【簡單生活單車坊】鋁合金公路車 將會是2012的市場新寵？！

最近店長聽到一則說法是那麼講的，就是2012年大家會以鋁合金公路車為入手標的！



原因呢？因為鋁合金車架剛性高，爬山、特別是像武嶺啦，新中橫啦，比較佔便宜，而且新一代鋁合金車架越來越輕，碳纖車架的優勢有限，況且碳纖還是有不易維護的問題！

乍聽之下覺得好像有點道理，但是，鋁合金真的會變成新寵嗎？到底有多寵呢？店長心裡實在沒底，這個問題應該要問捷安特經銷店的意見，畢竟，他們什麼都有，又是公路車銷售最多的品牌，Giant店老闆們應該比我們清楚得多！

先不管那個說法的真實性如何，店長個人以為，主流的三種車架材質，本來就是各有優缺點，也各有擁護者，否則怎麼能在市場存活呢？

這些年，碳纖車架的售價慢慢變得比較平易近人，尤其去年Giant打出 39,800的 TCR  Composite 1 後，碳纖車架不再高不可攀了，雖然，高階的碳纖車架，依舊讓大多數人「望之生畏」！

在這樣的情況下，怎麼突然說2012公路車架銷售主流會是鋁合金...，店長我是無法理解的！

再說吧，如果爬坡要鋁車才好用，那麼大多數爬山賽事的車手們，應該都會放棄碳纖車，改用鋁車架吧...！？但現實是這樣嗎？？好像不然！

如果說鋁車架便宜，那Giant 今年的廉價鋁車也只剩 TCR 2一輛了，到TCR SL 好像也不怎麼便宜了！
拉拉雜雜說一堆，其實我無意貶低任何一種材質，如前所述，沒有優點是無法在市場生存的！

我對鋁車比較的深刻感受有三次：
第一次是我長期試騎自家入門鋁車KHS K35，就是硬梆梆，騎個3、50公里還好，再長一點我的身體就受不了...。

第二次是騎 KHS A6200 登山車去環島，第三天晚上過雙園大橋準備要進入高雄市時，我已經完全無法忍受任何來自地面的崎嶇震動，想把車丟到橋下去....，不是車架壞了，是連續三天，每天平均超過200K的路程，讓鋁車架在我身上累積了太多的疲勞，到了耐受力變成0分的地步...！

第三次是試騎張老師的 Cannondale CAAD 10，果然是高級鋁車、速度機器，反應超直接超迅速，當然也非常忠實地反應了所有的位移和震動...，辛苦張老師騎慣了碳纖車，CAAD 10 才騎3次，就說要賣了...！

我想我跟張老師應該差不了多少，只要單日里程太長，即便是硬一點的鋼管車，我一樣受不了！9月初跟主教兩個騎「一日北高」，我們都騎的是 KHS Club 2000 鋼管車，Clumbus SL 管子不能說差了吧，到台南市區的那段台17線，大約才騎了320公里左右，因為是在市區內，道路使用率高，坑洞多，我們兩個是給震得.......唉唉叫啊！那個時候你就會想：「管他多重，給我高碳鋼....其餘免談...！」哈哈哈！

扯那麼多，我得收尾了！

總之，

1. 你愛硬、愛直接，不在意震動，不要那麼貴，那就是鋁車架囉。

2. 如果您愛硬、愛直接、但是又希望車子輕一點，震動少一點，那就是硬派的碳纖車架了。

3. 最後，如果只是想舒服巡航，鋼管車架就是優選，軟派的碳纖車架應該也不錯！





有人問，那我騎鋁車通勤不行嗎？當然行啊！只要自己尬意、怎麼都行！！

又，沒說車買來一定要天天騎啊！..........

就還是那事兒我不懂，一級鋁車的價格添一點可以買二級碳纖車架了；入門級的鋁車根本比普通鋼管車還難騎，怎麼說爬武嶺就要鋁車呢？

這是我的感覺啦，聽不慣的就當我胡說八道一番....





請參閱：


1. 比較鋼管車架、鋁合金車架、和碳纖車架_有何不同？

2. 鋼管車的特色是什麼？

補記：以下是一位前輩給我的教導，英文部分大致是引用文章，中文部分是他的總結！

Stiffness
This is where steel shines, as compared to Ti and Al. Young's Modulus for steel is approximately 30 million pounds per square inch. The titanium alloy
Ti3Al-2V is 15.5 million psi, and 6061 aluminum is approximately 10 million psi. Those ratios (three to two to one) are almost identical to the density ratios
between these three materials. That means that the stiffness-to-weight ratios for the three materials are about the same (provided you're looking at
stiffness in tension or compression).

If you really want to know, Young's Modulus is the ratio of stress-to-strain in the region below the proportional limit on the stress-strain curve. All you need
to know is: the bigger the number, the stiffer the material. Wait a minute, though. How come, if steel is so stiff and Al is not so stiff, that those big-tubed
aluminum bikes are so incredibly stiff? Young's modulus measures the stiffness for all of these materials with the same-size specimen, or section. We can
call the measurement section modulus. One of the pieces of the puzzle the bike designer gets to throw in is the size and wall thickness of the tubing used.
Then we get to figure the polar-section modulus of the material by the formula: 0.196 (D4-d4)/D). All this formula says is that as a tube's diameter
increases (D), the stiffness increases to the third power of that number (d is the inside diameter). Comparing a one-inch tube and a two-inch tube of equal
wall thickness., the fatty is going to be eight times as stiff as the little weenie tube. And the weight will only double. Now does the ride of those Kleins and Cannondales start to make sense?

Your next question should be: "Why not increase the diameter of steel tubes like you do with aluminum, so that we get an even lighter bike?" This is where
the "beer-can effect" comes into play. As a tube's diameter-to -wall thickness ratio gets above 60- or 70-to-one, the tube is more likely to suffer failure due
to buckling, or "beer canning." Al and Ti, being lower density materials, allow you to have thicker, buckling-resistant walls.

Elongation
Once again, this property is an indicator of ductility. Simply, it measures how far a material will stretch before it breaks. While the previous properties -
density and stiffness - don't change significantly with alloy and heat treatment in any given material, elongation is another story. Like strength, elongation
is all over the map depending on heat treatment and the nature of the alloy. Elongation is expressed as a percentage.

When tensile testing a material, it's pulled apart and stretched until it breaks. Marks are made on the specimen, and the distance between them is
measured before and after the specimen breaks. The difference is expressed as the percentage elongation. Steels used in bike tubing typically measure
elongations of 9 to 15 percent. If the elongation number dips below 10 percent, I consider it a flag to take a closer look at the overall properties of the
material.

Risk of brittle frame failure increases as this number decreases. In particular, you need to look into the strengths of the material - toughness and the
endurance limit.  Accurately analyzing a material with low elongation requires a lot more information and expertise than I can provide you in this short and
sweet synopsis.

Tensile Strength: Ultimate and Yield
There is a huge variation in the measured tensile strength of different steel alloys and different brands. Generic CrMo might have a yield strength of 90
KSI, whereas True Temper OX3 measures out at almost twice as much: 169 KSI. It's possible for a bike that's made out of either of these materials to
break. We know for a fact that straight gauge American airframe tubing is a very reliable material to build a bike with. But it has a strength of only 90 KSI.
Again, maybe we'll find that the toughness and elongation of this material is fantastic, so we can get by with a lower strength.

If the True Temper OX3 tubing is twice as strong, does that mean you can build a frame with half the wall thickness? Yes. Will it be as strong? No. Will it be
as stiff? Heck no. Will is last as long? Doubt it.

The Big Picture
The point here is that there is a lot to consider. If you merely look at a couple of the numbers, you're not necessarily getting the whole picture. It's easy for
a metallurgist to convince an ad guy about the superiority of one material over another. Look at the two materials mentioned above. Very different
strength numbers, identical density, yet you can build a good bike out of either material.

Steel is a wonderfully reliable material for building bikes. It's safe to say that there's no more successful material ever used. It's easy to work with, can be
easily welded or brazed, requires simple tools for fabrication, fails in a predictable manner (as opposed to sudden or catastrophic), and is cheap!There
have been few challengers to steel's throne of best material in the last 100 years.

上面文章，說明了一些材質的性質。因鋁本性不強又軟、elongation也不佳、要用大直徑tubing、所以很硬（管越大，越硬—Diameter 之三次方）。

#1 鐵 density 最大、所以最重.  Elongation、 tensile strength 都比鋁佳，但不能太薄(beer can effect），無法太輕量化。

#2 鋁之elongation不好，本性軟、加大直徑、因而變得太硬！有些較貴鋁合金的elongation較接近鐵。

#3 Carbon---硬、軟度可調整。

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• 留言者: thomas sun
• Email: thomasyaya@yahoo.com.tw
• 網址:
• 日期: 2011-10-25 22:05:58

各種管才我騎過

碳車 是我較不太喜好的材質 舒適 重抽會有釣魚竿的回彈

鋼管 雷諾算是有韻律的管材 我喜歡櫻花鋼 不是過度的硬˙˙稍帶點吸震彈性 義大利鋼管車 彈性適中 英國鋼管篇舒適取向



鋁車架 我騎過giant  tcr硬 但是抽車 五通會扭曲 要屬排行死硬的鋁車  屬 CERVELO SOLOIST TEAM 硬到爆  路面的一立石子都會感受到 下坡過減速條

會讓你五臟酥麻˙˙˙˙優點 就是反應超快 不是一級碳纖車能比 爬坡直接 適合單日賽

其實我認為事先了解 個人騎乘目的 習慣 時間長短 單日 或多日等等  再來決定車架材質 應該是較適合的選擇 再說車架幾何的設定也是搞率的因素之ㄧ

偏休閒 偏競速 偏長途休旅 或混血車架





[版主回覆10/25/2011 22:31:58]
感恩您又來指導小弟！

我看您單速車騎到懶得理我們咧....！

關於碳車我跟與您類似的看法，可能因為小弟體重快90，上週六去騎拉拉山，最後那段、抽車抽到我覺得它快扁掉、往下不往前，當然Ultegra輪組不那麼耐我抽，但是整體感覺還是...！

不過我那輛 KHS K90 碳車就沒那個問題，太平山抽得很愉快咧！

這表示我還需要多瞭解、多學習！

您說的對，選材質首先應該考量「用途」！