Tuesday, July 31, 2007

Too Hot to Handle (Part 2)

I rode my mt. bike down Penang Hill again today. Penang Hill is the highest mountain in Penang. They have a train that takes you to the top which goes straight up the mountain. Last time I rode down, I got rear flat because my rim got too hot so this time I decided to try ride my front rim more to try to heat my wheels more evenly. Result: My front tire got a flat this time!

A front-tire flat is far more dangerous than a rear wheel flat. If you're traveling down a steep hill at 30 mph and your rear tire blows, at least you can still steer. If your front tire blows, you lose almost all ability to steer and brake. I'm talking from experience.

I was lucky. I passed the half-way point where you are supposed to stop and let your wheels cool. There were about 10 hikers there and it seemed like they all yelled to me as I passed. I didn't understand what they said and I kept going. My goal was to do this hill non-stop.

Then I heard a hissing noise. I stopped to see what it was, but I happened to stop next to a loud stream so I thought the hissing noise was simply the stream. I spotted this large turtle which also hissed at me. I hear there are a lot of King Cobras that like to lie in the road because the road is heated by the sun. They also hiss, I would imagine. I've heard stories about these large snakes in the road and how dangerous they are. Maybe that's what I heard? Naah.

After playing with the turtle for 10 minutes, I got back on my bike then I noticed my front tire was flat. Wow! I was quite lucky it went flat while I was playing with a turtle instead of while rounding a hair-pin turn.

This is the scary thing about rounding these turns ... you don't know if you can trust your tires. You might have sprung a leak and your front or rear tire could be really mushy so as you lean into the turn, it will won't hold you and down you go.

I've been wanting to get disc brakes but it was too expensive. My new brakes work so well, I figured I didn't need them but now I'm starting to justify the expense.

After replacing my inner tube, I continued down the hill. While I was repairing the tube, 5 hikers passed me on their way down the hill. Later I passed them but had to stop and let my wheels cool. Once again, my rim was too hot to touch, even with gloves. The hikers passed me back. Later I passed them but had to stop again and they passed me back and later I passed them again but this time I made it to the bottom so I just kept going and let my wheels cool as I rode.

With all those stops, I was descending down the hill at the same rate as someone walking down! The problem is my weight. I weight about 250 pounds. If I lost about 100 pounds, my wheels wouldn't heat up as much.

I wondered if maybe the heat was increasing the tire pressure increasing it from like 50 psi to 100 psi. I wonder if I started with like 25 psi, maybe the increase in tire pressure wouldn't blow my tire. I also wondered if it would help if I went slower. I probably get up to 40 mph then slam on the brakes to reduce to 10 mph for a turn, then back to 40 mph then back to 10 pm and so on, but I kept my speed at around 20 mph, it might generate less heat. I would generate the same heat but over a longer period of time allowing it to cool.

That's an experiment for next time.


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