Imagine this: Your chain is hanging down like a wizard's sleeve and you want to tighten it. You lay out your tool kit, hit your favourite music on Spotify and whistle along to it.

You slip the wrench onto the nut. But it won't budge. It's ok, let's pull harder, you say. But it still won't move. Not even a micrometer.

So you now have to contort yourself all over the bike to get better lever. It still doesn't move. It felt like the nut might as well had been welded on.

Now, as sweat pours off your brow, you resort to hammering on the shaft of the wrench. Nope. Nothing's happening. So you stand on the wrench. The nut suddenly began to move and your foot slips off it as you almost hit the ground, and all sorts of swear words known and unimaginable are heard by your neighbours.

Is this another of my writer's imagination gone wild? Unfortunately, no. It just happened to me this morning.

What cause it?

The answer is simple: The so-called mechanics in most workshops, except for a very few, have a love affair with the pneumatic impact wrench, or more popularly called the air gun.

19mm nut? Air gun. 14mm bolt? Air gun. The lazy buggers would even use it on 10mm bolts. I sometimes wonder if they use the gun on their partners, too, FFS.

They simply do not understand that different bolts and nuts for different applications have different tightening torques. For example, the the rear axle nut is usually requires between 90 to 110 Nm, depending on the size of the bolt, which usually also depends on the size of the bike. The 14mm bolt holding the rear brake caliper bracket of a Yamaha Ysuku needs just 39 Nm. And yet they'd KLAK KLAK KLAK KLAK KLAK on these fasteners unscrupulously.

Thus a 15 minute chain tightening job became 1 hour... And that's without breaking a bolt or nut!

I've experienced a bike's rear axle bearing breaking during a ride, which resulted in the bike riding sideways like a crab too, because the nut was overtightened with a pneumatic wrench!

So, what's the solution?

My first solution is to frequent a workshop that observe correct workshop practices, such as using a torque wrench. (There are two I usually go to).

Secondly, if you don't fancy so, buy yourself a good torque wrench. They aren't so expensive. Only caveat is you need to take good care of it.

So, if I visited a workshop due to an emergency or other situations and they used the pneumatic wrench, I'd loosen the fasteners and retighten them to the correct torques.

Tips on using the torque wrench

1. CLICK or KLAK ONLY ONCE. I repeat: ONLY ONCE. Clicking once means you have reached the desired tightening torque. Clicking more than once means you are introducing more than the desired torque. I learned this directly from a German engineer while working for Mercedes, who gave me an effing in front of everyone on the workshop floor which I will never forget. Checking this with other qualified engineers confirmed this.

2. DO NOT drop or throw the wrench around. You may damage the internal clutch and it will have different torque readings after that.

3. DO NOT use it to loosen fasteners from the beginning as you may damage its internal clutch. You ought to use a normal wrench to first loosen a fastener, then continue with the torque wrench if you so wish because it has a built-in ratchet.

4. Set the torque back in the lowest setting and store the wrench to maintain the spring's strength.

5. Store it in the case that it came in.

Minyak brek atau lebih tepat, bendalir brek (brake fluid) merupakan "darah" di dalam sistem brek.

Namun, ia merupakan antara barang gunaan yang paling diabaikan. Ini kerana penurunan prestasi brek terjadi secara beransur-ansur dan sistem brek, khususnya piston dalam kaliper yang dapat melaras diri untuk lebih dekat kepada cakera brek mengikut ketebalan pad brek. Oleh itu, kita merasakan seperti brek kita berfungsi secara normal...

Apa yang akan terjadi jika saya tidak tukar bendalir brek langsung?

1. Jarak membrek akan jadi lebih jauh

Walaupun kita rasakan seperti tiada pengurang prestasi membrek, kita sebenarnya memerlukan jarak yang lebih jauh. Kita mungkin tidak perasan tetapi ia akan menjadi nyata apabila kita membrek secara mengejut.

2. Tuil brek rasa "lembut"

Tuil brek akan terasa seperti "lembut" apabila kita membrek dengan lama atau lebih kerap, khususnya di dalam bandar atau ketika menuruni cerun yang curam seperti daripada Genting Highland atau Cameron Highlands.

3. Kehilangan brek atau brek melekat

Dalam kes yang ekstrim, bendalir brek akan membentuk gam. Cebisan ini boleh tersumbat di dalam lubang-lubang halus di dalam sistem brek dan tidak membenarkan bendalir brek untuk mengalir dan ini menyebabkan brek motosikal tidak berfungsi.

Ia juga boleh tersumbat dan tidak membenarkan bendalir brek mengalir semula ke pam brek. Jadi, maksudnya brek kekal melekat!

Ada juga kes di mana cebisan-cebisan ini tersumbat di dalam pam ABS dan merosakkannya. (Harga pam ABS mahal nak "mamp" taw...)

Kenapa terjadi begitu?

Bendalir brek sebenarnya diperbuat daripada glycol. Ia merupakan cecair yang dapat menyerap haba yang banyak dan melepaskannya kembali dengan cepat. Tetapi masalahnya glycol ini gemar kepada air dan dapat menarik wap air daripada udara sekeliling. Wap air ini kemudiannya tercampur di dalam bendalir brek itu.

Bendalir brek DOT 4 yang baharu dan tiada wap air di dalamnya mempunyai tahap didih sekitar 260 darjah Celsius. Ini dikenali sebagai tahap didih "kering" sesuatu bendalir brek.

Tetapi air mendidih pada 100 darjah Celsius. Justeru tahap didih untuk bendalir brek akan menjadi rendah apabila terdapat wap air di dalamnya. Bagi mendapatkan piaiwaian DOT 4, tahap didih "basah" sesuatu bendalir brek diukur dengan kandungan 3.7% air di dalamnya, sama seperti kegunaan untuk 2 tahun. Tahap didih ini sekarang jatuh ke sekitar 165 darjah Celsius.

Itu baru sahaja 3.7% kandungan wap air, dan tahap didih bendalir brek sudah jatuh sehingga hampir 100 darjah Celsius! Bayangkan berapa banyakah kandungan wap air di dalam bendalir brek yang lama tidak ditukar!

Tambahan lagi, bendalir brek tidak menyerap haba yang lebih tinggi kerana sudah mencapai tahap mendidih terlalu awal, dan ini akan menyebabkan kehilangan tekanan kepada piston brek. Kerana inilah jarak membrek jadi lebih jauh.

Apabila wap air mendidih, gelembung udara akan terbentuk di dalam paip brek. Ini akan menyebabkan tekanan brek tidak sampai ke piston kaliper brek. Oleh itu, tuil brek terasa lembut.

Jadi, berapa kerapkah saya kena tukar bendalir brek saya?

Setiap 2 tahun, tidak kira berapa jarak yang anda telah bergerak, mahupun jika bendalir brek masih kelihatan "cantik." Perihal ini ada tertera di dalam panduan pengguna motosikal anda.

Bendalir brek gred apa yang harus saya pakai?

Kita akan cerita panjang lebar mengenai ini di dalam bahagian depan, jadi jangan ketinggalan.

The world renowned exposition of all things custom art and culture, Art of Speed (AOS) returns after a two year hiatus in Malaysia. It will be held on 2nd to 3rd July 2022 at the Malaysia Agro Exposition Park (MEAPS), Serdang from 10.30am to 8.00pm on both days.