A gauge made with our hope that Keirin riders perform at their best.
NJS CHAINRING GAUGE measures the "42mm±2mm standard" in NJS Keirin track bikes. As shown in the photo, place the V-groove of the gauge on the seat tube and check length (42 mm wide) from there to the centerline of the projection on the right side. If the installed chainring is positioned within the area of the thick line (4 mm wide), it meets the inspection requirements.
The material, hairline finished stainless steel, visually supports your work with its horizontal straight line. The edge of the product shaped by hand fits your hand and improve work efficiency.
*Be careful not to scratch your bike frames with edges of the gauge.
*This tool was made as a gauge for inspecting NJS track bikes. Please note that some other kinds of BB shells may not be measured correctly .
Advisor: Maebashi Velodrome Inspector, Kenji Ishii from Sunlight Yellow
Kino's bicycle diary: "街乗りピストのメンテナンス クランク取り付け チェーンライン確認"