The top tube is an enhanced diamond oval with ridge stiffeners that counters the side-to-side flex and torsion of even the most aggressive climb.

上管是菱形截面，增强的背脊硬度抵抗最激烈的攀登中产生的弯曲和扭转力。

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Some bikes with slanting top tubes are measured as if there were a level top tube, they use the length that the seat tube would be if it was as high as the head tube.

而有些上管倾斜的车架， 会被当作水平上管的车架来测量。 立管长度就会从中轴中心量到立管上与头管一样高的位置。

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If it fails to inflate, or you need to top up the air, blow into this tube.

如果不能完成充气，或者你需要把气充满，可以往这个管子里吹气。

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You have a tube, a transparent--a tube--a hollow tube, and at the top of the tube you throw a ball through so it whips through the tube and it comes out.

用一根管子,一根透明中空的管子,从管子最上面,你丢进去一个小球,小球迅速穿过管子,飞出来

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In subsequent versions, the top tube has stayed, but much else has changed.

WSJ: Sjoerd Smit of Vanmoof: A Designer Spin on the Grandma Bike

The top tube also has lights built right into it.

WSJ: Sjoerd Smit of Vanmoof: A Designer Spin on the Grandma Bike

On top of the mess, one straight tube juts out, a square of gray duct tape hanging from it, flapping in the breeze, a flag of surrender.

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