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好耐都未出post, 最近忙於趕project, 就黎完成, 不如出下post 又講下車呔既野.
平時大家換新呔都係將新呔放前, 其實我自己都冇好研究呢樣野, 直至有個客同我講, 佢想要新呔放後面. 話我知因為新呔放後, 安全過放前面 (睇左個video 之後). 之後我就開始研究下呢樣野, 到底放前定放後好呢?
先俾大家睇下, 唔同既車呔制做商對於車呔放前定放後好既實驗. (可以睇下面, 綜合所講既野)
1. 米芝蓮做既實驗
http://www.michelinman.com/US/en/safe-driving/tire-safety/mixing-tires.html
2. 錦湖話後呔應該係新呔
http://kumhotyre.co.uk/kumho-news/should-you-fit-new-tyres-to-the-front-or-rear/
3. 台灣其中一個研究 (理論同錦湖一樣)
https://www.youtube.com/watch?v=FYNU2Gtig58
5. 放前定放後都有唔同意見
https://www.youtube.com/watch?v=6AyXpQBfr9c
綜合上面講既野, 新呔放後面既原因
A. 米芝蓮話實驗做出, 放新呔係前面, 如果開得太快令到甩尾, 部車會失控
B. 錦湖話, 因為understeer (轉向不足) 同 oversteer (轉向過度)會出現, 正常控制轉彎其實好少出現, 所以將新呔放係後面, 前呔(即舊的既呔) 咬力不大, 發生轉向不足時, 會易的轉番入黎. 如果前呔咬力大, 轉彎會更貼地, 就比較難轉番入黎 (唔知咁會唔會令大家明白的).
同樣, 發生轉向過度, 後尾會向前沖. 但新呔咬力比較大, 所以當剎車時, 後呔冇咁易失去咬力向前沖
(而大部分既車都係前輪驅動, 制做商都將呢的車整到較易轉向不足)
轉向不足同轉向過度既原因我就唔詳細講啦, 下次再講
新呔放前面既原因
A. 台灣被訪問既個位, 話因為放係前呔先會較易控制車既左右
睇左咁多樣野之後. 自己既感覺係
1. 米芝蓮既實驗唔係好說服到點解後呔要裝新呔. 因為做個實驗兩次, 兩次都係唔同既環境條件做. (車速同控制既條件). 第一次新呔放後就好普通咁渣個圈, 第二次新呔放前, 就叫人係咁加速, 成個條件都唔同晒.
如果新呔放係後呔, 其實前呔都有機會因咬加不足而失控. 用方向盤想轉去其他方向, 其實都可能救唔到, 因為前呔咬唔到地, 轉唔到你想去既個一邊
2. 錦湖既講法相信係令人較易明白同合理. 佢提出當發生呢兩者既關係時, 後呔係新呔會冇咁易出事. 講到好多車都會較左會轉向不足, 呢個會較易說服到人
3. 新呔放前呔, 的確係會轉向較易控制, 相信呢個大家都認同, 因為大家都會將新呔放前呔.
總結
因為大家都身處係香港, 香港一般, 唔係高速公路, 通常都只係去到60公里/小時. 高速就100 - 120公里/小時. 趕時間既就去到100(非高速), 180 - 200 公里/小時, 相信都會有的人都會咁做的.
最好換晒4條新呔
其實呢個係廢話. 不過想帶出個點係, 渣到咁上下, 最後將前呔換番去後面, 後呔換番上黎, 咁條呔會耐用左. (因前呔會蝕得快過後呔). 到時4條都可以一齊換
如果換2條既話, 因為另外個2條可能換左冇耐
平時如果你開得慢, 新呔放係後呔可能會較岩你.
反正都開得唔係好快, 好似我咁. 轉向不足(渣得太快轉彎會出現)既出現會好好好底 . 轉向過度既情況反而都有機會發生, 因為尾車太輕, 轉彎就有可能沖前
但係如果另外個2條呔其實而經好舊, 如用左3年以上, 但又覺得深紋唔想換, 咁我又會建議番新呔放前. 因為舊呔開始有機會老化, 爆呔機會大左.
平時如果你開得好好好快(其他快過我既, 我都覺得好好好快 XD , 新呔放係前呔可能會較岩你.
因為開車快更加需要前呔既控制. 因為甩尾既情況都好少見到. (當然都有機會)
所以開得快既, 就最好換晒4條呔. 正所謂, 工欲善其事，必先利其器, 頭文字D - Project D , 每場比賽都會換新呔嫁. :)))))
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It's being some time since I posted something out when I am still busy with project. The project is progressing still okay, maybe it's time to post something out.
Drivers normally put new tyres in front, and I don't really research more on this kind of thing, until when a customer told me that he wants to put the new tyres at the back, and told me that putting the new tyres at the back is safer than putting them in front (after watching a video). Perhaps it's time for me to research more about it.
Let's have a look on those videos (I have concluded the points below)
1. Michelin Tyre Experiment
http://www.michelinman.com/US/en/safe-driving/tire-safety/mixing-tires.html
2. Kumho research on new tyres to put on the rear
http://kumhotyre.co.uk/kumho-news/should-you-fit-new-tyres-to-the-front-or-rear/
3. Taiwan research (same theory as kumho)
https://www.youtube.com/watch?v=FYNU2Gtig58
5. Another taiwan news video
https://www.youtube.com/watch?v=6AyXpQBfr9c
To conclude the above why putting new tyres at the rear
A. Michelin experiment showed that putting new tyre at the front will cause oversterring / spinning when you are driving too fast while turning
B. Kumho mentions that understeering and oversteering may occur and normal handling to steer (most of the time) will not happen. If you put new tyre at the rear, when understeering happens, you can steer back to the track (when front tyre does not meet maximium grip). If the front tyre is new tyre and meeting the maximium grip, it won't be easy to turn back to the track.
Likewise, in the cause of oversteering, rear tyre have a tendency to push to the front. If you put new tyres at the rear, you will have better trip at the rear. Hence, the rear (new) tyre will not lose grip easily when braking
Furthermore, most of the cars are FWD, manufacturer setup the car to make understeering easily
To conclude putting new tyre in front
A. The technicians (in Taiwan) said that driver can have better control of the car
My opinions on the video and research
1. Michelin experiment is not persuasive enough as both experiment were not in the same driving condition (speed and control). Because the driver is asked to keep accelerating in the second round of testing, when new tyre is put in front.
If I assume the same condition, putting new tyre at the rear may cause the car to crash as well as the front tyre does not have enough grip .
2. Kumho research is easier to understand and more persuasive.
3. It's understatement that putting new tyre in front will have better control, as most of us (drivers like you) normally put new tyres in front.
Conclusion
We are in Hong Kong after all. Driver may speed up until 60km/hr (not in high way), or up to 100 - 120 km/hr (highway). Some may be in a hurry, and speed up to 180 - 200 km/hr
Change all tyres to new one
So you won't have to think much about the old ones. And the main point I want to bring out is, it's better to have your car tyres swap from front to rear, and rear to front after driving sometime, (as your front tyre will rear off faster than your rear). In this case, tyres can be used longer, and you can have all your 4 tyres changed to a new one at the same time
If you still want to change 2 tyres because the other 2 just changed not long ago
Putting new tyre at the rear may suit you if you are driving at normal speed like below 70km/h (not at high way)
Since you are not driving fast like me, the probability of understeering occurs is low. On the flip side, probability of oversteering is higher than understeering due to lighter weight at the rear.
Putting new tyre in front may suit you if you are driving fast.
Driving fast require better grip and control. Though the occur of oversteering is uncommon (in HK). And of course it still have a chance to occur
As a result, it's still better to change all your tires to new one if you are driving fast.
As the adages goes, if you want to do better things, you will require better equipment. Just like Initial D - Project D, they change all new tyres in every race. :)))))))))))
