Front Drum Brake Light Switch | Honda CB100 / CB125

Front Drum Brake Light Switch | Honda CB100 / CB125

Front Drum Brake Light Switch for vintage Hondas equipped with forward drum brakes.

Why You Need This

Years of repeated brake lever use can wear down the front brake light switch, leading to cracks, failure, or inconsistent brake light operation. Replace your old or damaged drum brake light switch with a high-quality front drum brake light switch designed to restore reliable brake light function on your vintage Honda motorcycle.

When swapping out the old switch, we also recommend looking over the rest of your front brake system for smooth operation and wear. We carry replacement Front Brake Shoes, Early Drum Brake Levers (CB100, CL100, SL100, CB125 S0-S2, CL125 S0-S1), Brake Levers (CB125 1976-1978), and Power Brake Levers (CB125 1976-1978) to help keep your vintage Honda braking smoothly and stopping safely.

Specifications

Note: *Requires Modification - This part requires a minimal modification to fit in the drum brake perch. Please see our installation instructions below for how to modify the brake light switch during installation.

Installation

Difficulty: Beginner

Tools needed: A sharp knife or box cutter

1. This front drum brake light switch requires a small modification before installation and may not fit all brake switch perches out of the package. Locate the small notch at the end of the switch housing before trimming.
2. Carefully trim the raised ridge on both sides of the brake light switch housing with a sharp knife. Do not cut the locating notch or rear of the switch. Watch the full installation video for more details.
3. Remove the drum brake lever, then route the brake light switch wires through the drum brake perch from the inside outward.
4. Seat the brake light switch in the perch housing with the locating notch aligned. Press it fully into place so the switch sits flush and does not stick out above the perch.

Take care to not pull the brake light switch through the perch by its wires as that can break the switch and cause them to pull out of the switch body. Instead, feed the wires by pushing them into the housing.

This video shows how to slightly modify the CMC #1038 front drum brake light switch so that it can be properly installed in the from drum brake perch on the motorcycle.

Frequently Asked Questions

Does this fit in my original handlebar perch?

Yes, but this switch will require a small modification to fit into certain brake drum perches. Please see our installation instructions for further details.

Will this brake light switch fix my brake light?

It might. The brake light circuit on these Honda motorcycles has two brake light switches in it, a front and rear, and also runs through the keyswitch. We recommend fully testing the components of your brake light circuit before ordering any replacement parts so you order exactly the parts that are broken. See our full troubleshooting guide to know how.

You Might Also Need

• Front Brake Shoes — Replace is worn out or aging
• Drum Brake Levers (CB100, CL100, CB125 S0-S1, CL125 S0-S1) — Replace if broken or in need of a spare
• Drum Brake Power Lever (CB125 1976 - 1978) — Replace for an easier to reach drum brake lever
• Drum Brake Lever (CB125 1976 - 1978) — Replace if broken or in need of a spare

Last updated: May 2026