4-2
ZRA_Aero Z Owner’s Manual
OM_ZRA_Aero Z_0913RevA
CHAPTER 4: BACKRESTS And PUSH HAndLES
Changing the Backrest Angle
Tools Needed:
• 1/2” Open End Wrench
• 7/16” Open End Wrench
• 1/8” Allen Wrench
1. Lock the backrest in the unfolded position.
2. On both sides of the chair, using the Allen wrench, remove the Button Head cap screws and lock washers. See
Figure 4-3.
3. On both sides of the chair, using the Open End wrenches, loosen but do not remove the stop bolts and nylock
nuts.
4. Adjust the backrest to the desired angle. On one side of the chair, while holding the backrest in place, align one
of the five holes in the backrest cam with one of the three holes in the back mount. Place the Button Head Cap
screw through the lock washer, the backrest cam and into the back mount. Finger tighten. It may be necessary
to make a minor adjustment to the backrest angle in order to properly align the hole in the link with an available
threaded hole in the bracket. Once aligned, reinsert and finger tighten the Button Head cap screw removed in
Step 2 to securely attach the link to the backrest assembly.
5. Repeat Step 4 on the other side of the chair.
6. Securely tighten the Button Head cap screws, stop bolts and nylock nuts.
Figure 4-3
Changing the Backrest Angle
Nylock
Nut
Backrest
Back Mount
Backrest
Cam
Lock Washer
Button Head
Cap Screw
Stop Bolt
Adjusting the Backrest Height
Tools Needed:
• 5/32” Allen Wrench
Note:
In order to adjust the backrest height, it is helpful to remove the backrest upholstery. Therefore, make a note
of the tautness of the backrest upholstery before removing it so you can reinstall it to approximately the same degree
of tautness.
1. Remove the backrest pad. See “Velcro
®
-Style Adjustable Back Upholstery” or “Tension Adjustable by Straps
Back Upholstery” on pages 7-1 to 7-3.
2. On both sides of the chair, remove the Allen screw that secures the backrest post inside the backrest. See Figure
4-4.
3. Reposition both backrest posts to the desired height inside the backrest, and reinsert and securely tighten the two
Allen screws.
4. Make sure both backrest posts are at the same height in the backrest.
5. Reinstall the backrest upholstery. See “Velcro
®
-Style Adjustable Back Upholstery” or “Tension Adjustable by
Straps Back Upholstery” on pages 7-1 to 7-3.
