{"product_id":"box-one-center-clamp-31-8mm-stem-1-1-8","title":"Box One Center Clamp 31.8mm Stem 1-1\/8\"","description":"\u003ch1\u003eBox One Center Clamp 31.8mm Stem 1-1\/8\"\u003c\/h1\u003e\n\u003ch2\u003eProduct Overview\u003c\/h2\u003e\n\u003cp\u003eThe Box One Center Clamp is a front-load stem designed for BMX racing with 31.8mm oversize handlebars. Cold forged from 6061-T6 aluminum with a dual mid-bolt wedge mounting system, it eliminates rear pinch bolts to reduce weight and knee hazard while maintaining strength. Features an open skeletal design and reversible 5-degree rise\/drop configuration.\u003c\/p\u003e\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cp\u003e• \u003cstrong\u003eCold forged 6061-T6 aluminum construction\u003c\/strong\u003e – Forging process compresses aluminum grain structure for maximum strength-to-weight ratio, creating the lightest oversize BMX stem available\u003c\/p\u003e\n\u003cp\u003e• \u003cstrong\u003eCenter clamp mounting system\u003c\/strong\u003e – Dual mid-bolt wedge design replaces traditional rear pinch bolts, reducing weight and eliminating potential knee contact points during crashes or sharp turns\u003c\/p\u003e\n\u003cp\u003e• \u003cstrong\u003eOpen skeletal design\u003c\/strong\u003e – Material removed in non-structural areas minimizes weight while maintaining stiffness at handlebar and steerer clamp interfaces\u003c\/p\u003e\n\u003cp\u003e• \u003cstrong\u003eReversible rise\/drop\u003c\/strong\u003e – Can be installed with 5-degree rise or flipped for 5-degree drop to adjust handlebar height and rider position\u003c\/p\u003e\n\u003cp\u003e• \u003cstrong\u003e31.8mm oversize handlebar clamp\u003c\/strong\u003e – Larger clamp diameter distributes clamping force over increased surface area for secure handlebar retention with reduced stress concentration\u003c\/p\u003e\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003cp\u003e• \u003cstrong\u003eMaterial:\u003c\/strong\u003e 6061-T6 aluminum\u003cbr\u003e• \u003cstrong\u003eSteerer tube clamp:\u003c\/strong\u003e 1-1\/8\"\u003cbr\u003e• \u003cstrong\u003eHandlebar clamp diameter:\u003c\/strong\u003e 31.8mm (oversize)\u003cbr\u003e• \u003cstrong\u003eClamp type:\u003c\/strong\u003e Front-load\u003cbr\u003e• \u003cstrong\u003eMounting system:\u003c\/strong\u003e Dual mid-bolt wedge (center clamp)\u003cbr\u003e• \u003cstrong\u003eRise\/drop:\u003c\/strong\u003e ±5 degrees (reversible)\u003cbr\u003e• \u003cstrong\u003eExtension lengths:\u003c\/strong\u003e 53mm or 60mm\u003cbr\u003e• \u003cstrong\u003eWeight:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e53mm: 244 g (8.6 oz)\u003c\/li\u003e\n\u003cli\u003e60mm: 246 g (8.8 oz)\u003cbr\u003e• \u003cstrong\u003eStack bolt:\u003c\/strong\u003e M6×20L (P1.0)\u003cbr\u003e• \u003cstrong\u003eClamp bolt:\u003c\/strong\u003e M8×20L (P1.25)\u003cbr\u003e• \u003cstrong\u003eMinimum exposed steerer required:\u003c\/strong\u003e 40mm\u003cbr\u003e• \u003cstrong\u003eCarbon steerer compatibility:\u003c\/strong\u003e Not compatible\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eCompatibility and Ideal Use Cases\u003c\/h2\u003e\n\u003cp\u003eDesigned for BMX race bikes with 1-1\/8\" aluminum or chromoly steerer tubes and 31.8mm oversize handlebars. Requires minimum 40mm of exposed steerer tube above the headset top cap for proper wedge engagement. Best suited for competitive racing where lightweight components and clean cockpit design are prioritized. The center clamp design eliminates rear pinch bolts that can contact rider's knees during crashes or aggressive cornering. Available in 53mm (shorter reach, more upright position) or 60mm (longer reach, lower position) extensions to accommodate different rider preferences and frame geometries. Not compatible with carbon fiber steerer tubes or standard 22.2mm handlebars—verify fork steerer material and handlebar diameter before ordering.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eNote:\u003c\/strong\u003e US orders ship direct from manufacturer and may arrive separately from other items. Available in 60mm length in black color only.\u003c\/p\u003e \u003cdiv\u003e\u003cp.\u003e\u003ci\u003e\u003cu\u003e\u003cfont size=\"2\"\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/font\u003e\u003c\/u\u003e\u003c\/i\u003e\u003c\/p.\u003e\u003c\/div\u003e\u003cdiv style=\"\"\u003e\u003ci style=\"font-size: 0.875rem;\"\u003e\u003cu\u003e\u003cfont size=\"3\"\u003e\u003cb\u003e\u003cbr\u003e\u003c\/b\u003e\u003c\/font\u003e\u003c\/u\u003e\u003c\/i\u003e\u003c\/div\u003e\u003cdiv style=\"\"\u003e\u003ci style=\"font-size: 0.875rem;\"\u003e\u003cu\u003e\u003cfont size=\"3\"\u003e\u003cb\u003e**Due to unique nature of this item, ALL sales of this product are FINAL. No Refunds or Returns**\u003c\/b\u003e\u003c\/font\u003e\u003c\/u\u003e\u003c\/i\u003e\u003c\/div\u003e","brand":"Box","offers":[{"title":"Black \/ 53mm","offer_id":45276261875891,"sku":"BX-ST14H1853-BL-Black-53mm","price":99.99,"currency_code":"USD","in_stock":true},{"title":"Blue \/ 53mm","offer_id":45275481538739,"sku":"BX-ST14H1853-BL-Blue-53mm","price":99.99,"currency_code":"USD","in_stock":true},{"title":"Red \/ 53mm","offer_id":45276261941427,"sku":"BX-ST14H1853-BL-Red-53mm","price":99.99,"currency_code":"USD","in_stock":true},{"title":"Polish \/ 53mm","offer_id":45276261908659,"sku":"BX-ST14H1853-BL-Polish-53mm","price":99.99,"currency_code":"USD","in_stock":true},{"title":"Black \/ 60mm","offer_id":45354377543859,"sku":"BX-ST14H1853-BL-Black-60mm","price":99.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0716\/8737\/2979\/files\/box-one-center-clamp-318mm-stem-1-1-8.jpg?v=1783442022","url":"https:\/\/time2shinebmx.com\/products\/box-one-center-clamp-31-8mm-stem-1-1-8","provider":"Time 2 Shine ","version":"1.0","type":"link"}