Always wear your helmet
CVCer Scott Mitchell suffered a nasty crash the evening of September 3 on Westlake Boulevard near Portrero. Although Scott’s injuries included a broken nose and chipped teeth, the damage could have been much worse: Scott’s helmet (in photo, bottom) probably saved him from far more serious damage.
Here is an excerpt from Jim Doane’s account of the accident:
He was riding in the back of our six person group. David (french horn player) was the closest and thinks Scott was merging over to the left lane in anticipation of going straight at the Westlake/Portero light and he stood up on his bike and looked behind to see if the lane was clear, then his front wheel must have hit something (maybe a reflector?) and his bike went out from under him and he went face first into the asphalt.
I heard a scraping noise, looked around and he was rolling in the street so I rode back to assist.
Scott was hospitalized at Los Robles with a broken nose, chipped teeth and serious facial abrasions. After returning home over the weekend, Scott was well enough to send this update on his condition:
[My wife and I] want to make sure we thank all of you who have sent emails, texts, and/or visited me during my stay in the hospital. All of your well wishes, thoughts and prayers are greatly appreciated and I’m sure speeded up my return home.
Although I was able to get up and move around on my own in the hospital room, getting rid of the IV, putting on real clothes and getting outside was delightful. As we all know being home makes everything feel better. So I’m now impatiently waiting for everything to heal and most of all for the swelling in my lips to go down – for those of you who have seen me you know what I mean. For the rest of you the best way I can describe the swelling is to say it’s cartoonish – Angelina Jolie’s lips look pencil-thin compared to mine.
Still eating through a straw or with a spoon after the blender as the facial fractures make it almost impossible to chew. I’m puttering around the house doing non-strenuous ‘honey-dos’ I never seem to get to, but I already miss riding. Sigh.
I checked over all my bike gear. . .The biggest discovery is that I did indeed hit my helmet on the ground. The very front of the helmet (that goes across the forehead) has scrapes, the the styrofoam is compressed to less than half its normal size, about 1 1/2 inches either side of center, and there is also a crack in the compressed section.
So despite the trauma to the rest of my face, things would have been a lot worse without a helmet as it’s evident the helmet absorbed a significant portion of the impact.
…I’m forbidden from any exercise more strenuous than sweeping the floor until after getting my nose repaired, which is still a week away. And I won’t be cleared for any activity that could potentially reinjure my face for at least six weeks after that. So right now the earliest I’ll be able to take the training wheels off looks like October 26th….At least I’ll be able to ride again eventually.
I keep reminding myself that it could be a lot worse or longer.
As J.C. always says “Keep the rubber side down” – I highly recommend that.
Scott is one of the CVC’s strongest riders. We wish him a speedy recovery!
Car doors and cyclists
Rear Lights – Flashing or Solid ?
Have you ever heard of “The Moth Effect” ?
Studies have shown drunk, drugged, elderly and fatigued drivers drivers sometimes are attracted to blinking lights and drive towards them. This is one of the reasons that The California Highway Patrol generally WILL NOT leave their overhead flashing amber rear lights on when they have pulled a motorist over on the freeway.
So why do we as cyclists feel it is safe to ride with flashing lights ourselves? Maybe it isn’t too safe after all. Leaving out lights on solid may be safer in the long run.
An article located at http://www.policedriving.com/article145.htm quotes,
“The knowledge of human perception calls into question the use of red warning lights when the vehicle is parked in or next to the highway. Instead of warning people away, the red emergency lights actually draw drivers towards the lights. This so-called moth effect refers to “a state of narrowed attention associated with excessive concentration on some object or task with the resulting in a loss of voluntary control over response.” People drive where they look! Drugged, drunk, elderly and fatigued drivers will drive right into the rear of the vehicle in the road and drive off the road to hit the vehicle parked on the shoulder that is displaying the red warning lights. This happens more than we like to admit. How many close calls have you had?”
Further information can be found here, http://www.sunguide.org/docs/trafficincident/How_Effective_are_Flashing_Lights_Stopped_on_the_Road_Shoulder_012002.pdf
Food for thought……. Stay safe out there!
Tire Inflation Information
Rolling resistance is one of the most misunderstood elements of the bike. There will be those who insist that reducing it is all about running super-high tire pressure. That is simply not the case.
Rolling resistance is dictated by several factors, one being tire construction. A top-quality clincher tire will have a threads-per-inch count ranging from 125 tpi to an astounding 440 tpi. Most companies use nylon for casing threads, going by names such as Aramid or Polyamide.
There will be 3-5 overlapping casing layers to give the tire strength, puncture resistance and good handling characteristics. The suppleness of the casing material is key to performance and reducing rolling resistance.
Another factor is the tread material. Most top-end clinchers are now using some form of silica compound, which lowers rolling resistance while increasing cornering traction. Sounds like magic, doesn’t it?
Understand that the designers and engineers behind quality tires are some of the brightest lights involved with the bike industry. We are spoiled riding tires that are as good as the stuff used in auto and motorcycle racing, yet we can buy them for just $50.
Remember this: The best tires cost what they do because of the technology and materials that go into making them. We are the lucky beneficiaries of this high science.
The last factor affecting rolling resistance, obviously, is tire pressure. If a tire is flat, it has a whole bunch of resistance and really doesn’t handle very well.
A properly inflated road tire (700x23C) at 6bar/87 psi has about the same rolling resistance as the same tire at 8bar/115 psi. But at the higher pressure, the rider gives up some of the cornering traction and comfort so necessary to cycling.
There’s a perception that running tires at 115-140 psi somehow makes a rider faster. What those maximum pressures really do is accelerate wear, compromise handling and give an extremely harsh and skittish ride.
Super-high pressure also compromises the integrity of your wheels and, in the case of a high-speed blowout, can assure you of a visit with the pavement. Heavy braking while descending will heat the rims and increase pressures well beyond the danger zone.
I’ve talked to pros about tire pressure. They universally agree that inflation to 85-100 psi is plenty, depending on road conditions. Pressures up to 110-115 psi are fine on a smooth time trial course without many corners.
Most riders who run super-high pressure will remain unconvinced about the benefits of lower pressure. I think it’s their placebo.
Lance Armstrong only runs something like 105 psi in his front tire, so there goes the high pressure argument!
From We Keep You Cycling / WKYC Original Content – http://www.wekeepyoucycling.com/en/t-tirepressure.aspx
“Tires are rated by their manufacturers with a recommended and maximum PSI [pounds per square inch] inflation rating. For the purposes of this discussion, the focus is on maximum PSI inflation.
The maximum PSI rating of a tire does not suggest that inflating one additional PSI over the maximum will result in the tire blowing off the rim. It does, however, indicate the strength of the bead, while concurrently maintaining a buffer for pump gauge variance and rider weight.
In recent years, cyclists have pushed for higher PSI tires, thinking that more tire pressure converts to a faster bike. In a fashion they are correct. The greater the PSI, the less the tire is in contact with the ground which translates to less rolling resistance. However, less tread on the ground also means reduced cornering and braking performance as well as reduced comfort. One could argue that being comfortable on the bike might be equal to, if not more important than, the SMALL reduction in rolling resistance gained by higher tire PSI.
Where the Rubber Hits the Road
For the average cyclist, PSI is determined by ride comfort. A 170-pound rider on a 120-PSI rated tire can inflate tires to 80 or 90-PSI, or go up to 130-PSI. The risk of a problem is minimal; however the risk is not zero. As the 170-pound rider on a 120-PSI rated tire goes from 80 to 130-PSI there is a corresponding reduction in tire contact on the road, decreasing breaking and cornering performance while slightly increasing speed.
For a lighter weight 130-pound cyclist riding on tires at or above the maximum PSI, the ride can be noticeably uncomfortable. The same tire that bulged a little under a 170-pound cyclist, will stand tall for a 130-pound cyclist, with no give to imperfections in the road. Ride quality, as well as braking and cornering performance, is diminished. Reducing the PSI to the point where the tire has a slight bulge when ridden, will increase comfort and performance.
Heavier 200-pound-plus cyclists have less tire PSI flexibility. There are no hard and fast rules. Going beyond the manufacturer’s rating becomes a personal experiment. One could view the maximum PSI as the not-to-exceed limit. The consequences of inflating and running on tires at 120% of the maximum PSI are not documented. Tire size and rider weight are just two factors to gauge maximum PSI. Some heavier riders need to run at, or slightly above, the maximum PSI to reduce pinch flats. (See “Avoiding Flats” for more on pinch flats.)
Something to Consider
When inflating tires, the PSI on the pump gauge does not include the cyclist’s weight. PSI increases with a rider seated on a stationary bike and spikes when riding. Changes in PSI are caused by bumps, potholes, changes in altitude, heat and an occasional bunny-hop. One of these factors in isolation is not likely to cause a problem, but when pushing limits on the bead, they all become factors of potential failure. All are worth consideration when inflating tires over the maximum PSI.
We Keep You Cycling recommends running at or below the maximum PSI rating of the tire.”
Only the intercepts change for tires between 20-28 widths. Larger widths and the slopes change. Obviously these are generalized and assumed to be linear. While not 100% correct they will give you a great place to start.
Tire Width=20: Pressure(psi) = 0.33 * Rider Weight in lbs + 63.33
Tire Width=23: Pressure(psi) = 0.33 * Rider Weight in lbs + 53.33
Tire Width=25: Pressure(psi) = 0.33 * Rider Weight in lbs + 43.33
Tire Width=28: Pressure(psi) = 0.33 * Rider Weight in lbs + 33.33
Tire Width=32: Pressure(psi) = 0.17 * Rider Weight in lbs + 41.67
Tire Width=37: Pressure(psi) = 0.17 * Rider Weight in lbs + 26.67
Example: You are 150lbs running 28′s
Pressure (psi) = (0.33*150) +33.33 = 82.83psi (rear)
Front Pressure = .9*Front Pressure = .9*82.83psi = 74.55psi front
You could start by running 85 rear 75 front and adjust from there. For your weight I would step down to 23′s which you could run at 92F – 102R. That would be nice and comfortable and have less rolling resistance than the 28′s.
Thanks to We Keep You Cycling – We Keep You Cycling and cycling connoisseur Herb M. for providing information for this article. Some of the information provided comes from our friends (as well as Uncle AL) at RoadBikeRider.Com
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