Almost all products are designed with the ‘average person’ in mind, to allow the product to be suitable for a large proportion of people.
Mountain bike suspension is designed to manage specific ranges of loads, and those loads generally come from the weight of the rider + bike and are opposed by the terrain (or vice versa, depending on how you want to look at it).
This means that those who fall on either side of the bell curve are usually lighter or heavier in weight, and are at a disadvantage when it comes to suspension performance.
While there are no exact definitions or thresholds to identify a ‘heavier rider’, riders weighing more than 90kg (200 pounds) are likely to suffer from underdamped compression, initial harshness, insufficient support through the mid/late travel, and/or excessive, sudden end-stroke ramp with standard air spring designs.
Air spring designs:
Many ‘heavier’ riders have a hard time to find the right level of support whilst keeping small bump sensitivity. It comes as no surprise that those who find their air spring lacking mid-stroke support tend to increase air pressures, thus increasing harshness off the top.
Standard air springs are relatively stiff off the top (perceived as harsh on small bumps and initial impacts) and lack proportional mid-stroke support by design, as seen in this air spring curve below:
Lack of enough compression damping:
The heavier you are, the more likely your compression is underdamped. That is, you'll blow through your travel more quickly, even if it is wound fully closed.
Our YouTune calculator available for the Fractive Tuning system
(for Fox Fit4 Dampers only) is a great way to see and understand exactly what the five different valving configurations do to the fork based on your weight and riding style. It shows a "calculated ideal" curve (recommended - blue line) and an adjustment range (lower & upper).
Bottom out tokens:
To complete the trifecta of heavier riders suffering from poor fork performance, riders tend to jam their fork with bottom out tokens as they are constantly feeling like they are blowing through their travel. While this can be a highly effective remedy to bottoming out, overloading your fork with tokens doesn’t directly address the ‘divey’ aspect of your ride (air spring) or blowing through your travel (compression + spring), and can end up increasing harshness by having the fork riding too low in the travel, constantly running into a sudden “wall” of ramp up force.
How do heavier riders benefit from our upgrades?
Smashpot Coil Conversion System
||Secus Air Spring Upgrade
|• Allows heavier riders to have full use of the fork without excessive pressures.
• Zero friction/stiction for supple initial stroke
• Improved mid-stroke support due to linearity of coil
• Hydraulic bottom out control
• Larger negative air chamber delivers supple initial stroke for ultimate small bump compliance
• Proprietary mid-stroke support valve provides support on par with a coil spring and reduces the required end-stroke ramp
• Compatible with volume spacers for end-stroke progression adjustment
Learn more about the Secus here.
More compression damping can be achieved with…more compression damping, commonly completed by re-valving shims. It’s not something we offer for all forks at the moment, however contact us if this is something you need.