煞車 Braking

大西瓜皮

&nbsp;煞車 Braking <p>在不同地形正確使用煞車是展現操控力和自信的重要指標，如何使用煞車來控制速度是一項微妙的技術，我們試著來講解一下：<br/>當前後任一個煞車作用時，因為慣性的關係會在單車的前端產生一個下壓力，前輪的抓地力因而增加，後輪抓地力反之降低。所以前輪是制動的主要力量，而許多人害怕使用前煞則是因為沒有正確把重心向後移，要避免翻車且增加制動力就必須把重心往後移。<br/>Learning how to use your brakes in a variety of terrain is a major part of having control and confidence, breaking to control your speed is a tricky skill; so let’s take a closer look.<br/>When either brake is applied, your momentum creates a downward pressure on the front of the bike. Increasing front-wheel traction, while decreasing rear-wheel traction. The fear of grapping too much front weight results in many riders not using shift yet a proper weight transfer the majority of stopping power is in the front brake, in addition in keeping you from going over the bars shifting your weight back will greatly enhance traction when you use the brakes.</p><p>這個練習是學習如何最大化煞車制動力，從起點開始滑下來先不煞車，直到煞車點開始。首先試後煞車，同樣用最大的力道，你可以先試著正常姿勢，藉由屁股離開坐墊往後移，找出最大的制動力。<br/>“ Ok in this drill we going to learn how to maximize our braking traction, from your starting line coast without breaking down to the spot where you planned to apply the brakes, first use your rear brake stand up on your pedals and get in the crouched position off the saddle push the hips back experiment with moving your weight back to find the position for maximum for maximum braking traction.</p><p>10:44<br/>我們會發現，後煞車很難減速，其中一個原因是我們很難把整個重心轉移到後輪之後，所以要儘可能把重心往後移才可以得到後輪最大的制動力。然後試著調整煞車力道，最好的制動力發生在輪胎即將鎖死但還在轉動的時候。<br/>Ok well we noticed there it’s hard to slow down using just the rear wheel, one of the reasons is that you can’t get your weight behind the rear wheel obviously, so what you want to do get your weight behind the saddle so it’s over the rear wheel as much as possible.Then try to modulate with your brake lever, so that your wheel is just, just about to lock up but still turning a little bit. And that is probably the maximum braking traction at your rear wheel.</p><p>接下來只用前煞車，前煞車是減速以保持操控的最佳武器，但你必須知道如何正確使用它，你越用力拉前煞車把手就必須越把重心往後移，不能死死的一直拉住煞車把手而必須調整力道使得前輪不至於鎖死，才可以保持抓地力和操控性，當前輪有打滑跡象時必須扶直。好，很明顯的，前煞車比較快可以煞住，因為所有的重量都在前輪的後面，慣性產生的下壓力迫使前輪更吃進土裡面而得到巨大的制動力，但同時前輪也變得很難操控。剛剛發生在Kent身上的就是因為他前輪稍微轉向一邊然後跟著傾向一邊，打滑之後就沒辦法平衡而犁田。所以做這練習時要保持直線不要轉彎。然後，再試著前後煞車一起使用，配合重心移到後面，可以得到最大的煞車制動力。<br/>Next try using the front brake only it’s your best weapon for scrubbing off speed to maintain control, but you have to know how to use it correctly the harder you squeeze the front break the farther back you have to adjust your weight, apply the break constantly modulating the pressure, this allows the wheel to keep rolling so you can maintain traction and stay in control keep the front wheel straight as it tries to twist.Ok, so it’s obvious from the front break drill that you can stop much quicker you got all the weight behind the front tire so it is pushing the tire into the dirt so we have a tremendous amount of braking traction, but at the same time it can be hard to control what we saw happen with Kent is his front wheel back turned a little bit and than his bike leaned to side a little bit and when that happened the front brake still on causing his front wheel to wash up, so when you using your front brake, it’s important that your bike not be turned and that you be straight up and down. Try use both brakes together again coordinate the use of your brakes, with weight shifting to get maximum stopping power.</p><p>12:15<br/>關鍵在於找出拉煞車的力道，讓輪子瀕臨鎖死但仍在轉動，Janet，那就是最大制動力發生的時候。煞車有一些設定可以調整，以利正確操作，例如煞車把手的角度，我喜歡的角度是當「戰備姿勢」時拉住煞車把手的手腕最少程度的彎曲（與手臂平行）；調整把手的操作間隙（煞車片與輪框的距離），讓手指可以彎曲扣住把手比伸長來拉要好（即煞車不要太緊）。<br/>The art is to find breaking pressure, just before your wheels lock up.”Janet, listen to that tsjirp right before your wheels start to lock up” that’s when you get maximum traction.” Effective braking requires an upper set up on your brakes; there are several different adjustments you can make on your brake levers; one important one is the angle of your lever, I like the lever set so that in a down hill attack position, there is a minimal bend in my wrist, adjust the brake lever placement, so you fingers may contact just inside the bend, set the pads and reach adjuster for rim contact when your fingers have good force on the lever rather then when your fingers are extended.</p><p>13:10I<br/>我們來問問世界XC冠軍—John Tomac，「John，事實上最佳減速的方法是用力拉前煞車，你有何建議讓大家習慣於多用點前煞車？」，「嗯！我會建議先直線練習，先適度的拉前煞車，然後逐漸增加力道。前煞車是減速的主要制動力來源，尤其是下坡的時候」。好，這些是基本的煞車、踩踏、改變重心的技巧，接下來來介紹一些爬坡技巧。<br/>asked John Tomac, cross country world champion for his braking “so john actually the best way to slow yourself down is getting hard on the front brake.”What advice do you have about people who are trying getting used to use the front brake more?<br/>Well I would say practise in a straight line and practise grabbing as much front brake as you feel comfortable with and keep increasing that my front brake is mainly use to slow down the bike that’s why get the most braking powers at the front brake and that’s really giving you number if you braking down hill. Ok so that’s it for the basic skills.Knowing how to brake pedaling efficiently and position yourself on the bike are the tools you need to advance, now let’s look at using these basics and some pacific climbing conditions.</p><p>&nbsp;&nbsp; <br/>&nbsp; 我的煞車經 <br/>喜好追求速度的一夥聚在一起， 最常熱烈談論的話題不外是…轉彎處如何做出高危險度傾斜過彎、轉彎速度如何的快速、下坡時速能飆達多少時速、有沒有膽量再挑戰自己的極限等…隱藏在這些高超技巧表像背後，需要的是高超的剎車技巧，常使用剎車或是緊急剎車也不代表是遲頓， 正確來說，剎車應是如何在正確時機、最短時間、最短距離內降到您預期中的速度！ </p><p>為了正確的剎車，我們必需了解剎車到底會發生什麼事；事實證明唯有前後輪同時全力剎車才能獲得最短剎車距離，剎車距離取決於剎車功能(剎車塊與輪圈的搭配)及輪胎與地面的摩擦程度，大部份剎車力道會經由前輪傳達出來，前輪及後輪的制動力比例約為70%比30%，因為在剎車過程中，整個車身重心會往前移動，所以在剎車時臀部應離開座墊將身體重心往後移動。 </p><p>在練習剎車技巧前，必須先調效 出適合個人騎乘風格且能有效發揮剎車功能的壓點(煞車塊接觸到輪圈)，有二點需要注意：<br/>1.拉剎車把手的手指最前端第一節關節能有效彎曲扣住剎車把手，手指全力往內拉住把手時，第二節關節必需大於90角，且拉桿起碼距離握把有一個半指頭寬度裕度，避免長距離下坡剎車塊的磨耗，造成剎車把手碰到握把上的手指，影響剎車功能。<br/>2.較高級的剎車把手可調整把手施力點的槓桿比，造成剎車力道手感上軟硬的差異。 </p><p>全力剎車基本騎乘姿勢：<br/>1.臀部迅速往後移離座墊同時，穩踩住踏板，手臂伸直，目光朝前。<br/>2.在確實將臀部往座墊後方移離才能做出接下來的動作…儘可能再降低身體， 此意謂您的臀部會位於座墊的後下方，甚致您的胃像會碰觸到座墊一般…其姿勢和陡下坡的姿勢一模一樣。<br/>3.全力拉剎車把手，在前後輪不打滑且逐漸增加剎車力道的同時，隨時調整重心位置，直到感受剎車到後輪剛好浮離地面的程度(此時是最有效率的剎車)。 </p><p>“前空翻”不是前剎車力道太強的原故，而是沒能利用重心的轉換及利用伸直手臂來支撐往前的加速力道，若是全剎車時前輪快打滑，迅速短暫釋放前剎車把手可解除其窘境。 </p><p>但若前輪剎車力道低於後輪，意指後輪的減速力太大…就會產生大家耳熟能詳的”甩尾”動作，只要短暫釋放後剎車把手即可。 </p><p>全剎車技巧可運用到以底下二點之外的任何剎車條件上： </p><p>1.濕滑或鬆軟路面：地面和輪胎間摩擦力降低，若百分百使用全剎車，會加重前輪荷重，導致前輪打滑失控。 </p><p>2.顛簸路面：尤其OFF-ROAD高速行駛時，車身可能會跳離路面，若於前輪尚未落下的瞬間前剎車把手拉起…前輪鎖死失控打滑。 </p><p>要是把爆胎或是剎車故障算下去的話…這四種狀況就必需仰賴後剎車的有效運用，但其姿勢是和全剎車的基本姿勢是完全相同的。 </p><p>還有一種緊急狀況是必需運用到後輪剎車的高級技巧…彎道後輪滑移過彎。 </p><p>進彎前必需完成剎車動作以安全的速度過彎是過彎基本的技巧，若必需於彎道中剎車，我們必需了解到此時輪胎不僅承受著剎車力道，更須承受側向離心力，這導致後輪很容易側滑；但若進彎的速度太快，就只能靠後輪滑移來輔助過彎，這技巧是當您過彎失速時唯一的救命技巧。但若想以滑移代替緊急剎車，基本上只會拉長剎車距離，而且剎車最難掌握的就是後輪滑移剎車。 </p><p>滑移過彎姿勢：<br/>1.放下過彎內側腳。<br/>2.拉緊後輪剎車同時，以內側腿為支柱撐住地面，維持身體重心。<br/>3.操控前輪過彎動作。<br/>4.前輪快出彎時，放開後剎車把手，使後輪恢復抓地力及拉正車身，將內側腿放回踏板上加速離彎而去。 </p><p>常有人提到「後剎車力道太過軟弱」或是「車架後三角剛性不夠造成剎車力不足」…除非您是一位常將自己速度推向個人極限邊緣、要求極準確的剎車點，且具有極佳剎控技巧的人，不然加裝剎車補強板遭遇狀況時，可能會造成後輪常失控的情形；反倒不如透過在不同路況之下，練習前後剎車力道的運用、熟悉輪胎和地面間摩擦力、了解車架特性應是更加來的重要。 </p><p>另外提醒…除非您是在專為單車開發出來可以練習後輪滑移的場地，不然儘量避免此一動作，我們除了要留給他人對單車騎士一個好印象，也該尊重其它任何用途使用者，更應要維護我們賴以生存的土地。<br/></p>[em07]