Will A 525 Chain Fit A 520 Sprocket

Technically, yes, a 525 chains can indeed be directly into the 520’s tray, because their pitch is exactly the same, are 5/8 inches. But don’t just ride on the road. Although the pitch is right, the inner width of the sleeve of the 525 chain (5/16 inch) is much wider than the 520 cone (thickness 1/4 inch). This size drop will produce a great amount of lateral open (commonly known as left and right). If you try to save money and stick to this combination, it is basically to scrap the transmission system in advance. If you ride it, your hands will feel numb and your feet will feel numb. It will also bury fatal safety hazards-such as dropping chains at high speed, stuck rear wheels, or directly pumping out the engine box.

If you are still wondering if you can deal with it this way, it is recommended to understand the mechanical principles behind these numbers first. Next, I will carefully disassemble why this blind collocation is completely dead.

Understanding The Dimensions: Pitch Vs. Width

To understand why the 525 chain can be sleeved into the 520’s tooth plate, we must first look at how the motorcycle chain is labeled. The focus is on the “pitch” and “roller width.

Pitch of the right (“5” at the beginning):

525 and 520 chains start with the number “5”, which represents the pitch of the chain, that is, the distance between the two pins. Both are 5/8 inches. Since the pin spacing and the tooth spacing of the tooth plate are completely engaged, the 525 chain is naturally and smoothly placed without any jam. Many riders put it up and thought it was a perfect match. In fact, it was a big mistake.

Width not on (“25” versus “20”):

The real hell difference is wide inside the roller. The inner width of the 525 chain is 5/16 inch, while the cutting thickness of the 520 tooth disc is only 1/4 inch. You hang the wide chain on the narrow tooth plate, and there is a big gap in the middle.

The Mechanics Of “Side Slop”

The mechanical tolerances of the motorcycle transmission system are designed to be extremely strict. Only in this way can the power of the engine be transmitted to the rear wheels without any difference. You put the 525 chain and the 520 teeth together, and this tolerance is completely destroyed.

Because the inner width of the 525 is much thicker than the teeth of the 520, the chain cannot maintain a straight track at all. Instead, there is severe lateral swing, which we usually call “lateral volume” or “left and right swing” in the store “. As long as the tooth plate rotates, the chain will keep moving left and right on the thin tooth plate instead of staying in the middle. This extremely unstable mechanical bite is the root cause of all the car damage and even death in the back.

Abnormal Wear And Severe Vibration

If you feel that it doesn’t matter if you are a little bit absent and ride hard, mechanical retribution will come to you immediately.

One hundred percent of abnormal wear:

Because of the left and right gaps, the inner chain pieces of the 525 chain will frantically beat and rub the side edges of the 520 cone teeth. This abnormal friction will quickly cut the metal off the teeth and chain like a file. A set of transmission that could have run tens of thousands of kilometers, according to this method, the life span is directly shortened to a fraction of the original. Before, I removed the dental plate that was gnawed like a blade, which was basically caused by this reason.

Severe vibration:

The right-sized chain is extremely slippery on the crankset. But a chain that is too wide will violently jump left and right on the crankset as you accelerate or decelerate. This kind of vibration will be transmitted to the pedal along the transmission system and then directly to the rider. The riding texture is extremely bad and very irregular.

Fatal Safety Hazard

Never use 525 chains on the 520 tooth plate. The core reason is by no means as simple as wear and vibration. This lateral volume actually turns your transmission system into a time bomb, which can cause extremely bad accidents at any time.

High-speed chain drop:

When you are driving at high speed or bending and tilting, the excessive lateral clearance makes it very easy for the chain to derail directly from the teeth of the crankset. Imagine suddenly dropping the chain at a speed of 100 kilometers per hour and losing all the power in an instant. The scene definitely makes people sweat.

broken chain and rear wheel lock:

In case the fallen chain gets stuck in the rear wheel or the rear flat fork, the instantaneous pulling force will probably tear the chain directly. To make matters worse, the chain twisted together will instantly lock your rear wheel. The rear wheel suddenly locks up on the highway, and the result is basically a loss of control and a serious crash.

Blow engine box:

If a mismatched chain breaks under stress, the front half of the thing becomes a high-speed steel whip swung by the front tooth plate. It will pull forward directly with huge inertia and easily penetrate your aluminum alloy engine box (commonly known as the box).

Author: Jason Miller
Hi, I’m a certified motorcycle mechanic with over 14 years of hands-on experience specializing in drivetrain optimization and repair. Throughout my career in the shop, I’ve seen firsthand the catastrophic engine damage and severe accidents caused by mismatched chains and sprockets.