Showing posts with label how to. Show all posts
Showing posts with label how to. Show all posts

February 13, 2021

Holey Spokes, Batman!

And now a few words about rim tape.

When last we left our heroine, she had safely completed her ride and traced the source of her flat tire to a gash in the side of the tube that faces the rim.

Let's take a closer look, shall we?

Where the tape should have safely covered a spoke hole, there was instead a jagged tear. The tube, regularly inflated to a high pressure, had evidently pushed the tape into the hole and eventually ripped it open.

I must admit, I have never given rim tape a second thought. Or a first thought, honestly. Its job is to protect the tube by covering the holes in the rim through which the spokes are inserted; once it's in place, it never occurred to me that it could fail. But, fail it did.

Here's a view from the flip side. We can see a slight dimple from the pressure of the tube having pushed the tape into the hole. The tape was similarly dimpled at every spoke hole, though only one had given way.

The wheel in question is a stock Mavic wheel, fitted with their stiff, woven plastic-y tape. (Or I should say, had been fitted.)

A little research and a couple of helpful YouTube videos later, I picked up two rolls of classic Velox tape at a local bike shop, removed the original tape, wiped the rims with rubbing alcohol, and applied the new tape.

Two rolls, you say? Yessiree, two rolls. One for each wheel. You didn't think I was going to risk a repeat performance on the rear wheel, did you?

And, um, if you haven't inspected the tape on your rims lately (or, ever), you might want to have a look-see.

September 15, 2014

Electrolytes

Two cyclists climbing through the desert landscape along California State Route 168 near Big Pine, California
Electrolytes. You need them.

You also need water, which is probably your first thought when you look at the two cyclists (tiny specks) in the unforgiving landscape in the photo. Water is necessary, but not sufficient, when you're stressing your body on a hot day.

Leg cramps afflicted one of those cyclists before we were eight miles into our 49-mile ride. I rooted through my saddlebag for some capsules I thought I carried for just this situation; I had none. She was able to score some electrolyte-fortified drinks and snacks from other riders along the way [but it wasn't enough].

In the heat, she kept drinking water to stay hydrated. But there is more to hydration than H2O. Water is a transport mechanism for some of the waste your body sheds, and it is key for the evaporative process that cools you when your body sweats. In both cases, you are losing more than plain water—you're losing minerals, as well. Primarily sodium, but also potassium, calcium, magnesium, and zinc.

Ever wonder why cyclists are so enamored of bananas? Potassium. In thousands of miles of cycling, I was afflicted with muscle cramps just once—on a poorly-managed charity ride, where the organizers provided only bananas at a rest stop. [Personally, I find bananas revolting.] No oranges, cantaloupe, or any other type of fruit. No potassium. A few miles down the road, my leg muscles seized up and taught me always to bring my own stash of electrolyte-laden snacks. Always. Don't count on anyone else to take care of your needs.

The biggest mineral loss in sweat is sodium, which explains that other favorite of cyclists: salty snacks. Pretzels, salted nuts, roasted salted potatoes. After a ride on a hot day, I can feel the gritty salt deposited on my skin. I have a friend who loses so much salt during a ride on a hot day that he looks like he's been dusted with white powder from head to toe.

Back to our cyclist with the leg cramps, who kept riding. Under the circumstances—in which she was ill-prepared for a strenuous ride in the heat—she should have turned back. Let me say that again: she should have turned back. We did not appreciate this, and had we insisted on it, I doubt she would have heeded our advice.

Instead she kept riding, and evidently drinking more water, further diluting the level of electrolytes in her system. When we made the final turn into the park where we began our ride, she waved us off and continued riding straight ahead. Maybe she wanted to ride around the block, or to the park's restroom, we thought. As more time passed without her return, it was clear that something had gone terribly wrong.

What we didn't know was that she had become hyponatremic. Her brain was swelling from the excess water in her system, leading to confusion. She rode another 15 miles south, where somehow she crossed paths with a kind soul who recognized that she was in trouble. He found our ride leader's phone number on her route sheet and called.

At that point, she needed emergency care; she was admitted into the local hospital. She might have died. [Yes, it was that serious.]

Electrolytes. You need them. Know your body. Find something that works for you: supplements, sports drinks, foods with salt and potassium.

And if a fellow athlete seems confused, get help.

July 29, 2013

Staying Safe

Ambulances and police officers respond to rush hour freeway traffic collision.
Last week, a raucous debate erupted on a road biking mailing list. What started it? Some close call between a cyclist and a motor vehicle. Cyclists railed about bad drivers. Drivers ranted about rude cyclists. I considered weighing in, but my comments would only have been lost in the noise. Mostly, people wanted to vent.

It's a scary world out there. How can you stay safe? Two words:
Pay attention.
Why?
People can do stupid things.
It happens. Drivers run red lights. Cyclists run red lights. Watch out for the drivers, and do not be one of those cyclists.
People can make mistakes.
I have made mistakes. You have, too. The last time I hit the pavement, two people made mistakes. I saw a colleague confidently board a shuttle bus and I chose to glide past. But she had boarded the wrong bus. Without a glance, she stepped off backward and clipped me with her enormous purse. Bam! I should not have been riding there. She should have watched where she was going.
Do not depend on the kindness of strangers.
I was stopped at a stop sign this morning, waiting for a break in traffic to turn left from a residential street onto a busier road. A driver in a pickup truck stopped, yielding the right of way to me. Would he have done the same for a car? [No.] He had the right of way, no stop sign. I imagine that he thought he was being courteous. I stayed put and waved at him politely to continue on his way. Had I pedaled forward, I risked being run down by any of the vehicles behind him. Not only did those drivers have no clue why he stopped (Planning to turn? Mechanical breakdown?), they were probably annoyed and all-too-ready to accelerate and pass him.

If you anticipate that people might do stupid things and sometimes make mistakes, you will have a safer time on the road. And instead of feeling chronically irritated, you might enjoy some pleasant surprises. Like the time a driver made a sudden U-turn in front of me, then pulled to the side of the road and rolled down his window—to apologize.

If you do have (or witness) a close call, learn from it. Is there something you might have done differently, to be safer?

Some driver made a mistake, or did something stupid, on the freeway this morning [photo above]. Two lanes blocked, multiple ambulances and police cars, a big traffic jam.
Pay attention.

July 11, 2010

Dicey Descending

This is a blind curve. What you cannot see around this bend is dangerous—the grade drops steeply into an immediate hairpin turn that hooks left.


The extra orange sign was placed to warn cyclists participating in a charity ride to slow down; normally, on this curve, it is just you and your best judgment.
Tip #1: If you cannot see around the bend, be prepared to stop.
You normally brake to reduce your speed before heading into a curve; be especially cautious when you cannot see what surprise might be lurking around the bend.

What is wrong with this picture?

Everything.

Let's start with the guy on the left. He is on the wrong side of the double yellow line. [Did I mention that this is a blind curve?]
Tip #2: Stay in your lane.
Why do you suppose he is over the double yellow line? Perhaps he noticed that the other three riders are not skilled descenders, and he wanted to pass them.
Tip #3: Do not pass on a blind curve.
Even if you can stay in your lane. You do not know what you will find around the bend. If you need to veer suddenly to your right, you will endanger the cyclists you just passed by cutting them off. If you need to veer left and there is oncoming traffic ... well, enough said.

Next, let's consider his position on the bicycle. His bike is tilted into the turn—in this case, to the right. That is good. His feet are level, with pedals at the 9:00 and 3:00 positions. That is less good. I saw this on every mountain bike heading into that curve. A mountain-biking friend tells me that this is proper mountain-biking technique, to avoid clipping a pedal on a rock, tree root, or other miscellaneous obstacle on the trail. I am not a mountain biker, and this cyclist is riding a road bike on a road.

What is the stable position on the bike, when cornering? [Hint: Did I mention that the other three cyclists are not skilled descenders?]
Tip #4: Lean your bike into the curve, with your leading (inside) knee up and your weight planted firmly on the extended (outside) leg, pedals at 12:00 and 6:00.
Your body should be nearly upright, with the bike tilted underneath you. Like the pros in this photo I snapped during the last San Francisco Grand Prix,

cyclists on our local curve need the same good form:

Think: Right turn, right knee up. Left turn, left knee up. [If you tend to confuse "right" and "left," come up with your own mantra.]

Maybe these were lucky shots, and I just happened to catch the riders' legs at a particular moment during the pedal stroke? Nope. They were all coasting downhill.

In the second photo at the top, three riders have positioned their legs exactly opposite of where they should be. What could go wrong? Well, as the bike rounds the bend and naturally tilts into the turn, they risk clipping the inside pedal (extended leg) on the pavement and crashing. Notice their upright posture. With their weight distributed through the extended leg beneath them they risk toppling over as the bike tilts. I can only imagine how unbalanced this must feel; I am not about to give it a try.

What about lane position? That guy in the blue jersey is in the middle of the road, and the guy in the white jersey is right next to the double yellow line. Shouldn't they keep as far to the right as possible, like the guy in the first photo above?

No.
By "taking the lane," they are more visible to traffic approaching from behind, and they send a clear message: It is not safe to pass us on this curve. There is no room to share the lane; you would squeeze us off the road. [They are really taking a good line through the curve, but let's call that an advanced topic.]
Bonus Tip #5: Descend at your own pace.
Your skills may not match those of the rider ahead of you; don't give chase. If you are less skilled, you risk losing control of your bicycle.
Bonus Tip #6: Before the curve, slow to a comfortable speed you are willing to carry through the curve.
You want to roll through the curve; if you grip your brakes and your wheels lock up, they are not rotating and you will skid (or worse).
Bonus Tip #7: Look where you want to go.
Your visual system is powerful. Your body will follow where your eyes are tracking. If you look at the edge of the road, guess where you will end up?