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Handlebar Mast

2 reviews
SKU: GMH104.4
Short 75mm

We have run out of stock for this item.

An important part of the T-Cycle fully adjustable steering system is the lightweight Handlebar Mast with adjustable stem for your handlebars. With our choices of mast and stem combinations, you'll never again be limited by the stock position offered by most manufacturers. Also included with the mast are two adjustable cable guides for your brakes and derailleurs—no more zip ties or funky Velcro fasteners! This will enable you to properly locate your cables for a precise and effective operation. Get the custom setup you want for the bike you love!


1. How does this work?

The mast itself is a 1-1/8 in (28.6mm) diameter aluminum tube. It is slotted at the bottom to clamp onto a 1 in (25.4mm) diameter fork steerer or 1 in stem. At the top, a standard 1-1/8 in threadless stem clamp on to hold the handlebars. Custom made clamp on cable guides keep your cabling neat. Since everything clamps on, you can move everything around and adjust things to wherever you like them.

2. Can I use a different stem at the top?

Yes,f you ever want to use a different stem, it's easy to change it.

3. Can I turn the stem around and have it face forward?

Yes, no problem. That's the beauty of this system- everything clamps on, so you're free to move things around wherever you want them.

4. Can I shorten the mast? How hard would it be to do that?

You can shorten the mast with a hacksaw or tubing cutter. The top cap is easily removed and put back on. If you use a hacksaw, we recommend wrapping tape around the edge of where you want to cut to help guide the saw. File the top flat, put the cap back on, and you're good to go.


Setup is straightforward. Pretty much everything can be adjusted, so you are free to do things lots of ways.

It is generally easiest if you attach the mast to your fork steerer or stem first, then mount the handlebars. From there, adjust things until the handlebars are in the right place. To move the top stem, it may be easiest to remove the pinch bolts and reinsert one from the other side. Put a coin in the slot and tighten the bolt so it pushes the coin against the other side of the slot to open it. This will make the stem easy to move around. When you get it where you think you want it, loosen the bolt and let the stem grip again. When you're satisfied with the final position, put the bolts back where they were and tighten them down.

To route the cables, temporarily remove the mast, the lower clamp, and the cable guides. Remove the clamp bolts from the cable guides to open the pinch slot. Slip the cable housing through the open pinch slot in the cable guides, and arrange the cable housing in the tunnels. Slide the guides up the mast and reinstall the clamp bolts. Position the guides for the best drape and routing of the cables, then tighten them down.


  • This mast system was designed for versatility and adjustability. If your present mast isn't quite what you want, this mast system is a good way to create just what you need.
  • We make the 20 inch masts so people that know they need a tall mast, but are unsure of how tall, can trim off any extra length after they've dialed things in.
  • The top stem adds a little height. The short stem adds about 3/4 inch, the long stem adds about 1-1/4 inch.
  • The cable guides can also be ordered separately.
  • Mast tube is 1-1/8 x 0.058in 6061 T6 seamless drawn aluminum. It is slotted at the bottom and powder coated black.
  • The lower steerer/stem clamp is a 2 bolt clamp. The top stem is a standard 1-1/8 inch threadless stem. It has a 25.4mm (1 inch) handlebar clamp.
  • We recommend the fork steerer or stem at the bottom be inserted at least 1.8 inches (46mm) inside the mast to ensure a good mechanical connection. The slot in the mast is designed to face back towards the rider. This mast is designed to clamp to 1 inch diameter smooth fork steerers or folding/hinged stems. It is not designed to clamp directly to a threaded stem. If you have a threaded stem, a Threaded to Threadless Adapter is required. If you are clamping to a threadless fork steerer, you will need some way of preloading the bearings, like a clamp on bearing adjuster.
  • The clamp on cable guides have tunnels for four standard sized cable housings and one computer wire. With today's modern housings, it's better to go all the way from the controls to the frame stop, or even all the way to the brakes or derailleurs, without stopping. The guides can be moved up and down and to the front or the back depending on how your cable routing works best.
  • If you ever shorten your mast, the easy way to get the top cap out is to tip the mast over, drop a screwdriver in handle side down, and shake the mast up and down. The screwdriver will pop the cap out from the inside without marking.
  • This mast system is compatible with a wide range of bikes. As long as the fork steerer or lower stem is 1 inch, you can use this mast. If you have a threaded fork, you will need a Threaded to Threadless Adapter. If you have a threaded fork, you may need a bearing adjuster. We supply a top stem with a 1 inch handlebar clamp. This can be shimmed to 7/8 inch if you have 7/8 inch bars. T-Cycle handlebars come with shims to go from 7/8 inch to 1 inch.
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James H.
United States United States


Service and quality product!

Elliott D.
United States United States

Handlebar Mast

Item description was confusing but parts could be selected to work.