Endless Arc | Arc ES Setup Guide

This guide explains how to properly mount and align your new Endless Arc or Arc ES frames to you boot, and how to configure the 2-piece axles using either 80 or 84 mm wheels.


Frame Mounting

UFS (Flat Mount)

The short slots in the frame allow for a centered mount at one end, and up to 3 mm of rear bias at the other. This adjustment range allows you to optimize the location of the middle pivot points relative to the anatomy of your foot. To center the frame on your UFS boot slide the frame fully forward, toward to the front of your boot.  To bias the frame 3 mm towards the rear, slide the frame fully toward the heel of the boot.  To be clear: centering the frame mounting bolt in the slot does NOT center the frame. 

IMPORTANT: The rear of the frame is marked "endless".  The front of the frame is marked "arc".  Do not be the person that posts their new Arc setup to Reddit or Instagram with the frame installed backwards.  

The following pic shows where the frame bolt would be for a centered mount.

165 (Raised Heel Mount)

There are multiple mounting slots on the frame that will allow you to achieve centered and offset mounting on a variety of boots. The longitudinal slots allow for front-back adjustment so you can center the frame, or fine tune the position of the middle pivot points relative to the anatomy of your foot. Please note that very little lateral adjustment will be possible when using these slots, especially if your boot uses 5/16” frame bolts like Seba and FR. If you require lateral adjustment to correct anatomical issues like pronation or misalignment on carbon boots, the frame’s lateral slots are compatible with the rearmost threaded holes on 7-hole mounts that some boots have. We recommend always using a washer with your frame bolts, and applying fresh blue loctite every time you change your frame. This will give you the strongest and most reliable joint between the frame and boot.

For boots with only a single 165 mm frame bolt in the front and rear (like FR/Seba FRX, or Micro plastic boots): use the longitudinal slot to align the frame.

For Adapt boots: use the longitudinal slot to align the frame. You will have to remove the four Quattro mounting bolts for frame clearance. Some lateral adjustment may be possible due to the 6 mm frame bolts and float of the mounting bracket within the carbon shell.

For Rollerblade boots: use the longitudinal slot to align the frame. A small amount of lateral adjustment may be possible if your boot uses 6 mm frame bolts.

For boots with a 5-hole mount (like FR Spin, Seba Trix): use the longitudinal slot to align the frame. Lateral offset may be achieved by using the outside threaded holes of the mounting pattern.

For boots with a 7-hole mount (like FR1, FR2, FR3, FR/Seba/Micro carbon boots): you may use the longitudinal or lateral slots to align the frame. With this mount type you have the flexibility to use 150, 165, 180, or 195 mm spaced mounting (165 mounting is shown in the picture below). For a firmly fixed and centered mount, align the center threaded hole in the heel, and the most forward threaded hole in the front with the longitudinal slots. This will give you a 180 mm mount that locks the frame in all directions.  Lateral offset may be achieved by aligning the lateral slots with the rearmost threaded holes of the 7-hole patterns.


Configuration Axles

Each Arc or Arc ES Frame set includes four (4) Black 2-piece Configuration Axles. These allow you to configure the frame for use with either 80 or 84 mm wheels. The same amount of standard rocker is present in both setups. We call this Arc I Rocker.  

  1. Orient black axle so that circular dot is facing UP when using 84 mm wheels.
  2. Orient black axle so that circular dot is facing DOWN when using 80 mm wheels.

UFS (Flat Mount)

165 (Raised Heel Mount)

Deluxe Rocker Axle Kit (Silver Axles)

An optional Deluxe Rocker Axle kit allows advanced skaters to explore two settings of increased rocker when using 80 mm wheels. This special set of Silver Rocker Axles can be purchased separately. Please note these silver axles will not work with 84 mm wheel, unless you want to create a terrible feeling anti-rocker experience.

Endless Arc - Deluxe Rocker Axles

When oriented dot down, the silver axles create a rockered experience approximating a well-worn set of wheels. We call this Arc II Rocker. The frame becomes more agile and swively at the expense of cruising stability. When the silver axles are oriented dot up, an even more aggressive rocker is achieved.   

Axle Configuration Summary

Wheel Size
Rocker Intensity
Front Axle Rear Axle
84 mm Arc I (standard) Black UP Black UP
80 mm Arc I (standard) Black DOWN Black DOWN
80 mm Arc II (more) Silver DOWN* Silver DOWN*
80 mm Arc III (most) Silver UP* Silver UP*
80 mm Extreme Black UP Black UP

* Silver axles are optional and must be purchased separately.  

We invite you to explore various combinations of dot up and down with the front and rear axles to create custom rocker profiles that suit your personal skating style. You can even mix black and silver axles for a rocker that emulates an ice skate—e.g. silver axle dot down in front, and black axle down in back using 80 mm wheels.

Axle Installation

  1. Align the bearings, spacer, slot, and screw hole using a skate tool or a wooden pencil (see video).  We recommend the Sonic Sports skate tool, which has a bearing alignment feature.  When all these features are aligned, it will make inserting the axles much easier.
  2. Insert the black (or silver) Configuration Axle into the slot with the dot oriented up or down as required.  The end of the axle should insert into the 6 mm hole on the far side of the frame, and the head should sit flush.
  3. Thread the 5 mm Axle Screw into the female threads of the Configuration Axle.  Use a 4 mm hex key or skate tool to fully install the screw into the end of the axle.  Once it stops turning easily, snug the screw about an extra 1/8th turn (see video).  Do not overtighten.
  4. Carefully thread the three standard speed axles into the middle wheel positions.  Do not overtighten.

Wheel Selection

The Arc frames use 76 mm wheels in the middle three positions, and either 80 mm or 84 mm wheels in the front and back.  This gives you a lot of flexibility when choosing wheels.

Through extensive testing we have concluded that the best rocker experience occurs when all five wheels have the same profile. We highly recommend that all five wheels either have a matched bullet profile, or a matched round profile.   Do NOT mix wheel profiles.  For example, if your 84 mm wheels are bullet profile, and your 76 mm wheels are round profile the rocker will be unpredictable and inconsistent as you transition through your edges.  Matched sets of wheels can be purchased through our online store.  We also recommend that the durometer (hardness) for all wheels be similar if possible.

Round profile wheels provide a little more stability at the expense of speed.  Edges feel wide and continuous.  Conversely, bullet profile wheels provide snappier edge transitions and faster speed.

It’s important to note that the Undercover “full” profile is different than bullet and round profiles. It has tapered side walls with a compound radius that transitions from a smaller radius on the inside/outside edges to a bigger radius on the center edge. There is presently no round profile Undercover wheel being manufactured in the U.S.A.  We do not recommend mixing Undercover “full” profile with round or bullet profiles.  

Recommended wheel sets: 

  • Bullet: Rollerblade Hydrogen 84/76 or 80/76 mm, Endless UC 84 mm + FR Junk Freestyle 76 mm
  • Round: FR Street Invader 84/76 or 80/76 mm
  • Full: Undercover (various): 80/76 mm - double check the profiles carefully before using.  

Wheel Rotation

Wheel wear will always be unique to the way each individual uses their skates, and no two skaters will ever have wheels that looks the same after skating the same distance.  The goal is to rotate wheels so that a consistent rocker and edge wear pattern is maintained before needing to replace the wheels.  The more often the wheels are rotated, the more consistent the feel of the rocker will be between rotations.  We recommend one of the following wheel rotation schemes:

  1. Flip each wheel in place to wear inside and outside edges evenly.  This scheme may slightly exaggerate the rocker over time, as most skaters tend to wear their outer wheels more heavily.
  2. Swap 1L (front left) with 5R (rear right) and flip; swap 1R with 5L and flip; swap 2L with 4R and flip; swap 2R with 4L and flip, swap 3L with 3R and flip.  This scheme will balance wear between left and right frames, and between the front and back of each frame.  

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