Bike chain dimensions. Done!

Installing a new chain. length and direction

When it comes to installing a chain there isn’t really any difference between Di2 and mechanical groupsets. I get asked this question often enough to publish a quick guide on this though, so here we go.

bike, chain, dimensions, done

While there are numerous methods and guidelines on how to size a chain, I tend to stick to the Shimano manuals. These show how a chain should be installed, depending on the type of rear derailleur and cassette size.

Note that these manuals are still relevant even if you’re not using a Shimano chain. they’re derailleur specific, not tied to any chain brand or type.

You see, Shimano has two types of derailleur: Shadow RD and other, or non-shadow RD.

For GRX and 12-speed MTBs, see the off-road chain sizing section below.

Shadow RD

All current and previous generation derailleurs are of the Shadow RD type. This includes the 12-speed derailleurs, 11-speed MTB derailleurs, and the last generation 11-speed road rear derailleurs.

  • DURA-ACE RD-R9250 (12-speed), RD-R9150
  • Ultegra RD-R8150 (12-speed), RD-R8050-GS (medium cage), RD-R8050-SS (short cage), RD-RX805 (clutch)
  • XTR RD-M9050-SS (MTB, long cage), RD-M9050-GS (MTB, medium cage)
  • XT RD-M8050-GS (MTB, medium cage)

For all of these rear derailleurs, sizing the chain is surprisingly simple. This is what you do:

Without routing the chain through the rear derailleur, set the chain on the largest chainring and the largest sprocket.

Have the two chain ends meet at the large chainring, and then add two or three links, depending on the zero point shown in Shimano’s image below:

Basically, if the point where the two chain ends meet is the ‘end’ of an outer link, add three links (left image).

If the point where the two chain ends meet is the beginning of an outer link, add two links (right image).

Then add the quick-link to connect both ends, and you’re done!

Road: Non-shadow RD

What is a non-shadow RD, you ask? Well, all 10-speed Di2 derailleurs and the first generation 11-speed Di2 road derailleurs:

If you’re using one of the older Di2 derailleurs, the chain sizing method depends on the cassette installed on the bike.

Does your cassette have a largest sprocket of 28T or more? Then use the Shadow RD method described above.

Do you have a smaller cassette? With a largest sprocket of 27T or less? You then put the chain on the largest chainring and smallest sprocket, and route the chain through the rear derailleur

Size the chain so that the derailleur’s jockey wheels are at 90 degrees to the ground. This may be a bit cryptic, but the image below should clarify things:

You don’t need to add any extra links, just connect the chain and you’re good to go. Note that this last method only really applies to non-shadow rd derailleurs and cassettes smaller than 28T.

Off-road (GRX and 12-speed MTB) chain sizing

Do you have a GRX (RD-RX815 (2x), RD-RX817 (1x)) bike, or a 12-speed MTB? Shimano’s recommendations for these bikes are slightly different.

This is how you size a chain for off-road use. I’ll assume you’re using a quick-link for all of these. If you’re using a connecting pin, add one extra link.

Hardtail / Gravel

Without routing the chain through the rear derailleur, set the chain on the largest chainring and the largest sprocket.

Have the two chain ends meet at the large chainring, and then add four or five links, depending on the zero point shown in Shimano’s image below:

If you’re using a connecting pin, add one extra link.

Full-suspension bikes

12-speed full-suspension mountain bikes require slightly longer chains. The difference is just one link. Here is Shimano’s recommended sizing method for full-suspension bikes.

Again, if you’re using a connecting pin, add one extra link.

Chain directionality

You’re almost there, but there’s one more thing to keep in mind. Some chains are directional. They’ll either have an arrow ‘printed’ on them, or something that indicates the inside or outside of the chain.

For Shimano chains in particular, pay attention to the text and logos on the chain. These will be on one side of the chain only, and that side should be facing out (away from the frame).

Are you installing a different brand of chain? Then be sure to check the chain manual, or check with the chain manufacturer.

Are All Road Bike Chains the Same?

The chain is the key element to a bike’s transmission. It connects the front part of your bike, or “drivetrain,” to the rear.

You might hear modern bike chains being referred to as “roller chains.” Of all the individual parts that make up a road bike, the roller chain is the component that works the hardest. When your legs work the pedals, the roller chain is orchestrating communication between the cranks and chainrings/sprocket in the front, and the cassette/sprocket and rear hub in the back. They are made up of short “cylindrical rollers” that are held together by “side links.”

You will notice small gaps between the rollers. These gaps mesh with the teeth on a sprocket or chainring, thus driving transmission when turned. For strength, a lot of road bike chains are made of alloy steel, but some performance models feature high-end alloy parts or hollow pins/side plates to save on weight.

While that is the basic functionality of all road bike chains, there are still several factors to consider when looking for a replacement. The type of chain you need will heavily rely upon the kind of bike you are riding and how you plan on riding it. Factors like coatings, materials, manufacturing tolerances, and metal treatments can directly impact the efficiency and durability of a road bike chain.

Coating and Material

A significant factor in determining the price of a road bike chain resides in the coating and materials used to make the chain. Keep in mind: this is a factor that mainly impacts the price of the chain. Lower grades of steel and/or various levels of material hardening can be found between the most expensive chains and the cheapest chains.

The truth is, each brand keeps its specific coating process a secret. You will often find the benefit of each treatment described in the road bike chain’s product description. For example, SRAM’s top-tier chains feature “Hard Chrome,” and it is described as being an expensive process that requires very stringent process control that will result in an extremely hard and wear-resistant surface.

While performance may not generally be affected by the chain’s coating and material, longevity is. The steel in bike chains is often hardened for wear longevity. A high-end coating can prevent rusting, thus boosting its corrosion resistance. Surface treatments like “Nickel Plating” and “Titanium Nitride Plating” are used for giving smaller parts of the chain a higher level of abrasion wear resistance, thus allowing it to retain its function over a long period.

Besides longevity, the goal of a chain’s treatment is to enhance marketing capability and aesthetics; this is great if you desire a good-looking chain, but in order to analyze its performance, we need to observe what is happening with the chain’s internal parts.

Manufacturing Tolerances

Tighter manufacturing tolerances and a more in-depth quality control process play a large role in the price as well. All of the factors that go into this process vary by manufacturer. Usually, manufacturers discourage cross-compatibility between chain models and drivetrain models, while aftermarket chain makers encourage it.

Whether you mix brands or not is entirely up to you. Usually, 8-, 9-, 10-, and 11-speed bikes are safe to mix-and-match brands according to their needs, as long as they stick with proper cog counts (a topic that we will cover in a later section of this article). Some people even prefer to pick a chain that is one speed higher than their drivetrain for improved durability and shifting.

If you are going to mix brands, be sure to cross-check compatibility between brands and models. Certain models are completely incompatible with other brands. An example of this is SRAM’s AXS Road, which uses a chain with an oversized roller.

The hardness of the chain can factor into the longevity of your road bike too. For example, SRAM generally makes their equipment “harder,” so its chains will wear out “softer” Shimano cassettes and rings very quickly. Inversely, Shimano chains are going to wear out much faster when paired with SRAM hardware.

Another factor in crossing brand models you may want to consider is shifting performance. Experienced cyclists say that this factor makes little to no difference. Still, it is worth noting that many manufacturers specifically design their chain plate shapes to best match their own shifting ramps. Certain cyclists can tell the difference, while others do not; this will all land upon your own personal preference.

Difference between 420 chain and 40 chain

Both 420 and 40 chains have the same tensile strength and pitch, the only major difference is the width between the inner plates of #40 is larger than #420 by 1/16″.

40, 41, and 420 chains all have the same pitch (1/2″) and use the same sprocket, even though the roller width is not identical. The difference is minute and won’t cause any failure.

However, the 420 chain is more popular than the #40 chain because it is a tighter fit on most sprockets in comparison.

Difference between #41 and #420 chain

The #41 chain is not as strong as the #40 and #420 chains and will break at a much lower load in comparison to those 2 chains. It can be used with engines that produce up to 5 HP power.

The #41 chain has the same pitch and roller width as #420 but its plates are thinner and shorter, therefore, it will deform easier in comparison therefore, it is not as popular as the 40 and 420 chains.

Difference between #420 and #35 chain

Both will use a different sprocket. A #35 sprocket won’t fit a #420 sprocket and vice versa. #420 chain is 1.75 times heavier than 35 chains and can withstand nearly 2 times more load.

However, there are different variations of 35 chains like 35-1,35-2…35-5, that have more strength and weight. The 35-1 is the most easily available.

Due to the lightweight nature of the #35 chain, it is popular for racing purposes, there are certain #35 chains made for performance Go-karts such as the Gold Extreme #35 chain, which are light and can still handle powerful engines.

Another key point to note is that sprockets for the #35 chain are usually smaller than 40,41 and 420 sprockets. So you can use an axle sprocket with more teeth without having clearance issues.

You’ll also find that the clutches that use the #35 chains have 12 or 14 teeth in comparison to 10 teeth on 420 chain clutches. Therefore it’s easier to gear the go-kart/minibike high with a #35 chain.

Motorcycle Chain Sizes

What Size is a Motorcycle Chain?

As a rule of thumb, a motorcycle chain has three important dimensions, which are as follows:

  • Pitch: the spacing between the center of the pins
  • Inside width: the spacing between the two inner plates
  • Link number: How many links are in the chain

Let’s see what the most common motorcycle chain dimensions are and what the chain numbers mean!

How are Motorcycle Chains Measured?

When it comes to motorcycle chain sizes, there is a lot of confusion out there. This is mainly because there are two standards used for measuring motorcycle chains, the ANSI (American National Standards Institute) and the ISO or the British Standard.

The US-based ANSI motorcycle chains utilize inches as units of measurement and are typically labeled 25, 35, 40, 43, etc. Although ISO (British Standard) basically uses metric units, the size of motorcycle chains is often indicated in inches as well.

The most commonly used ISO motorcycle chains are as follows: 415, 420, 520, 525, 530, 530, 630.

Since the manufacturing requirements, dimensions, and load ratings of British Standard chains are slightly different, with few exceptions ISO and ANSI chains are typically not interchangeable.

What do Motorcycle Chain Numbers Mean?

Simply put, motorcycle chain numbers refer to the dimensions of the chain. The first digit in the number refers to the pitch, while the other digits are the width of the chain. The numbers used in sizing are all in eighths of an inch. Here are some examples:

  • 4XX chains: 4 x 1/8 = 4/8” pitch (often referred to as 1/2”)
  • 5XX chains: 5 x 1/8 = 5/8” pitch
  • 6XX chains: 6 x 1/8 = 6/8” pitch (often referred to as 3/4”)

The last two digits in a motorcycle chain number is the width of the chain, or to be more precise the distance between the two inner plates.

  • X20 chains: 2 x 1/8” = 2/8” inside width (often referred to as 1/4”)
  • X30 chains: 3 x 1/8” = 3/8” inside width
bike, chain, dimensions, done

If so, please don’t hesitate to check out the motorcycle chain size chart below.

For your convenience, we’ve compiled the dimensions of the most commonly used chains under one roof!

What Size is My Motorcycle Chain?

There are basically three ways to find out the chain size on your motorcycle. The easiest way is to check the current chain, as its size is typically indicated on the chain’s side. If not, you should check the owner’s manual, which typically tells you the required chain size as well as the number of links. Chances are good that your bike features a non-OEM chain, so best practice is to measure the chain.

Don’t forget that if you measure a motorcycle chain and it doesn’t match any ANSI size, it probably means that your bike has a British Standard motorcycle chain.

Besides the pitch and the inside width, you also have to know the number of links.

If you can’t find this spec in the manual, your only choice is to take a closer look at your current chain and count the links.

How do You Measure a Motorcycle Chain?

You can easily measure a motorcycle chain with a vernier caliper. Just measure the distance between the center of two pins to get the pitch, and the distance of the two inner plates to determine the inside width.

Here’s a great video on how to measure a motorcycle chain:

How do You Take Care of a Motorcycle Chain?

Taking care of a motorcycle chain typically involves four different tasks, which are as follows:

  • Inspecting (before every ride!)
  • Cleaning (300-600 miles)
  • Lubricating (300-600 miles)
  • Adjusting (as required)

Let’s take a closer look at each!

Inspecting a Motorcycle Chain

Experts and manufacturers recommend inspecting a motorcycle chain and the sprockets before every ride.

This means you should inspect the chain for any wear or damage and check its tension as well.

If you notice that the chain has too much free play or isn’t aligned perfectly you should immediately adjust it to avoid any damage.

What Should You Use to Clean a Motorcycle Chain?

According to FortNine, the best motorcycle chain cleaner is arguably iPone Chain Cleaner Spray. But you can’t go wrong by using Muc-Off chain cleaner, WD-40, or Simple Green Cleaner Degreaser. Surprisingly, many owners use kerosene for this purpose. Besides the cleaning liquid, the best tool to clean a motorcycle chain is a grunge brush.

How Often Should a Motorcycle Chain Be Lubricated?

According to Bennetts, you should lubricate a motorcycle chain every 300-600 miles. However, the recommended lubrication intervals may vary from one bike to the next. So, best practice is to check your service manual and follow the manufacturer’s recommendation.

Other factors can be the environment and/or your riding habits.

How do You Adjust the Chain Tension and Alignment on a Motorcycle?

You can adjust the chain tension and alignment on your motorcycle with rear axle adjusters. You can find these adjusters on the rear side of the swingarm (or around the shaft nut). They typically look like two bolts with nuts on them. Just loosen the rear axle nuts and set the chain tension with these adjusters. Make sure to adjust only one side at a time.

Here’s a good tutorial on how to adjust a motorcycle chain:

How Much Slack Should Be in a Motorcycle Chain?

As reported by Cycle World, the typical motorcycle chain slack for dirt bikes is 1.4 – 2.0 inches while for street bikes it is 1.2 – 1.6 inches. However, the recommended chain slack, just like the correct measuring method is always clearly stated in the service manual. Don’t forget to check it before you do any maintenance on your chain!

How do I Make Sure my Motorcycle Chain is Straight?

To make sure your motorcycle chain is straight you should move directly behind the rear sprocket. Lift the chain on the bottom to make it completely tight. Check the top of the chain from the rear sprocket. If it’s adjusted correctly, the chain should look completely straight.

Don’t forget that when you adjust the rear wheel, you actually adjust the rear sprocket as well, which affects chain alignment.

So, to get a completely straight chain, you have to make sure that the rear wheel is completely aligned.

bike, chain, dimensions, done

For your convenience, some bikes feature reference marks on the swingarm. When you adjust the rear wheel, make sure they match on both sides!

FAQs About Motorcycle Chains

As a takeaway, let’s look at the most common questions about motorcycle chains!

Do motorcycle chains need lube?

Yes, every motorcycle chain requires lubrication, even the sealed chains.

What happens if you don’t lube your motorcycle chain?

If you don’t lube your chain, it will wear out much faster. What’s more, the lack of lubrication can also shorten the lifespan of the sprockets.

Can I use a degreaser on a motorcycle chain?

Yes, according to MC online, you can use a degreaser on a motorcycle chain without any issues.

Can I use WD-40 on a motorcycle chain?

Yes, WD-40 can be used on a motorcycle chain, but don’t forget that WD-40 is a cleaner and not a lubricant!

Can I use engine oil to lubricate a motorcycle chain?

How To Replace A Mountain Bike Chain | Change Your Chain Like A Pro

No, using engine oil to lubricate a motorcycle chain is definitely not recommended. Engine oil doesn’t lubricate the chain properly and is prone to attracting much more dirt. This results in more maintenance and a shorter chain life.

Special motorcycle chain lubricants and grease are typically much stickier than engine oil, so they last much longer and lube the chain properly.

What is an O-ring chain on a motorcycle?

The O-ring that motorcycle chains feature are little rubber seals (O-rings) between the outer and inner plates. These seals are designed to keep the grease inside the inner components of the chain.

Do O-ring chains need lube?

Yes, contrary to popular belief, O-ring motorcycle chains need to be lubed. Why? This is because lubrication is needed between the chain and the sprockets, and it can also help protect the chain from rust.

How do you maintain an O-ring chain?

To maintain an O-ring chain, you have to occasionally clean and lubricate it. Since the lubricant on these chains is primarily used for rust prevention, you need to use less of it.

Do you need to lube X-ring chains?

Yes, X-ring chains have to be lubed occasionally.

What is the ANSI standard for chains and sprockets?

The most common ANSI standard motorcycle chain sizes are as follows: 25,35,40,41,50.

What’s the difference between a 520 and 530 chains?

The inner width of a 520 chain is 1/4″, while the 530 chain is 3/8”. The pitch of both chains is 5/8”.

What’s the difference between 520 and 525 chains?

The inner width of a 520 chain is 1/4″, while the 525 chain is 5/16”. The pitch of both chains is 5/8”.

What is the difference between 420 and 428 chains?

The inner width of a 420 chain is 1/4″, while the 428 chain is 5/16”. The pitch of both chains is 1/2”.

Why Chain Length Matters & How To Get It Right | Maintenance Monday

Can I use a 520 sprocket with a 525 chain?

No, you can’t use a 520 sprocket with a 525 chain, as this sprocket is too wide for a 525 chain! (4/16” vs. 5/16”).

What does 530 mean on a chain?

The number “530” on a chain means that the pitch of the chain is 5/8”, while the inner width is 3/8”.

What does 420 mean on a chain?

The number “420” on a chain means that the pitch of the chain is 1/2”, while the inner width is 1/4”.

What is a 415 chain?

The number “415” on a chain means that the pitch of the chain is 1/2”, while the inner width is 3/16”.

What is the pitch of a 520 chain?

The chain pitch of a 520 chain is 5/8”.

Will a 40 chain fit 420 sprocket?

No, unfortunately a 420 sprocket with a 40 chain doesn’t match.

Is a 50 chain the same as 520?

No, the inner width of the 50 chain is 3/8”, while the 520 chain is 1/4″.

Is a 420 chain the same as a 35?

No, because 420 and 53 chains feature different dimensions.

What is the strongest motorcycle chain?

The strongest motorcycle chain is arguably the 630 chain with a tensile of about 10,000-11,000 lbs. This is why 630 chains are commonly used on drag bikes. Regarding ‘regular’ sizes, 520 and 530 are also very strong.

Are gold motorcycle chains better?

Gold motorcycle chains can give a custom look to your bike, and there are rumors that they are less prone to rust. Beyond these, it seems there is not much difference between gold and regular chains.

What direction does a master link clip go on?

The closed end of the master link clip must always face the direction of rotation.

How much does it cost to tighten a motorcycle chain?

As a rule of thumb, tightening a motorcycle chain typically costs about 20-60. In most cases this price includes the cleaning and lubing as well.

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