Yes, there can be downsides to putting a longer fork on a motorcycle. Here are a few potential issues to consider:
Handling and stability: Altering the geometry of a motorcycle by installing longer forks can impact its handling characteristics. Longer forks can change the rake and trail, affecting the bike's stability, maneuverability, and responsiveness. It may result in slower steering response, decreased stability at high speeds, or changes in the bike's overall balance.
Ground clearance: Longer forks can reduce the ground clearance of the motorcycle. This may lead to scraping or bottoming out of the frame, exhaust, or other components when going over bumps, dips, or during aggressive cornering.
Suspension performance: Longer forks may require adjustments or upgrades to the suspension system to maintain proper balance and performance. The original suspension components might not be optimized for the longer fork, resulting in suboptimal suspension behavior, reduced comfort, or compromised handling.
Frame stress and compatibility: Installing longer forks may introduce additional stress on the motorcycle's frame and other components. The frame's structural integrity and the compatibility of other parts, such as the front wheel, fender, and brake system, should be carefully evaluated to ensure they can handle the changes.
Cost and modifications: Installing longer forks typically involves additional costs for purchasing the new forks, modifying or replacing other parts, and potentially seeking professional assistance for the installation. It may also require adjustments to the bike's controls, such as handlebars, cables, and wiring.
Before considering a fork length modification, it is essential to consult with an experienced motorcycle technician or suspension specialist. They can provide guidance specific to your motorcycle model, your riding style, and your desired modifications. They will be able to assess the potential downsides and advise on the best course of action to achieve your desired outcome while maintaining safety and performance.