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Goal: Determine the birth year of a bicycle.  

Tips for Determining the Birth Year of a Bicycle  

Examine the Stickers/Labels on the Frame 

The frame is the heart of a bicycle.  When people ask “when was my bike made”, they’re actually asking “when was my frame made” because every other component can be replaced.

Most bike manufacturers are actually frame manufacturers. They build frames and then equip them with components produced by other companies (e.g., Shimano, SRAM…etc.).  

Consequently, one first has to examine the frame. Look for stickers/labels. If the frame hasn’t been repainted, chances are that you will find at least a partial label on it. Most of the time, manufacturers put the name of the company and the frame model on the tubes.  

If that information is present, you can just put “manufacturers +bike model” in a search engine and check the information.  

A while back I purchased a second-hand retro road bike. Before the purchase, I found the era when the bike was produced.

The producer is Centurion and the bike model is “Futura”. I immediately discovered information about the company and figured out that the model was made in the late 80s.  

If the bike is fairly recent and from a brand with a decent online presence, you will have an easier time finding the production period.  

That said, a brand and model name are not enough to find the exact year because a company could make the same frame for years.  

To find the exact year, you can do the following:  

1. Copy the serial number of the frame (it’s under the bottom bracket shell) 

2. Contact the frame manufacturer and give them the serial number.  

From it, they should be able to tell the frame’s birthdate.  

No Data Available 

If the bike has been repainted or its decals have been removed, then the task becomes increasingly difficult.  

The first option is to get the serial number and look it up in an online index.  

If the search doesn’t yield acceptable results, the next step is to search for bicycle components that could indicate a time period.  

For example, if the bike has mounts for downtube shifters, then the youngest it could be are the 1990s.  

Frame material  

If the bike is made of steel, chances are that it’s fairly old. Of course, modern steel bikes are being produced as we speak, but the quantities are small in comparison to aluminum and carbon bikes.  

Frame details 

If the bike is made of steel and brazed, it’s either a custom job or quite old (e.g., the 70s). Brazing is a simpler and cheaper method to connect bike tubes and was used before TIG welding. However, since welding is more efficient, eventually it took off.

If the frame is brazed, the transitions between the tubes will be seamless. If it’s welded, you will easily see the welding seam.  

If unsure, you can sand a point where the tubes meet. If they’re brazed, you will notice the yellow bronze underneath.  

If the bicycle is made of carbon, chances are that it’s fairly new. That said, carbon bikes have been produced for decades. 

Examine The Most Difficult Components to Replace 

If you try to source the age of a bicycle by examining its components, you could go in the wrong direction because those can be replaced. 

For example, I replaced the cranks and chainrings of my Centurion Futura with a set from an even older bicycle from the 70s.

That’s why it’s recommended to start with components that are the most difficult to replace.

• Rims 

It’s not super difficult to replace a rim, but it’s still a process that the average casual cyclist doesn’t want to deal with.  

If the rims of the bicycle look original, they could help with the identification process.

Rims from a somewhat reputable brand will have a name on them. You can use it as a keyword to find out more.  

Of course, it’s possible that the wheels have been replaced. Ignore the tires (unless they’re really old) as they are a frequently changed component. Ditto for the inner tubes.  

• Brakes and Brake Levers 

The brake system can also reveal a lot about a bike. For example, if you have a bicycle with cantilever brakes, the rear part of the frame will have a hanger. This detail indicates that the frame has been made specifically for cantilever brakes.  

Cantilever brakes indicate the late 80s or early 90s. If the bike has V-brakes, it’s probably from the mid or late 90s. If the bike has disc brakes, it’s even younger.  

In short, the brake chronology for MTBs and commuters is as follows – cantilevers – V-brakes – mechanical disc brakes – hydraulic disc brakes. 

Road bikes are a bit different as even modern models continue to rely on caliper brakes, although disc brakes have a growing market share.  

That said, there’s a clear difference between older and newer calipers. The older models are single-pivot whereas most modern ones are dual-pivot. Additionally, an older caliper will be a lot less shiny than a new one.

If the bike is really old, chances are that the manufacturer of the caliper is either not as popular anymore or out of the business.  

Transmission and Shifters 

The number of gears and the shifter type tell a story too. The fewer the speeds, the older the bike. For example, road bikes from the 70s had around 5 speeds (5 rear cogs) whereas as road bikes from the 80s and early 90s were equipped with 7 speeds. Newer road bikes have 9-12 rear cogs.  

The shifting style is important too. Road and touring bikes from the 70s and before have friction shifters. Friction shifters move as much as the rider wants them to and are completely absent from newer bikes because they’re more difficult to use.  

Road bikes from the late 80s and early 90s, however, have one friction shifter at best (for the chainrings) and one index shifter for the gears at the back.  

Index shifters move a predetermined amount of cable and make a click. They don’t require much thinking as long as the gears are indexed properly. One click results in an instant down or upshift.  

Freewheel or Cassette 

It’s also worth analyzing whether the bike has a freewheel or a cassette.

The freewheel is older and contains the ratcheting mechanism allowing the rider to coast. If the bike has a cassette, however, it’s relying on a freehub to coast.  

If the bike has a freehub, the oldest that it can be is late 80s. If the bike has a freewheel, however, its age could vary greatly because some modern entry-level bikes also have freewheels.  

In that case, the number of speeds could reveal a lot. Older freewheels have 5 or fewer cogs/speeds whereas newer ones (the late 80s and beyond) come with 7-8 speeds.  

Freehubs

The freehub model and brand could else reveal the origin of the bike.

Examples:

• High-end 9-speed Shimano freehubs became available in the late 90s. Thus, if the bike has a 9-speed Shimano hub, it was produced in 1997 or later.

• Shimano’s 10 and 11-speed hubs came in 2004 and 2012 respectively.

• Shimano’s 12-speed hubs came in 2020.

• SRAM road hubs came in the 2000s.

• Until 1996, Campagnolo hubs were limited to 8 speeds too.

Cranks 

The cranks of the bike are also fairly difficult to replace and can last a long time, especially if the chainrings are removable. Thus, it’s worth examining them. 

If the cranks are designed for a bottom bracket with external bearings, then the bike is relatively new, or at the very least, it has been upgraded.  

If the cranks attach to a square taper bottom bracket, however, it’s difficult to guess the age of the bike because square tape bottom brackets have been used for decades.

That said, if the cranks are cottered (secured to the bottom bracket via a pin), then one can conclude that the bike is made before the 1970s.

Since cottered cranks are a bit tricky to remove and mount, it’s unlikely that the user has installed them for style points. The rest of the bike will more than likely reflect the same era.

Frame Dropouts

The dropouts of the frame (the part of the frame to which the rear wheel connects) are also indicative of the frame’s age.

If the dropouts are forward-facing and fairly long, then the bike frame was made in the 1970s or before.

If the dropouts are forward-facing but shorter, then the frame is made in the 1980s or later.

If the dropouts are vertical, then the frame is even younger.

Of course, this doesn’t apply to track frames as they always come with rear-facing/horizontal dropouts.

Frame O.L.D.

The term O.L.D. stands for over-the-locknut-dimension and refers to the usable distance between the two locknuts of the rear hub.

The spacing of the frame’s rear dropouts has to take into consideration the O.L.D. of the hub or else the wheel won’t fit properly. Since more gears require a wider hub, the O.L.D. that the frame is designed for is indicative of age two.

FAQ: Can’t I just ask the seller?

Theoretically, if the seller is the original owner or has inherited the bike, they may know the biography of the particular unit. However, the seller may also change some of the facts to facilitate the sale.

For example, if the bike is from the 70s, the seller may make it younger to preserve the deal.

To avoid similar problems, you can do your own research beforehand by simply analyzing the photos.