Delta - Installation

Uncut Delta

Delta Topper

Delta Decals + Adhesives

Uncut (left)vs. finished (right)

Before purchasing or installing Delta, please ensure if meets all compatibility requirements. Your setup must meet ALL of the compatibility criteria in order to work with Delta. If you have any questions about compatibility with Delta, please contact us before purchasing. Due to the trim-to-size nature of the product, we do not accept returns for Delta.


Installation of Delta is relatively straightforward, but does require some time and care. Because Delta is a trim-to-size product, it is important to make sure your measurements are accurate before committing to a cut. As the maxim goes, "measure twice, cut once."


Bars off, test fit with tape

Align Delta with Brake

Align decals

Use silver pen to mark cut line

  • The first step to measuring where to trim Delta is to properly set up your front end.
    • When using with Alpha One, Delta should be trimmed to match the lowest element in your stack, whether it is the bar itself, or an aero spacer.
    • When using with Alpha X , switch any aero-matched stem spacers for round spacers, and trim the Delta to mate with the bottom surface of the Alpha X X itself. Delta will cover the round spacers and mate directly with the stem, for the best aesthetic and aerodynamic performance.
  • Begin by removing your stem/handlebars. There is no need to disconnect any cables; the handlebar may be left hanging to the side, as when packing the bike to travel.
  • Delta has an interior curved tire shield surface that should line up with the same arc on your Omega brake, or with the upper surface of your fork. Remove the Omega X brake cover for use with Delta. Temporarily affix it to the bike with electrical tape as shown in the images above.
  • Delta comes with two removable cutting guide decals, one for the drive side and one for the non-drive side of the Delta. Carefully align each decal, starting from the rear edge, with the line you will cut aligned with the bottom edge of the decal. This should align with the lowest aero-matched element of your setup, whether that is an Alpha One base bar, Alpha One aero spacer, or Alpha X base bar.
  • Once the decals are in place, use the supplied silver paint pen to mark the line to be cut, on both sides. Once finished, remove the Delta from the bike, and remove the decals from the Delta, leaving only the silver line. You can now reassemble your handlebars onto the bike.


Cut with rotary tool

Clean burrs with sandpaper

Test fit Topper

Test fit to bike

  • Cut carefully along the cutting guide, using a handheld saw or rotary tool with a cutoff wheel.
  • Note that when cutting, some of the plastic at the cutting area will pill or melt into small burrs. After all cutting is complete, clean any burrs or rough edges with sandpaper or a hand file. The edge does not need to be perfect, as it will be covered by the Topper.
  • Once the cut edge is finished and cleaned, test-fit the Topper onto the Delta, and test fit the complete assembly onto the bike.

Final Installation:

3m Adhesive Strips

Peel backing, install

Peel front, expose adhesive

Install Topper, front first

L-Shaped strips

Final installation

Aero perfection

Flawless front-end!

  • The next step is to permanently affix the Topper to the Delta. There are two for the drive-side and two for the non-drive side. You should only need one per side. Match the decals to the appropriate side, peel off the backing, and affix to the cover. Peel off the front 3M logo to expose the adhesive, and finally install the topper, front first, onto the cover.
  • The Topper has three threaded holes on top, for inserting set screws which will act as retention pins. These mimic the retention pins on the aero-matched spacers of Alpha One, or Alpha X. If you are mating Delta to an Alpha One, fill the two outer holes with the set screws, leaving the center hole empty. If you are mating Delta to an Alpha X, only fill the center hole, leaving the outer holes empty.
  • When installed onto the bicycle, Delta's upper surface should match perfectly with the Alpha One or Alpha X above it. The rear edge of Delta should run parallel to the steering axis of the bike. Ensure proper alignment, then use the included L-shaped adhesive straps to secure the lower legs of Delta onto the bike fork.
  • Enjoy the ride!

Fit Guide

This Guide shows you how to set up your TriRig Omni with the TriRig Alpha One or Alpha X aerobars. This Guide can help you replicate your current bike position, or set up your bike based on numbers from a bike fitter. The Fit Chart below shows the actual X/Y coordinates of your arm pads measured from the bottom bracket. This coordinate is the most important number that bike fitters use to determine your position on a triathlon bike. Be aware that some fitters use a coordinate to the top/back of the pad, rather than the top/center. In that case, you can subtract 44mm from all of the reach numbers in the Fit Chart, which yields the back of pad number. The steps below provide an easy-to-follow system for making sure you have the perfect fit with your Omni.

Step 1: Determine your current fit numbers

What we want is the X/Y coordinate to the top/center of your aerobar pads, measured from the bottom bracket. Most bike fitters can provide this number to you when performing a bike fit (although some provide it to the top/back of the pads rather than top/center). If you already know these numbers, you can skip this step. Otherwise, follow the steps below to determine these numbers for your current bike setup:

1-Place your bicycle up against the corner of a room, with the back tire abutting the wall.

2-Next, measure the vertical distance from the floor to the center of the bottom bracket. We'll call this measurement Floor Offset (FO).

3-Measure the horizontal distance from the wall to the center of the bottom bracket, we'll call this measurement Wall Offset (WO).

4-Measure the vertical distance from the floor to the top of your aerobar pads. This measurement will be Pads-To-Floor (PTF).

5-Measure the horizontal distance from the wall to the center of your aerobar pads. This will be called Pads-To-Wall (PTW).

6-Subtract Floor Offset from Pads-To-Floor (PTF minus FO). This is your Pad Stack.

7-Subtract Wall Offset from Pads-To-Wall (PTW minus WO). This is your Pad Reach.

Step 2: Review Frame Geometry

Small Medium Large
Frame Stack
(BB to Headset)
490mm 525mm 560mm
Frame Reach
(BB to Headset)
375mm 405mm 435mm
Front Center 560mm 600mm 640mm
Rear Center 400mm 400mm 400mm
Seat Angle 79° 79° 79°
Head Angle 72.5° 72.5° 72.5°
Fork Offset 48mm 48mm 48mm

Step 3: Select Size, then find your position on the chart

The chart below shows the stack and reach information for the TriRig Omni with the included Alpha X aerobar, complete with the number of extension spacers and stem spacers used for each setup. Here's how to use the chart:

1-Use the dropdown box in the upper-right corner of the chart to select a bike size.

2-Find your Stack in the left-hand column of the chart, or the row that most closely matches your stack. Every cell in this row represents a way to set up the Alpha X on your Omni that will produce this stack number.

3-Each cell states the amount of Pad Spacers as well as Stem Spacers to use in order to hit your stack number.

4-In most cases, there will be multiple cells that can hit your stack. The best setup for your position will generally be the one with additional colored cells above AND below your selected cell. These cells represent room to move up or down in the future, merely by adding or removing Pad Spacers, which is generally the easiest way to make a position change.

5-Cells in blue represent a standard setup with the extensions over the bar. Cells in green represent the special undermount position, where the extensions are mounted below the bar.

6-Once you have selected a cell from your Stack row that represents your preferred position, look at the bottom of that column to the Reach section. The three rows of Reach cells show the reach to the center of the pad based on the three different adjustment positions available on the Alpha X arm cups. Select the one that most closely matches your Pad Reach number, and set up your pads/cups accordingly.

7-Note that fit numbers for the Omni w/ Alpha X are measured from the top/center of the headset to the top/center of the pad. All measurements for overmount hardware include the integrated BTA mount.