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The InterLock™ hides inside of your bike frame through the seat post. It's universal and can be installed on virtually any bike.
1,112 backers pledged $51,213 to help bring this project to life.

Seat Post Sizes!


Hello again everybody!

One point to clarify - by default, we will be sending out 27.2mm size seat posts. If that's the correct size for you, ignore this message!

We do in fact have three sizes available for seat post diameters. 25.4mm, 27.2mm, and 31.6mm. The 31.6 units we will ship will in fact be 27.2mm with a 31.6mm shim. We've done this because it's a very common size.

To check your seat post size, pull out your existing seatpost and look on it for the writing or stamping to see what the size is, like the photo below. Or just check online to see if there's info about your bike with what the seat post size is.

If your seat post is 25.4 or 31.6mm, send us an email to with the info and we'll add it to your account. These other sizes are the ones that we're having completed in the second half of the production run, coming in January.

If your seat post is a size other than these three, you'll need to buy a shim for a couple of bucks from your local bike shop. I'm sorry that we can't accomodate everyone, but there is a pretty wide variety of sizes that pop up and it's not manageable for us to get everyone covered. So if you have a size like 28.6mm, or 31.8mm, I suggest you get the standard one we're shipping of 27.2mm and call up your local bike shop to grab a shim, or order one from online if that's easier.

Please don't message us on Kickstarter with your sizing - send it to :)

Happy Seatposting!!


Pull out your old seatpost and check the bottom of it for what the sizing is that you need!
Pull out your old seatpost and check the bottom of it for what the sizing is that you need!


    1. Creator El Drijver on November 25, 2013

      Great service!

    2. Creator Greg Barnett on November 25, 2013

      Wow Adrian, I never even thought about the seat post will look tonight!