There are several ways to adjust the inner pad of the rear disk brake of your 500 Series or Core-5 Ebike.
- Use a 5mm hex wrench with a very short arm which fits in the gap between the motor hub flange and the adjuster.
- You can find stubby hex wrenches online or ultra low-profile hex wrench sets, or make your own! (see below)
- Assess the adjustment needed (look at the spacing between the rotor and pads), remove the bracket and caliper from the frame as one unit and adjust as needed with your standard hex wrench - reinstall bracket/caliper to frame.
*Do not remove the caliper from the bracket as this will require extra adjustment*
- (MOST DIFFICULT/subject to complication) partially Remove the Wheel far enough to allow a 5mm hex wrench to access the adjustment disk. To do this you need a bike repair stand or to flip the bike over. Ensuring your rear wheel is reinstalled correctly after adjusting your caliper is VERY IMPORTANT
Now that you have your tool, you are ready to adjust your back brake
Try to match the position of the wrench with the hex socket. The hex socket is beveled so the wrench can be tipped into it easily. Since the most likely adjustment needed is to reduce the gap between the brake pads, insert the tool with the long arm angled towards the rear so that it can rotate the adjuster forward (clockwise).
Follow the normal procedure for adjusting disk brakes.
Rotate the adjustment disk one click, and slowly spin the wheel at least one revolution to make sure the pad does not rub the disk (listen for a swishing sound).
You may need to rotate the adjuster more than one click stop. Do not leave adjuster between click stops. Back off one click if you hear a sound when you rotate the wheel. Test the hand brake and adjust/reduce the cable length using the barrel adjusters at either end of the brake cable. Refer to disk brake videos found on Ride1Up Support Solutions.
For all you DIY'ers out there, you can cut down the short arm of the 5mm hex wrench that was supplied by Ride1Up in the tool kit for assembling the Series 500 E-bike.
What is needed is a hacksaw, vice, and file.
The CR-V (chromiumvanadium) alloy is a hardened steel but with patience it can be cut.
The hex wrench with clamp naturally on its flats making it easy to rotate and cut evenly around the wrench.
Clamp the short arm so the cut is 8mm from the inside of the long arm as shown in Figure 1.
File the cut edges smooth.
Photos and DIY supplementary tool description courtesy of G. Schnakenberg, Jr.