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​How to Select a Size


The US Flyer has two basic sizing options; size of the seat post shaft, and weight of the user. First, measure your existing seat post, or the opening in the frame where the post will go. On most bikes over 20", the post is around 1" while 20" bikes are usually 7/8". These are the two options offered in size, and shims are included to allow adjustment for a tighter fit.

The second option is weight class, which falls into four categories given as options on the Sales page of each product (Up to 90lbs, 91-150lbs, 151-199lbs, 200lbs and Up). Simply select the category you fall under.  

My bike doesn't have exactly 7/8" or 1" post, can I still use the US Flyer?

We have included a Shim Adapter Kit with each US Flyer, which will help you get a tight fit between the post opening and the US Flyer. The 7/8" model will fit 22-25mm openings (up to 1"), and the 1" model will fit 25-31mm openings (up to 1 7/32"). Also, please be careful with the shims. By their nature, they are constructed of thin, sharp metal. The included black rubber band is used to cover the exposed edges where they rest on the bike frame.

One of the shims has red paint on the top. Why is that?

The thinner shim has red paint on top to help it stand out from the others. This is just to make it easier to tell the difference between them. And remember, all of the shims are sharp, so exercise caution when handling them.

The US Flyer is installed, but it is rotating in the bike/ sinking into the bike when I sit on it

Please make sure the US Flyer fits tightly in the frame opening, use the included shims if necessary. Next, tighten the bolt on the bike frame until the US Flyer cannot move in place. The frame opening is designed to close slightly, but not enough to hold an un-shimmed seat post in place.


What if I want to disengage the shock feature?


To disengage the shock feature of the US Flyer, or to make a quick seat height adjustment, turn the black knob located underneath the colored bellow clockwise until tight. This can be done at full height, or compress the spring to desired height and tighten. More details are available in the included Instructions. 

What is the Minimum and Maximum Height?

 For both models, the minimum height is 4". On 7/8" (20" Bike), maximum height is 7", and 1" (20" or Larger Bike) maximum height is 9". On either model, a minimum of 3" of the US Flyer shaft must be installed in the frame; don't worry, this is marked as the "Max Height Line" on the US Flyer and is noted in the instructions.

What's included with my purchase?


The picture on the About page shows everything included, but listed:

  • US Flyer Seat Post

  • Adapter Shims (4)

  • Printed Installation Instructions

If anything is missing when you receive your unit, please contact us immediately

NEW! We are beginning to include a helper spring starting Spring 2021! This spring can be added to the main spring to increase the firmness of the ride. Please view the video HERE (will open video in new window) for instructions on how to install, and we will also be adding step-by-step photo instructions in print and on the site in the near future. As always, reach out to us if you have any concerns or issues!

Do I need anything else?

You'll be removing your existing seat and post, and reinstalling the seat on the US Flyer, so you will need the proper wrench (not included). You may also need a Seat Clamp, if your current post is not equipped with one; these are available at most bike stores for around $3.

Shipping, Returns, and Warranty

Select your preferred ship speed, and we'll handle the rest! We try to ship out as quickly as possible, but give us 1-3 Business Days; we'll contact you by email to confirm the order has been shipped, and provide the tracking information if we have it.

If for any reason you are not satisfied with the US Flyer, please Contact Us so we can resolve the issue. Be it a return, repair, or exchange, we want our customers to be happy. If for some reason we ship the wrong size product, or a product is defective,we will cover the return shipping and ship back the correct one. For mistakes on the buyer's end, we ask you to pay the shipping.

One Year Workmanship Guarantee

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