Honda GB500 Parts for repair and restoration
Honda introduced the GB500 Tourist Trophy as a traditional-style road-sport model in 1985. For service, identify the fitted brake and master-cylinder components, then check the model year and part reference for each repair.
Brake-pad service
Replace contaminated, cracked or worn friction pads and inspect the rotor and caliper movement at the same time. The Honda brake pads fit GB500 1989–1990 and replace OEM 43105-MB4-007.
Sold individually; compare the backing-plate shape and retaining hardware to the fitted caliper.
Caliper rebuilding
For a leaking or sticking caliper, the caliper repair kit covers GB500 1989–1990 and is specified for front or rear use.
Choose the kit for the caliper being serviced; check piston and seal fit before assembly.
Master-cylinder reservoir
A swollen or damaged reservoir diaphragm can leak at the master-cylinder cap. The front master-cylinder reservoir diaphragm covers GB500 1989–1990 and replaces OEM 45520-MA5-671.
It is sold individually. Match the outline and cap to the installed master cylinder.
Choosing parts for your Honda GB500
Use the model year: Honda's archive records the GB500 Tourist Trophy's introduction in 1985. The brake pads, caliper kit and front reservoir diaphragm fit GB500 1989–1990. The 1985 introduction is a model-history date; identify the fitted assembly before ordering.
Match the brake component: the caliper kit is specified for front or rear use, while the reservoir diaphragm is for the front master cylinder. Confirm the assembly and part shape on your motorcycle.
Cross-check references: compare pad reference 43105-MB4-007 and diaphragm reference 45520-MA5-671 with your original parts. If a previous owner changed a caliper or master cylinder, identify the fitted component before ordering.
Building a custom Honda GB500?
For a café racer, tracker or other custom build, browse universal handlebars and grips and mirrors and adaptors. Check clamp diameter, mirror threads, cable reach and steering clearance; universal accessories may need modification on your motorcycle.
Why riders choose PartsNMore
- Supplying riders since 2002
- In-stock parts held in our warehouse
- Fitment help before you order
Need help choosing a part? Send us your model year and the part number you are considering, plus a photo of the original part if available.
Shipping: Free ground shipping on U.S. orders with a subtotal of $50 USD or more and Canadian orders over $50 CAD.
Returns: Eligible unused, unaltered parts can be returned within 60 days with original packaging and no restocking fee. Electrical parts are excluded. See the full return policy.
Honda GB500 Parts questions
What model years do the GB500 brake parts fit?
The brake pads, caliper repair kit and front reservoir diaphragm fit GB500 1989–1990. Check each part reference and the assembly fitted to your motorcycle.
Can the GB500 caliper kit be used on either brake?
The kit is specified for front or rear caliper use. Select it for the caliper being serviced and confirm piston and seal fit before rebuilding.
Which front reservoir diaphragm fits the GB500?
The diaphragm fits GB500 1989–1990 and replaces Honda OEM 45520-MA5-671. Match its outline and cap to the installed master cylinder.
Was the GB500 Tourist Trophy introduced in 1989?
No. Honda introduced the GB500 Tourist Trophy in 1985; the brake parts fit GB500 1989–1990. Match the year and fitted brake assembly before ordering.