Mild Blue Brake Sponge 15512: Test the Change
Tamiya 15512 contains blue brake sponge in 1, 2 and 3 mm thicknesses. Tamiya explicitly describes its effect as milder than the white 15492 set. That comparison gives a reason to test it when a current brake setup is too abrupt, but it is not a numerical braking-force claim or a guarantee of fewer derailments. Begin with your car's actual clearance and one repeatable course section.
Check fit before color
The product text lists MA, MS, AR, Super-II and Super XX chassis. Its page tags additional chassis, but the written list is the conservative starting point; compare your own stay and event rules. Place the car on a level board, measure the available space below the intended mounting point and check that the sponge will not touch a wheel or moving gear. A thicker piece changes the first contact height.
Change one variable
Record the previous sponge's color, thickness, length, mounting position and condition. Replace only one location at a time, using a cleanly cut piece with no lifting edge. Run several clean attempts at the same lane change or slope and note both successful finishes and failures. A different lap time cannot be attributed to the blue compound if the brake height and batteries changed together.
Keep the result local
If a softer response improves one course but leaves another jump uncontrolled, report both observations. Retire sponge that is torn, oil-soaked or peeling. Check the assembled car against current class rules. Tamiya's ‘milder’ statement is a product comparison with 15492, while the useful setup answer comes from repeatable runs on your car.
Check current availability and the exact variant on the product listing before ordering.
Related reading
Frequently asked questions
Is 15512 thinner than 15492?
Both sets offer 1, 2 and 3 mm pieces; Tamiya describes the blue compound's effect as milder.
Does blue sponge fit every chassis?
No. Check the exact chassis, mounting stay and current rule sheet.
Sources checked 26 September 2026: https://www.tamiya.com/english/products/15512/index.html, https://www.tamiya.com/english/products/15492/index.html. Recheck product availability before ordering.