The Shimano FD-5800 [paid link] front derailleur belongs to the 11-speed 105 series, while the FD-4700 [paid link] is part of the 10-speed Tiagra group. At first glance, both models share a similar appearance and design language, but their mechanical performance and compatibility differ significantly. Understanding these differences is essential for riders choosing the right component for their drivetrain or upgrading their road bike.
Design and Construction
The FD-5800 [paid link] features a wide-link design that improves rigidity and reduces flex during shifts. This design increases precision and consistency, particularly under load. The derailleur body incorporates forged aluminum with stainless steel hardware, providing a balance of strength and weight savings. In comparison, the FD-4700 [paid link] uses a similar wide-link design but with slightly heavier materials, making it more cost-effective but less refined in terms of weight optimization.
Another notable difference is in the actuation ratio. The FD-5800 [paid link] is built specifically for Shimano’s 11-speed road shifters, while the FD-4700 [paid link] uses a unique cable pull ratio tailored only to Tiagra 10-speed shifters. This makes the FD-4700 incompatible with most other Shimano 10-speed or 11-speed shifters, while the FD-5800 integrates seamlessly within the entire 11-speed ecosystem.
Shifting Performance
The FD-5800 was designed with Shimano’s “Long Arm” lever design, which reduces shift effort and provides a more positive, crisp engagement. The result is faster, smoother shifting between chainrings, even when pedaling hard. The FD-4700, although an improvement over earlier 10-speed derailleurs, does not reach the same level [paid link] of smoothness and requires slightly more force at the lever.
Riders upgrading to the FD-5800 will notice a lighter feel at the shifter and a reduction in chain rub when properly adjusted. The cage design also allows for more clearance, improving chain line management with compact or standard chainring setups. The FD-4700, while functional, can be more sensitive to cable tension and alignment.
Compatibility Considerations
Compatibility is where the biggest difference lies. The FD-5800 is fully compatible with Shimano 11-speed road components, including shifters, chains, and cranksets from the 105, Ultegra, and Dura-Ace groups of the same generation. This makes it an ideal choice for riders looking to build or maintain an 11-speed drivetrain with flexibility in component selection.
The FD-4700, however, is locked to the Tiagra 4700 system. Despite being a 10-speed derailleur, it does not work with older 10-speed Shimano shifters because of its revised cable pull ratio. This restricts its use to riders running a complete Tiagra 4700 drivetrain, limiting upgrade paths compared to the FD-5800.
Adjustment and Setup
Both derailleurs feature Shimano’s support bolt for added frame stiffness, but the FD-5800 offers a smoother adjustment process. The longer lever arm reduces sensitivity to small errors in cable tension, making the derailleur easier to fine-tune. Limit screw adjustments are straightforward, with clear markings for high and low stops. The FD-4700 requires more precise cable tension management, and improper adjustment is more likely to result in chain rub or missed shifts.
Performance in Real-World Use
In real riding conditions, the FD-5800 consistently delivers cleaner and quicker shifts, especially under power. Riders using compact chainsets or riding in hilly terrain will benefit from the reduced shift effort and improved chain management. The FD-4700, while competent, does not provide the same crispness when shifting under load and may demand more frequent micro-adjustments during setup and use.
Weight and Durability
The FD-5800 typically weighs less than the FD-4700, reflecting its higher position in Shimano’s lineup. Durability, however, is comparable. Both derailleurs are designed to withstand heavy use, but the FD-5800’s premium materials and construction give it a slight advantage in long-term wear resistance.
Which One Should You Choose?
Cyclists already running an 11-speed system should choose the FD-5800, as it provides better performance, compatibility, and long-term flexibility for future upgrades. Riders with a complete Tiagra 4700 groupset should stick with the FD-4700 for full system compatibility. Attempting to mix the FD-4700 with other shifters will result in poor performance, making the FD-5800 the more versatile choice for most cyclists.
In conclusion, the Shimano FD-5800 front derailleur is the superior option for riders seeking precision, smoother shifting, and integration with the broader Shimano 11-speed ecosystem. The FD-4700 remains a strong choice within its specific 10-speed Tiagra system, but its compatibility limitations make it less adaptable for riders planning future upgrades.