The Sprigner comes with inserts so that it can be used on most bicycle's tubes.
The rest of the Springer ATTACHES to the base via a bolt that goes through the springer. This Bolt, does NOT go completely Though the hole for it in the base. The bolt head STOPS the bolt so that only a piece of it is on each side. Then you attach the rest of the Sprigner to the Bolt, and secure the two parts with a locking pin. This permits rapid removal of the Springer when not needed (Through the base stays on the bike).
Picture of the permanent part:
The "bolt" going through the base:
Picture of the base with the "bolt" attached:
Picture of the rest of the springer attaching to the "bolt":
I obtain these Drawing from the Springer web site on how to assemble the Springer:
http://www.springerusa.com/assembly.htmlOne side note: The Sprigner is shaped so that it clears YOUR feet as you Pedal the Bike (When mounting the Sprigner you have to make sure, which is easy). The Springer starts its U AFTER it has cleared the area where your feet MAY go as you Peddle. You have to make sure you mount the Springer high enough on your bike so your feet are NOT block by it when you Peddle. This is NOT a problem for me for I put the Sprigner in the Seat Post, for I have a LONG seat post. If you do NOT have a long Seat post, then you have to mount it on the Seat Tube, which can lead to the Sprigner Blocking your feet, if mounted to low on the tube (Another reason NOT to mount it on the Seat Tube is you have small dogs, the seat tube may put the Sprigner TO HIGH for small dogs). I have used the Sprigner on Mid-size dogs and it worked (When she wanted to run which is NOT always the case).