Where to Get a Pin for Your Bike Trailer Hitch Coupler

That little security pin for your bike trailer that keeps getting lost just might save a life!

The security pin is a small metal contraption that secures the arm of the bike trailer to the coupler attachment on the bike. It ensures that the trailer does not detach from the bike while riding.

The security pin is also referred to as a retaining pin, safety pin, hitch pin, or coupler pin.

The bottomline—it’s an important piece of the bike trailer.

But where can you get one?

I have lost mine several times on different brands of bike trailers, so I know exactly what it’s like and where to get the right replacement.

If you’ve lost your pin or you’re not sure which is the correct pin for your specific trailer, here’s how to get a replacement.

A bike trailer security pin can be purchased for less than $10 online from Amazon. All of the major bike trailer manufacturers use the same standard security pin, including trailers by Burley, Schwinn, Instep, and Hamax. Thule bike trailers, however, use a unique security pin.

You can get two security pins for around $11 from Amazon here.

That particular product also comes with two Burley couplers, which you can ignore if you don’t have a Burley trailer. It’s just much cheaper to buy two pins that come with the couplers. Regardless, I recommend getting two pins just in case you ever need another.

If you’re also looking for a coupler attachment for your bike trailer, check out the guide I put together on couplers.

Does the size of the security pin matter?

All of the major bike trailer manufacturers use the same size for their security pins, including bike trailers by Burley, Schwinn, Instep, and Hamax.

Thule is the only major bike trailer brand that uses a different security pin system, which I’ll outline below.

Thule’s unique security pin

Thule is the only notable manufacturer that uses a unique attachment system that requires a different pin. Unfortunately, their pin is sold together with the entire hitch arm, which can be found on Amazon here.

Can you use a standard security pin on a Thule bike trailer?

Thule bike trailers come with a unique “Hitch Lock Pin” that acts as the security system to keep the trailer from detaching. Thule is the only brand that does not use the standard security pin that other brands use.

If you need a new security pin for a Thule bike trailer, you will need to purchase an entirely new hitch arm, which comes with the pin attached to the arm.

That’s an expensive pin!

Do you even need the security pin?

The coupler security pin is designed as a safety mechanism to ensure that the trailer arm does not detach from the bike’s rear wheel while riding. Therefore, it is very dangerous to attach a bike trailer without a security pin. It is crucial to have the proper security pin for your bike trailer’s coupler system.

Some bike trailer owners attempt to DIY their coupler attachment by designing their own contraption to secure the bike trailer. Unless you are a very skilled and knowledgeable welder, I strongly recommend against that and just spending the $8 to get a new security pin. It’s worth the investment!

There are a few individuals on YouTube who have showcased their welding skills by manufacturing their own coupler attachment system for their bike trailer. I imagine it’s a rewarding project to take upon yourself, but I wouldn’t recommend trying that.

You can check out one of the DIY bike trailer videos here.

Are bike trailer pins different from car trailer pins?

Bike trailer security pins should not be confused with car trailer pins. Car trailers use many different lengths and diameters of pins that will not work on bike trailers. They do not offer the same convenience and function as a bike trailer security pin.

I recommend just purchasing a couple of pins on Amazon for just $8 that are specifically designed for bike trailers.


A bike trailer’s security pin is the most easily misplaced accessory. And it’s probably one of the most important pieces that come with the trailer.

If you’re in need of a new security pin (or a few), then be sure to check out this option from Amazon for less than $10. If you happen to have a Thule bike trailer, then you’ll need to get a replacement hitch arm, which you can also get from Amazon here.

Need help finding the right bike trailer?

If you need help finding the right bike trailer for you, my recommended trailer for most people is the Swhinn Joyrider, which is an affordable double-seater that converts beautifully to a stroller. Check out my full review with photos here.

Check out the Ultimate Guide to Buying a Bike Trailer for more help with choosing a trailer. I also have compiled a list of the top bike trailers for every common situation, which you can check out here.

Ride on!

Benjy Suzaki

Hi, I'm Benjy Suzaki and I love cycling with my kids. Biking has been a big part of our family life ever since I decided to bike everywhere instead of drive, including to my job in NYC from New Jersey. BikeTrailerPlanet.com is all about how to make biking a priority in your daily life through bike commuting, bike maintenance, and riding with kids.

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