices and assessing the pros and cons of every solution. This is the approach that we applied when we decided whether to remove or not the hook from the rims of our road and gravel wheels.
Let’s not get ahead of ourselves here. Let’s start from the beginning. What’s the hook? It’s the part of the channel of the rim that ‘hooks’ the tyre. The sides of the channel can either have a hook or a flat surface. The role of the hook is to provide a safe seating area for the tyre and prevent the tyre from demounting. 


In recent years we have witnessed a rapid spread of the hookless solution. The process has been made possible especially due to the consolidation of tubeless technology, which allows riders to use lower pressures and that, as long as the size of the channel is increased, provides greater comfort and performance. Moreover the growth of hookless rims has been driven by wheel manufacturers looking to lower production costs. 
But at Fulcrum we firmly believe in the traditional solution and we use hooks on our road rims and mini-hooks on our gravel rims. We have chosen this option for two reasons. 
First of all we want to guarantee the utmost compatibility between our wheels and the tyres available. As of today a hookless setup is not a guarantee of optimum compatibility. Finding out which tyres can be fitted on hookless rims means pouring over the compatibility tables of the various manufacturers and the choice is very limited.
The second, and even more significant reason, is safety. Hookless rims are safe only within a specific pressure range. Many users are still unaware of this pressure range and tend to over-inflate their tyres. Hooked rims guarantee the maximum level of safety even if the inflation pressure is exceeded.
Moreover we have tested the theses that hookless rims provide higher performance levels because they provide a cleaner transition between rim and tyre and therefore ensure a better contact patch and improved aerodynamics. Our tests have revealed that, with the same sized rim channel and tyre, the change in the profile of the tyre is so insignificant that it has no effect on aerodynamics, rolling resistance, reactivity and comfort


Lastly it’s worth examining the production process and the consequent costs involved in the construction of a rim with a hook. We all know that the moulds used to produce carbon rims are amongst the most costly components of the entire production process of a wheel and, obviously, the more complex they are the greater the costs.
At Fulcrum we produce the moulds and all the equipment used in the production process in-house here in Italy. This allows us to test innovative solutions whilst maintaining full control of the entire process.
When producing hooked rims in particular, the most common procedure used is to remove the excess material by milling, which requires a second machining phase and its relative costs, as well cutting the fibres, increasing the vulnerability of the rim. Alternatively, more competent manufacturers use complex moulds, which allow the hook to be created without additional machining processes, but that involve high production costs and are more difficult to manage. 
The innovative process that we have developed in-house, after numerous experiments, uses special inserts for the moulds that overcome the complexities of the aforementioned methods. Thanks to this solution we are able to produce an extremely high quality product directly from the mould, without having to compromise its indispensable characteristics.  
In view of the fact that hookless designs don’t provide significant performance benefits, we think that hooked rims still offer undeniable advantages. Despite being more complex in terms of production, we have learnt how to master the process and still prefer them over the hookless design. Not just for the sake of going against the flow or to be different, but simply because we believe they are the best solution in absolute terms.
Long live the hook!