Freehub Vs. Freewheel (In-Depth Comparison)

Freehub Vs. Freewheel

Freehub and freewheel are transmission devices for coupling bicycle cassettes, and transmission devices have unique characteristics and differences.

This article will discuss both devices and their differences

Inside the freehub and freewheel transmission, there is a group of bearings. These bearings differ from the ones in the central axle of the wheel. A group of pawls that are spring-load work in unison with the bearings. Anytime you pedal, the pawls fasten to rotate the wheel forward.

What Is Freehub?

The freehub is a ratcheting mechanism that conveys the pedal motion to the ground.

It lets your legs rest as the bicycle continues moving. The freehub has a group of sprockets with this ratcheting mechanism that involves the wheel as you pedal, pushing you forward. 

Freehub Vs. Freewheel

This mechanism uncouples anytime you rest from pedaling. This action permits the wheel’s movement without involving the gears.

Instead, a group of splines slides onto gear sprockets on a freehub’s exterior surface.

The sprockets on the cassettes, which are called speeds, lock into threads of the freehub.

#1. How the Freehub Operates

Most freehubs use either pawl or ratchet systems to operate. These systems are responsible for involving the wheels and the freehub during pedaling.

The system is also responsible for uncoupling the wheels from the freehub. Let’s take a look at these systems individually.

#1. Pawl Freehub System

The pawl freehub system features sprung levers linked to a notched drive. Another name for these sprung levers is pawls.

In one location of the bicycle’s hub, they angled outward. In another spot, they attach to a notched drive ring to convey energy to the wheel.

The springs shove the pawls out of their compartments during pedaling. When you aren’t pedaling, the pawl’s angle signifies that the pawls are pressing against the springs.

The springs grind against the teeth, which makes a distinctive clicking noise. Pawls can number between two to six; however, the number differs across freehub designs.

In this design, the pawls are generally inside the freehub. They are only shoved outward into the hubs notches.

Pawls feature in the hub lip’s interior edge in other arrangements. For example, the pawls face inside near the freehub’s teeth

#2. Ratchet Freehub System

The ratchet freehub system is also spring-loaded; however, the pawls are absent. A ratchet freehub utilizes twin-toothed rings that lie side by side on a level plane.

The engagement mechanism operates comparably as the teeth on either ring lock together. In this system, the rings are fixed in a fashion that engagement is in one way.

In addition, this system has a characteristic frequent mechanical contact that uses every tooth. Although each ring grinds past the other with a spring, ensuring they maintain contact.

There is a low likelihood of error in this system. The reason is that there’s a single spring, and every tooth is engaged.

What Is a Freewheel?

Freewheel is a system where the cogs are linked right into the hub.

Anytime the driven shaft spins and outpaces the driveshaft, the system decouples the driveshaft from contacting the driven shaft.

During pedaling, the freewheel remains tight due to the torque on the chain.

#1. How the Freewheel Operates

A regular freewheel mechanism features dual spring-loaded rings that are saw-toothed.

Each ring pushes against the other. In this process, the toothed sides are linked similarly to a ratchet.

As they spin on one route, the drive ring’s saw-like teeth are secure with driven ring’s teeth.

This action makes them spin at a similar pace. Anytime the drive ring reduces speed or stops spinning, the drive ring’s teeth slide over the teeth of the drive ring.

This process allows the drive ring to maintain its momentum, creating noise. This noise is relative to the variance in speed of the driven ring to the driving ring.

A more elaborate design features spring-loaded metal rollers within a driven chamber.

In this design, if the metal rollers spin slower, they’ll slide into the chamber. The rollers secure in with the compartment causing it to turn together with the rollers. 

What Is the Difference between Freehub and Freewheel?

The difference between freehub cassettes and a freewheel is where the engineers have installed the coasting device.

The coasting equipment in a freewheel system attaches itself to gears.

The word ‘freewheel’ denotes the entire set of gears featuring the coasting device within—the freewheel screws into a group of threads found on the wheel hub’s right-hand area. 

The coasting device is the wheel hub’s sub-unit in the freehub mechanism. This set of gears is a unit having non-moving components, which are called a cassette.

This cassette slips into position onto the body of the freehub. It is kept in place by several splines or ridges and secured by a cassette lock ring.

The axle bearings on the freehub’s core hub are more spread-out than those on the freewheel axle.

The bearing’s position on the freewheel was the general design for decades. The axle was also adequately strong for many applications. 

Some other differences between freewheel and freehub include;

FreewheelFreehub
Usually features 5, 6, or 7-speeds.Typically have 7, 8, 9, or 10-speeds.
If the sprockets rotate backward, the extractor splines won’t turn.The lock ring splines rotate with sprockets if they rotate backward. 
Anytime the Freewheel mechanism wears away, you can change the whole freewheel. If the freehub mechanism wears away, you extract the speed cassette. Then, change the freehub, and fix back the cassette.

Freehub Vs. Freewheel at a Single Speed?

The freehub and freewheel systems are in regular use in single-speed transmissions.

The operating principle for either design is no different from its multi-speed counterparts. A freewheel has a single-speed feature, a coasting device fitted into one cog. 

This cog screws onto the central hub of the wheel. This mechanism is common in BMX bicycles, single-speed children’s bicycles, and other single-speed highland bicycles.

A freehub has single-speed features similar to splines found in a freehub using multi-speed.

However, the body of the freehub is only smaller to house one cassette cog.

How do I know if I have a Freewheel or Freehub?

To confirm if a sprocket is either a freewheel or freehub system, take out the bicycle’s hind wheel.

Locate the assembly tool attached to the sprocket piece. Rotate the sprocket rearwards and see if the assembly tool imitates the cog’s spin.

You have a freehub cassette system if they spin as the cog does. If the assembly tool doesn’t turn, you have a freewheel mechanism.

The cassette core utilizes a freehub mechanism. This cylindrical device ratchet’s anti-clockwise when coasting and secures clockwise when pushing the bike during pedaling.

The freehub mechanism is a clutch installed on the hub’s body. 

The body of the freehub, on the other hand, consists of a sequence of splines found on the exterior shells.

Cassette sprockets slip against these splines. A lock ring meshes inside the freehub holding the cogs or sprockets in position.

Removal of the cogs will leave the ratchet freehub on the hub’s bodice. Many contemporary bicycles employ the freehub mechanism.

Earlier bikes sometimes consist of a big exterior thread hooked onto the hub.

The cogs, together with the ratchet body unit referred to as a freewheel, meshes with the hub.

Anytime the freewheel is detached with a freewheel removal tool, the ratcheting device and the cogs come off. You can purchase a freewheel removal tool here. 

Do I Have a Freewheel or Freehub?

Sprocket pieces are available in freewheel or freehub standards. These standards are used based on the kind of rear hubs.

Freewheel is fastened into the rear hub while freehub glides into the splines of the hub—the freehub clasps into position with a unique lock ring. 

Furthermore, the rear hub’s extreme ends vary for every kind, so it is simple to recognize the standard without taking out the sprockets.

Freewheels have sprockets that are screwed together with no chance of changing them. Freehubs have slack sprockets secured together by screws or bolts.

Conclusion

The freewheel and freehub are bicycle mechanisms that allow you to pedal the bicycle.

Freehub uses a ratcheting mechanism, while freewheel uses overrunning clutch that separates the driveshaft from the propeller shaft.

Freewheel is fastened into the rear hub while freehub slides into the splines of the hub.

Josh Matthews

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