Terracycle Universal Boom Adjust Chain Tensioner

The Universal Boom Adjust Chain Tensioner allows you to move your boom without hassling with the chain. It automatically compensates for changes in chain length when you adjust the seat for different riders. Perfect for anyone that would like to share their trike with different riders. The installation is simple, the design is sleek and the materials are strong. If more than one person rides your trike, then a Universal Boom Adjust Chain Tensioner is perfect to eliminate the worries of whether the chain is too long or too short! We make the mounting clamps in a wide range of sizes, so let us know your trike/bike make and model, we’ll figure it out from there.

Key Features

• We originally designed the idea at the request of Catrike. They wanted something for dealers to be able to easily offer test rides without having to lengthen or shorten the chain. It was such a hit that it became clear it wasn’t really just an internal Catrike item for dealers, and that it wasn’t just an item for Catrikes!
• One of the requirements was that it would handle the full range of boom adjustment. We originally designed something with a derailleur, but it wasn’t possible to get the needed range. So, we went for it and made this. Ball-bearing idlers, custom machined clamps, the works. The response has been overwhelming, it has been hard to keep them in stock at times.
• All parts are black anodized CNC machined 6061 T6 Aluminum. All fasteners are stainless steel. The idlers are Delrin with 6mm sealed cartridge bearings.
• The front clamp comes in a crazy variety of sizes, machined specifically for boom tubes, which are sometimes odd sizes. The rear clamp comes in every known main tube size from 36mm up to 60mm, from 1.5 into 2.0in. The lengths of the arms are designed to cover the full range of boom adjustment.
• No particular maintenance is required. The idlers are high quality and have sealed cartridge ball bearings that will outlast the other parts of your drivetrain by several times.
• Available Clamp Sizes: 36mm, 54.2mm, 55mm, 60mm, 1.5in, 1.625in, 1.75in, 1.8in, 1.847in, 1.885in, 2.0in, Greenspeed Anura rectangular tubing, Greenspeed GT20 rectangular tubing, Greenspeed Magnum rectangular tubing, Terratrike Rover rectangular tubing…
• The clamps and arms are used in pairs, one on the main tube with the arm pointed forward and one on the boom with the arm pointed backwards. Here are the typical combinations:
  • 60mm + 54.2mm = HPVT, Azub, GS Magnum, AL Actionbent
  • 2″ + 1.885″ = TiTrikes, steel Actionbent
  • 2″ + 1.847″ = Trident
  • Florida Arm + 1.8″ = Catrike
  • 1.75″ + 1.625″ = ICE, non Magnum Greenspeed, Edge
  • 1.75″ + 1.5″ = TT Rambler, steel TW Bents
• Normally, the front clamp is positioned just behind the chainrings, with the front arm spaced out away from the clamp, while the rear arm is flat right on the rear clamp. On the Azub trikes, the main tube is long and the boom tube is short. The boom inserts into the main tube almost up to the BB shell. On the Azub, the arm spacer is moved to the rear so the front clamp can go all the way up by the BB. Since the arms are now swapped inside for outside, the idlers need to be swapped inside to outside also. If you let us know you have an Azub, we do this for you.
• This kit is designed to fit on almost any trike on the market. That’s why we call it the Universal Chain Tensioner! Just let us know the make and model of bike or trike that you have, and we’ll make sure you get the right-sized CNC machined mounting clamps.
• Also known as a Chain Gobbler