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那天小江拿龍頭跟我交換以後他就有了史上最長的大攀龍頭而我就有了史上最短的小攀龍頭, 用的結果兩個人都很滿意, 其中的奧妙之處就嘿嘿嘿了.
嘿嘿嘿就是說這事情另有玄機.
Author: 橘祖
Post Time: 2009/04/15
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Replier: mark
Reply Time: 2009/04/15
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Replier: 尿尿小P
Reply Time: 2009/04/15
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Quote mark article-那天小江拿龍頭跟我交換以後他就有了史上最長的大攀龍頭而我就有了史上最短的小攀龍頭, 用的結果兩個人都很滿意, 其中的奧妙之處就嘿嘿嘿了.
嘿嘿嘿就是說這事情另有玄機.
Replier: mark
Reply Time: 2009/04/15
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Replier: mark
Reply Time: 2009/04/15
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Replier: Kevin
Reply Time: 2009/04/15
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Replier: Gordon (國棟)
Reply Time: 2009/04/15
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Replier: 短腿小陳
Reply Time: 2009/04/15
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Replier: 尿尿小P
Reply Time: 2009/04/15
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Quote mark article-龍頭應該用多長請看此文的說法:
I'll tell you right away: this article has no miracle solution for your stem dilemma, due to the nature of this very elaborate problem. Namely, while you could claim that a 185cm/6.2ft guy will most often be very satisfied with a 19-20" XC frame, it's impossible to know which stem will be right for any trials rider before he tries at least 10 different stem combinations.
Why is this so? It seems every trials rider has different riding stance, different riding style (i.e. considers bunnyhops or backwheel moves or something third to be most important etc.) and of course -- different frame, fork and bars. All this means he's more likely to choose a stem that will make it easier for him to bunnyhop or backhop or something else, meaning he's willing to sacrifice performance in one move for better performance in another. This, in turn, means two riders roughly the same height and riding same frames won't feel as comfortable on same stems. My trials colleague warpig claims it's due to "learned geometry" effect, I think it's more dependent on rider's current preferences (it changes over time perhaps?), but all of that doesn't matter since both theories have been proven at least partially wrong. :-)
The only safe way to determine your optimal stem length/rise is to try as much combinations as you can. This is, of course, either expensive (buying different stems) or complicated (getting your friends to switch with you for a day or two). You can go around looking for trials riders of your height and frame+fork specs, and then statistically build probability for certain stem specs that should fit you, but it's way more effort than most of us are willing to put in.
So what's left? Not much. Don't go to the forum and ask what stem is right for you, not just because forum users are getting The Rash when you mention stem issue, but because you'll hear all sorts of different stem specs and either get confused or buy the wrong one. Instead, I'll try to give you a starting point, which probably won't be the optimal for you, but hopefully won't be too wrong either.
Few small digressions before we get deeper into the problem:
First and foremost, there's a huge difference between a frame with suspension fork or that without (with a 400mm rigid). For example, I'm riding a Zebdi with 60mm travel suspension fork, which is about 435mm long (axle to top of crown), and therefore I need a bit lower rise stem compared to Zebdi with a rigid fork. It's best if you measure your fork, axle to top of crown (where it meets aheadset) and use it as corrective factor, but if it's a rigid fork, chances are it's 400mm long, which means you need a bit longer stem with more rise.
Also, your wheelbase means a lot for your stem choice. If you have a short bike (measure wheelbase: front hub axle to rear hub axle), meaning wheelbase under 1050-1060mm, you would need longer stem: 100-110mm, height dependant. If you have longer bike, around 1100mm, you would most likely ride with 80-95mm stems. (again: depending on your height)
Secondly, when I say 100/10 stem, that means a 100mm long stem (center of steerer tube to center of handlebar) with a 10 degrees rise compared to the ground plane. '100/10' is shortened for easier communication.
Thirdly, geometry of your bars will influence your stem choice, meaning bars with a higher rise will require less rise for the stem. This usually isn't a huge influence, but you should keep it in mind since some trials bars have very specific geometries.
Fourth and final thing: some riders feel like longer stems make them bunnyhop/japslap higher (easier preload) but reduce backwheel stability (they're too stretched) and vice versa, but other report how they found their ideal stem length and max out in all moves they do. As always, I'll say that every rider is different, and that you should try different combinations until you see what kind of rider you are.
Now, let's talk about influence of the stem to your riding style. A 185cm tall rider riding a trials specific frame (less than 14" size), rigid fork and a 1040mm wheelbase could choose a 110mm/10-15° stem. If he prefers bunnyhops and japslaps, he would most probably like a bit longer stem or a bit more rise, let's say 115/15 or even better: 105-110/30. If he prefers backwheel moves, he could wish for a lower rise stem, let's say 110/10 or 90/15, depending on his riding stance (put too short of a stem, and you'll have trouble maintaining backhop and controling pedalkick direction).
If he was using a 430-435mm suspension fork, a good starting point could be 100/10 or 90/15 stem, taking stems with more rise for ups (bunnyhops, japslaps..) and slightly longer and lower (10 degrees or less) for backwheel stability.
Now I wish I could tell you what to do if you were 170cm tall rider, but I don't have enough statistical data and don't want to tell you the wrong thing, so I'll just say that you should suppose the right length out of what you've read, ride with it for a while and then try to find a different stem to try for a day or two. Take these data as a starting point, take the average in everything and see what stem you can get/afford, and plan your next move. I'm convinced that if you do that, you won't get a stem that's too wrong for you (like I did with my first trials stem) and that limits what you can comfortably do on your bike.
You also need to think about your backhop stance. Usually, with wrong stance, you will find your stem unadequate (and have pain in lower back), when it fact stem would fits you perfectly if you straightened your back and bent your arms more . Try to backhop in front of mirror-glass windows or tape yourself backhopping, and study and adjust your stance.
Replier: mark
Reply Time: 2009/04/15
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Quote 尿尿小P article-Quote mark article-龍頭應該用多長請看此文的說法:
I'll tell you right away: this article has no miracle solution for your stem dilemma, due to the nature of this very elaborate problem. Namely, while you could claim that a 185cm/6.2ft guy will most often be very satisfied with a 19-20" XC frame, it's impossible to know which stem will be right for any trials rider before he tries at least 10 different stem combinations.
Why is this so? It seems every trials rider has different riding stance, different riding style (i.e. considers bunnyhops or backwheel moves or something third to be most important etc.) and of course -- different frame, fork and bars. All this means he's more likely to choose a stem that will make it easier for him to bunnyhop or backhop or something else, meaning he's willing to sacrifice performance in one move for better performance in another. This, in turn, means two riders roughly the same height and riding same frames won't feel as comfortable on same stems. My trials colleague warpig claims it's due to "learned geometry" effect, I think it's more dependent on rider's current preferences (it changes over time perhaps?), but all of that doesn't matter since both theories have been proven at least partially wrong. :-)
The only safe way to determine your optimal stem length/rise is to try as much combinations as you can. This is, of course, either expensive (buying different stems) or complicated (getting your friends to switch with you for a day or two). You can go around looking for trials riders of your height and frame+fork specs, and then statistically build probability for certain stem specs that should fit you, but it's way more effort than most of us are willing to put in.
So what's left? Not much. Don't go to the forum and ask what stem is right for you, not just because forum users are getting The Rash when you mention stem issue, but because you'll hear all sorts of different stem specs and either get confused or buy the wrong one. Instead, I'll try to give you a starting point, which probably won't be the optimal for you, but hopefully won't be too wrong either.
Few small digressions before we get deeper into the problem:
First and foremost, there's a huge difference between a frame with suspension fork or that without (with a 400mm rigid). For example, I'm riding a Zebdi with 60mm travel suspension fork, which is about 435mm long (axle to top of crown), and therefore I need a bit lower rise stem compared to Zebdi with a rigid fork. It's best if you measure your fork, axle to top of crown (where it meets aheadset) and use it as corrective factor, but if it's a rigid fork, chances are it's 400mm long, which means you need a bit longer stem with more rise.
Also, your wheelbase means a lot for your stem choice. If you have a short bike (measure wheelbase: front hub axle to rear hub axle), meaning wheelbase under 1050-1060mm, you would need longer stem: 100-110mm, height dependant. If you have longer bike, around 1100mm, you would most likely ride with 80-95mm stems. (again: depending on your height)
Secondly, when I say 100/10 stem, that means a 100mm long stem (center of steerer tube to center of handlebar) with a 10 degrees rise compared to the ground plane. '100/10' is shortened for easier communication.
Thirdly, geometry of your bars will influence your stem choice, meaning bars with a higher rise will require less rise for the stem. This usually isn't a huge influence, but you should keep it in mind since some trials bars have very specific geometries.
Fourth and final thing: some riders feel like longer stems make them bunnyhop/japslap higher (easier preload) but reduce backwheel stability (they're too stretched) and vice versa, but other report how they found their ideal stem length and max out in all moves they do. As always, I'll say that every rider is different, and that you should try different combinations until you see what kind of rider you are.
Now, let's talk about influence of the stem to your riding style. A 185cm tall rider riding a trials specific frame (less than 14" size), rigid fork and a 1040mm wheelbase could choose a 110mm/10-15° stem. If he prefers bunnyhops and japslaps, he would most probably like a bit longer stem or a bit more rise, let's say 115/15 or even better: 105-110/30. If he prefers backwheel moves, he could wish for a lower rise stem, let's say 110/10 or 90/15, depending on his riding stance (put too short of a stem, and you'll have trouble maintaining backhop and controling pedalkick direction).
If he was using a 430-435mm suspension fork, a good starting point could be 100/10 or 90/15 stem, taking stems with more rise for ups (bunnyhops, japslaps..) and slightly longer and lower (10 degrees or less) for backwheel stability.
Now I wish I could tell you what to do if you were 170cm tall rider, but I don't have enough statistical data and don't want to tell you the wrong thing, so I'll just say that you should suppose the right length out of what you've read, ride with it for a while and then try to find a different stem to try for a day or two. Take these data as a starting point, take the average in everything and see what stem you can get/afford, and plan your next move. I'm convinced that if you do that, you won't get a stem that's too wrong for you (like I did with my first trials stem) and that limits what you can comfortably do on your bike.
You also need to think about your backhop stance. Usually, with wrong stance, you will find your stem unadequate (and have pain in lower back), when it fact stem would fits you perfectly if you straightened your back and bent your arms more . Try to backhop in front of mirror-glass windows or tape yourself backhopping, and study and adjust your stance.
扯那麼大篇英文 ,
怕大家沒耐心看 ,
反正意思是以後只要跟 Mark 買車 ,車架幾何可以讓你試到爽為止再買 ....
救甘興A .
Replier: 橘祖
Reply Time: 2009/04/16
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Replier: 黑輪
Reply Time: 2009/04/16
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Replier: 橘祖
Reply Time: 2009/04/16
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Quote 黑輪 article-昨天戰鬥力不夠沒辦法變身超級賽亞人來對抗魔人普烏,這個老大比上次的八大"這樣有很好玩嗎?"的關卡還難,可能要小育出馬才打的贏了,看到他那麼大一隻,又會噴檳榔渣,我只好默默的離開~~~
橘祖,你沒去說書真是太可惜啦~~~
Replier: mark
Reply Time: 2009/04/16
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Replier: 尿尿小P
Reply Time: 2009/04/16
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Replier: Kevin
Reply Time: 2009/04/17
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Quote 橘祖 article-雖然這篇文章後來被拉走..... 就讓我使出一些力氣把這篇文章拉回來吧!!!
==== 腦殘遊記 =================
昨兒早我心裡便浮起晚上噴噴的念頭,原先的計畫是找小江來個東區噴噴團,但後來一直沒看到小江MSN上線,故打消念頭。沒想到,在下午約略四五點時,小江來電並說要過來內湖羞辱我,我心裡一邊對這種心電感應嚇了一跳,一邊想說敢來我的主場踢館真是太超過了!!於是就在btt上敢緊po文找人。
提早下班回家後,想到晚上還沒吃飽,怕等下騎車沒力氣,便將僅存的兩包泡麵拿出來,在泡的同時,由於擔心吃太多會不蘇湖,便僅先放一包,沒想到吃完後還是有種很餓的感覺,便在不換湯的情況下泡了第二包,事後回想,好險有多泡一包,難道這就是千金難買早知道的滋味嗎~~~~ 吃飽後,在客廳翹腳看新聞的同時,想到後輪還沒磨好,感覺放完氣,將框磨一磨,並裝回去調整煞車間距,但好景不常,也許是打氣時外胎沒固定好,外胎一直呈現某部份扁平的狀態,我百思不得其解,只好用手指頭沾沾口水,並接著在我的太陽穴旁畫圈,接著我想到用放氣跟調幅條的方式,成功解決偏擺的問題,原先外胎會磨到車架,讓後輪極為不順,而調整過後僅會在範圍內兩邊擺蕩,看到煞車跟輪框的接觸面像尿尿小p喝完美如一樣晃來晃去,我嘴角上揚了,但終就還是搞定了!!
接著小江也到了,而潛力極高的黑輪也踩著他的Neon到了!在一陣整裝之後,我們開始向熱身區前進。在熱身區,黑輪以一個zap tap接上一草叢平台,沒想到此時卻出現一個正義魔人說話了!『不要騎上去,不會去運動公園騎車嗎?』『模哩希咧靠腰喔!!』此句小育兄上周的經典句不斷在我腦海裡浮現,就在此時我努力的觀察黑輪,看黑輪對那身懷五甲,體重與身高一比一的正義魔人─普烏─會如何對付,以魔人普烏的戰鬥力,我跟小江的身上沒有大鎖,沒有刺刀(請參見魔人零一網站單車版),更沒摺凳,該如何是好呢? 不過好裡家在,此時黑輪就默默的下來,而普烏也就離去了!!
在還沒熱身的情況下,我們只好反向前進,一路玩耍拍滴逼(DV),中間歷經了一車給普(one-bike gap)、瑞喔騎乘(rail riding)以及巴士塞哈(80cm sidehop),一路上黑輪都展現他的穩定及越來越遠的跳躍長度,縱使如此,來踢館的小江還是無情的握著黑輪接進陰部上翹的那一根堅硬的龍頭(stem)說:『你這樣太短了!! 若是再長一點就更強了!!』黑輪此時流下男兒無情的兩行淚,而此時我心想著:『我要打十個!!』
最後我們騎到最後一關,也就是所謂的一米平台進行對決,一開始時我使出鍛鍊許久的塞哈(sidehop)來給小江個下馬威,沒想到他也輕鬆的上了,雖然在上去時會多一根!!! 但畢竟高度還是有優勢的,接著小江就開始一米的踩跳(pedal hop),他試了好幾次都在直接接後點時撐不住失敗,但雖然失敗了,還是能看出ECHO SL的加持讓他後輪成功的吃角並不會滑下來,接著我跟著踩跳,但這種高度是我第一次嘗試,最後在成功率不高的情況下,我失敗了!! 失敗後我不灰心,使出終極大絕─撞前輪,果然使出這一招後成功的將我推上平台,但卻總是在後輪滑下的情況下,宣告失敗,但撞前輪能完成上一米平台的完成度較小江的踩跳高,此時我看見小江泛紅的雙眼,他在一段沉澱後力圖振作,並使用出驚為天人且僅有他的大車及身高優勢可使出的zap tap接後點,並成功的躍上平台,我跟黑輪兩人瞬間跪倒在地,一直腳軟無法站立,最後只能望著小江巨大的背影離去。
Replier: 小江
Reply Time: 2009/04/19
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Replier: 小江
Reply Time: 2009/04/19
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Replier: 橘祖
Reply Time: 2009/04/19
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