然而這個夾角問題
Stallings wrote:
騎登山車，身體是直的，與地面夾角大約 45°
騎公路車且握下把，身體是縮的，與地面夾角大約只剩 30°，也就是離地面更近了(恕刪)
跟我看到的資訊不同(指的是角度大小)
在這篇"Descending" by Jobst Brandt (推薦好文, 連同Sheldon寫的Braking and Turning都值得一看)
That bicycle tires have no margin for recovering a slip at maximum lean angle, has been tested in lean-slip tests on roads and testing machines. For smooth tires on pavement, slipout occurs at slightly less than 45 degrees from the road surface and is both precipitous and unrecoverable. Although knobby tires have a less sudden slipout and can be drifted around curves, they begin to side-slip at a more upright angle as their tread fingers walk rather than slip. For this reason, knobby tires cannot achieve lean angles of smooth tires and offer no cornering advantage on pavement.
簡單來說
光滑胎的自行車最大頃斜角度是45度(在此如果滑了就很難回復)
巧克力胎的自行車最大頃斜角度其實是比光滑胎要小(因為胎粒走動而非滑動) 也因此在轉彎上沒有優勢
(這一點與一般的認知不同 要小心）
,誰告訴你騎登山車(下坡)身體是直的,
