Thursday, September 06, 2007

Too Hot to Handle (Part 4)

I finally got my disc brakes so it's time to attempt the ride down Penang Hill from top to bottom without stopping. As we learned in parts 1, 2 and 3, it's pretty impossible for a guy my size to ride down Penang Hill from top to bottom without getting a flat tire using normal brakes because the brake pads heat the rim to the point the inner tube fails.

This was a new braking system and the first time I've used disc brakes so I was a little nervous. If my brakes were to fail, I could die. My plan was to go down the hill very slowly for safety reasons and if they failed, hopefully I could jump off the bike or slide side-ways and stop or something.

Here is what the weather was like this day. For those of you who only know metric it was 26C but felt like 29C since the humidity in the morning was 89%.

If you read my last post, you know that I gave my bike a major upgrade with new disc brakes, new cranks, new sealed bottom bracket, new forks, new stem, new sealed head-set and other new stuff. Here are some pics. Notice how shiny my disc brakes are. This will change by the time I reach the bottom of Penang Hill.

My nice shiny new disc front brakes.



Shiny new rear disc brakes. Notice that it's a lot smaller than front.



Pic of my bike showing off the brakes.



Pic of my bike showing off the new cranks.



Ready to ride!



Behind me is the main Mosque in Penang. You can see rain-drops on my visor. The rain felt good.



Picture of train that goes up hill.



Packed inside train.



The view up the hill from the train. I don't ride down this. There are many other trails and roads to ride down.



The view down the hill from the train.



View from the top looking down the tracks.



The cheap rental bikes they have at the top. Instant death if you attempt to ride down the hill. Those are for riding the roads that on top of the hill.



Panoramic picture #1



Panoramic Picture #2. This is almost 360 degrees.



When I got to the top of Penang Hill, I adjusted the brakes so they were tighter than usual. I wanted maximum stopping power. I lowered my seat so I could get lower for the sharp turns. I checked my tire air-pressure to make sure it was good … then I was off down the first hill.

The first section is very steep and after 30 seconds I stopped to feel how hot my disc brake was. It was already too hot to touch even with gloves on! Now this started to worry me because if it was already this hot after 30 seconds, how much hotter would it get after 20 minutes of this. Plus I smelled something burning and I figured it was the brake pad.

I wondered if the heat of the discs would transfer to my hub and heat the grease in my hubs. I imagined the grease bursting into flames and having flames shooting out of my hubs. Flaming hubs! Now that would be cool.

I continued down the hill and I liked that the braking was silent. Normal brakes make a scraping sound and as they heat up they can screech and make all kinds of scraping noises. Well the silence didn't last long and my brakes started making a sound and it didn't sound good and it was getting louder.

I started to worry that something catastrophic was going to happen like the brake cable would get too hot and snap or the disc would warp the stop my front wheel instantly. I stopped and I could smell something burning. I touched my front disc and I saw smoke coming off the disc where I had touched it. I looked at my glove and the rubber had been melted! The finger tips of my gloves have rubber pads for grip.

I thought of pouring water on the discs but then I remembered what the guy at the bike shop said about bike parts needing to cool slowly. I had poured water on hot rims to cool them and he said I probably weakened my rims. That is true in anything really. When I was like 10 years old, I remember touching the light bulb on this lamp and it burned my fingers so I went and got a cup of cold water and poured it over the bulb to cool it down. The bulb popped and I learned that when things cool quickly, bad things happen.

My goal was to go non-stop from top to bottom but I did stop a few times just out of fear that the discs were getting too hot because the screeching noise was getting terrible. Plus I noticed that my brake cables were stretching and resulting in less braking power but I still had enough. I don't know if the heat was causing them to stretch or if it was just because they were new and that's what new brake cables do. I just wish there was a brake cable that didn't stretch. When I squeezed my brakes, it felt very spongy and soft. I want a solid feel to my brakes. I don't like the spongy stretchy feelings.

Since this is my first time getting disc brakes, I simply asked for disc brakes. I didn't ask for any type of disc brake or any brand. I know next to nothing about them. I'm sure that in the near future I will probably be upgrading my disc brakes to something more robust and I'm sure there exists cables that don't stretch.

Take my grips for example. They were always turning and slowly sliding off my bars and if they got wet, it was like they were oiled and ready to pop off any second. After asking around and trying various home-made solutions like tape and glue, I finally found these grips. They bolt onto the bars at both ends of the grip. They do not move. No matter how wet they get, they are bolted down. There is no fear of them popping off at the wrong moment (like when you're jumping off a 3-foot drop-off).

Equipment failure leads to injury and death. For example, when I'm climbing a steep hill and my gears skip, it causes me to lunge forward and I end up spraining a shoulder from the down force. I just want reliable equipment because I'm putting my life in its hands and it cannot fail. If I lose control, I could get run over by a truck. I replace my chain every 6 months otherwise it will snap before the year is up, no matter how strong the chain is.

I continued down the hill and my fingers and forearms were really hurting from squeezing the brake levers so hard. My old rim friction brakes worked much better than these disc brakes! I did notice that the disc on the front is about twice as big as the disc on the back. I figure bigger is better. Next time I'm going to get the biggest discs I can find.

I also hear there are pneumatic disc brakes. That sounds like they would work better. I don't know how they work with oil pressure but it sounds like they might have a spongy feel to them as well. Plus if the oil heats up, what could happen? I have got do more research and order the parts I need instead of relying on whatever the bike shop gives me.

Back in my teen years when I would build a BMX bike, I would order every single tiny parts down to the anodized aluminum valve caps. I knew the brand and cost of every single part on my bike. It was a custom job that I built and maintained myself. Now I have the bike shop build and maintain it and even choose which parts to put on it. This has got to stop. I need to get back to my old BMX ways and take control of my parts.

I also need to learn how to adjust gears. They come out of adjustment often and when it happens on a ride, I need to know how to fix that instead of riding with skipping gears. That's bad for the bike and dangerous for me.

I finally reached the bottom and no flat tire! I had not gone non-stop but I only stopped three times and for a very short time so it was almost non-stop. Next time I would go much faster since I now had more confidence that the brakes could take the heat.

I did notice that my shiny discs were now discolored from the heat but otherwise they seemed fine. The screeching stopped once they cooled. I had to readjust the cable since it had either slipped or stretched. I felt the hub and it felt cool. Somehow the heat had not transferred to the hub or spokes which was amazing.

You can see how the discs are discolored from the heat



My rear brake is also discolored.



So the new disc brakes were a success. No flat tires!

Side note: You may notice in the pictures that my shirts changes color from Yellow to Orange to Red. You may think these pics were taken on 3 different days but they were taken all on the same day. I bring two dry shirts with me since I sweat so much. Once my shirt gets too wet, I feel more hot because the sweat on my skin cannot evaporate because the shirt sticks to my body. Once I change into a dry shirt, I feel much cooler and more comfortable.

Heat is a big problem. I would hate to die of heat stroke. I need to listen to my body and stop in the shade and take rests and drink a lot of fluids. It may be 95 but it feels 105!

Here is what the weather was like when I returned home. It was hotter than this during the mid-day. 30C but feels like 35C.

As you can see I'm a ball of sweat basically. I drank three large bottles of water. Check out the helmet hair.

1 Comments:

Anonymous Marnie said...

Interesting to know.

Mon Nov 10, 02:47:00 PM 2008  

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