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Showing posts with label tire pressure. Show all posts
Showing posts with label tire pressure. Show all posts

Tuesday, June 15, 2010

Mid Town Alley Grand Prix, (AKA The Hipslapper)


[Special Note:  I have a "Music Player" gadget, 4th down to the right. You may run audio from it or the video as you see fit by pausing the music player or muting the embedded video. Enjoy!]
I just received the following questions from a concerned reader:


"How was everything after the crash?
Bike?
Body?
Pride?"

On the first one:  Pretty good.  I popped up immediately and saw bike racers coming at me and I sprinted (as best I could in cycling shoes on wet pavement) to get off the course.  It was a close one! 

On the second one:  I surveyed the bike and found it to be entirely intact with the exception of the new handlebar tape and a tiny bit more saddle abrasion on it's sliding edge.  Oh, and I lost a water bottle down a storm drain.  It was as if my bottle said, "I've had enough of this crap.  I'm getting the hell out of here now!"  It skidded across the wet pavement and went directly down into the mouth of the storm drain.

On the third one:  I landed on my left side which  was unfortunately  the same injured side from the week before.  My skin is still growing back from that one.  A couple of spots are still tingling and burning a bit.  Happily they are unaffected.  The bulk of my impact was absorbed on my rear/hip.  I received almost no road rash.  Only my coccyx hurts a bit and the styloid process of my left foot.  Both are minor injuries and just like Wolverine I will regenerate (just not as quickly).

Lastly:  I don't feel too bad about the crash.  I of course wish it didn't happen.  The absolute best thing is that I didn't take anyone else down.  To me that is the most important thing....... well that and not getting seriously injured....... oh, and not destroying my bike/wheels. 

I sorta regret not finishing the race, but not much.  I easily could have taken a free lap and gotten back into the race.  I debated that for several seconds.  On one hand it would be brave to jump back in and finish.  Some people believe that it is good for a racer's psyche to immediately get back on the bike after a crash.  I do not disagree with this, but often crashed rider's are more likely to crash again because their confidence is also damaged. 

I decided not to continue racing for several reasons.  I didn't want to press my luck.  I was basically ok and I hadn't caused anyone else a crash.  I didn't expect to do well in a rain race even before a crash, and now I would be worse off.  Plus I had an 89 mile professional race the following day.

I was extremely surprised that I had crashed.  I did not expect it at all.  I've gone through countless corners at higher speeds, during which I was almost sure that I was going to go down hard, but didn't.  Crashing unexpectedly shakes my confidence a bit.  Happily I have it on video and I can study the elements of the crash.  I believe that my mistake was applying too much torque while beginning a turn.  My rear wheel broke traction and instantly laid me and my bike down.  Solution:  don't pedal through wet turns.

At any rate, I'm fine and my racing will continue.  I think that the best is ahead of me, in fact.

I did want to mention that I was running 100 psi in both my front and rear Vittoria Tubulars on Zipp 404 wheels.  I should have run my tires at 85/95, due to the conditions, but most importantly I should have not been trying to pedal into the corner that I went down in.

Below is some supplemental information from Thomas McDaniel concerning cornering and correct tire pressures for racing.  Thomas is currently working on his Master's in exercise physiology and most importantly was a professional bike mechanic for the Pro-bike racing team, Jelly Belly.


"Thomas McDaniel June 2 at 3:24pm
Dave, I read your blog about cornering and felt compelled to add commentary. You make reference several times about keeping weight over the center of gravity, but then later add to point the knee into the turn, which in fact moves valuable weight outside the center of gravity (or more importantly, away from above the contact patch of the tyre). The reason pointing the knee towards the inside of a turn helps is because it facilitates the hips rotating, which guides you through a turn. Bicycles are steered with hips, not hands. Unfortunately most cyclists are so tight through their hipflexors they cannot keep their knee above the tyre while rotating their hips into the turn, thus losing the benefit of additional weight atop their contact with the road.
As for other ideas....tubulars are not meant to be run @ highest of pressures. In fact, I would run tyres for the team @ 90 front and 105 rear on techincal courses like Downers Grove, but only 85/95 if raining. My riders absolutely loved it, and rarely crashed because of it. The supple nature of the pressure allows the tyre to soak up lots of the effects of cornering, and keeps the tyre consistently in contact with the road, which is great for high speed cornering and power transfer. The energy potentially lost is neglegeble compared to the security and performance of properly inflated tyres. Keep in mind, this is from 284 days of racing with 9 bikes worth of tubulars per day. Never a rolled tyre, and significantly fewer punctures and crashes, especially in wet conditions."

Lastly, I briefly encountered Brad Huff    while warming up the following day at the "Tour de Grove" and expressed that I was having trouble cornering.  He said shortly, "Push down hard with the outer leg", and  that the previous race (the one in this blog, WHICH IS THE ONE HE WON, BTW) was "ok, you just couldn't pedal through the corners."

Wednesday, April 28, 2010

The Delmarvelous Criterium



Hello race fans:  This race was actually fun.  Click this to get in the spirit of the event.  I don't have a lot to add to my race video.  I did decide to fade out the audio and put in my musical creation.  Primarily because the chatter noise was so loud and annoying.  Plus, I actually like my little musical piece.  Someone gave me a little encouragement so what the hey, why not. (don't worry, I'm not going to start singing). [Use your inner DJ to select music from the music player on the sidebar and mute it and/or the video's audio icon.]

Ok, so I promised to dish out a little wet weather advice that I have learned over the years.  Here's possibly one the best ones:  In order to dry your shoes quickly use newspapers.  Simply ball the sheets up and fill your shoes up.  The capillary action of the paper will quickly dry your shoes out.  After a few hours pull out the paper and allow to air dry.  What?  You already knew that?  Damn.

How about this little ditty:  Another drying trick was given to me recently by my friend Charles Gentry.  This is good for all sorts of drying needs, including removing water that is trapped in your carbon rims (if you have them).  Charles says, Let the "air out of the tube and get a desiccant pack from Walmart.  Comes in a cup and you take the lid off and put the rim and the frame (oh yeah, bike frames too) in a large trash bag with the open cup of desiccant.  Soon the cup will fill with water and you pour it out.  The desiccant will suck out the moisture out of the air in the bag and in the rims and frame.  This is the easy way.  I raced in Hawaii for 5 years and this is what we did."

It is also important to not fully inflate your race tires, in particular the front.  Instead of the standard 120psi, try 85psi for the front and 95psi for the rear when using tubulars (consult the manufacture's instructions for clinchers).  This is most important on the front tire.  You can slide the rear a bit and usually recover, but you will almost never recover from a front wheel slide.  Where the front wheel goes, so does the bike.  Typically racers take the first corners tentatively and progressively get faster.  The last corners before the finish often have wipe outs. (for information concerning high speed cornering see my post on the topic.)

That leads me to the single most important rule of bike racing and general group riding (rain or no rain).......NEVER HALF WHEEL!  Basically, half wheeling is the potentially dangerous and foolish practice of positioning a bicycle such that a rider's front wheel crosses the plane of the rear wheel of the rider in front of them.  If the front rider swerves suddenly on purpose (say.... to avoid a pot-hole or a dead aardvark) or accidentally (say..... because they noticed some discarded porn in the ditch)  they can sweep the front wheel of a rider that is half wheeling.  Again, as we have already learned:  where the front wheel goes, so does the bike.  Half wheeling is probably the most common cause of bike crashes and is most common when the pack is bunched up and not going very hard. That's one of the reasons why I say that fast races are safe races.  When it is super fast, there is no half wheeling.  And if someone crashes in a corner, they are usually sweep off the course by the pure momentum of their trajectory.  As Martha Stewart says:  "It's a good thing!"

For information concerning biking and racing safe see my post on the topic.

Well, that's enough dude and dudettes.  Enjoy your you know what.  (bicycle)

 To learn about the best video camera in the world for videoing cycling (which is the cameras that I use for my videos) click here.