Teachable Moments from the Tour du Cafe Sunday 4 March 2012
One of the reasons I lead the Sunday Tour Du Cafe is to have the opportunity to pass on learnings to newer riders, so that hopefully they will not have to learn the hard way. I have several learnings that the group experienced during Sunday’s ride.
Jim experienced a flat, which is something EVERY rider will have. He had all the right equipment, a replacement tube, tire levers and a pump AND CO2 inflation. (Doubly prepared is not a bad idea). One of the things to do when experiencing a flat is to figure out the cause, so that the incident will not repeat in a mile or two if the offending wire/glass/protruding spoke is not addressed.
In this case, Jim hit a large bump, which caused the pinch or “snake bite” flat. The snake bite giveaway is always a pair of slits in the inner tube on the same side as the tube valve. It is caused by the rim of the wheel as the tube is pinched when the tire fully deforms as the wheel hits the bump, pinching the tube.
After the incident, we repaired the blown tube so that Jim would have a second spare, in case of a second flat. Stick-ons work, but we used the rubber cement and patch technique. First find the holes and then rough up the surface with abrasives found in the patch kit. Then apply the cement to the tube and wait for it to dry. After 5 minutes or so peel the foil back off the patch, being careful not to touch the patch surface, and press onto the newly dry cement. That’s it. Now check for leaks by inflating the tube and you are done.
CRACKS IN THE PAVEMENT
We’ve all seen them, and rolled over them and wondered what would happen if the front tire dropped in. That quest was answered yesterday, as one rider found the inch-side crack on the north side of Spanish Town road in front of the State Capitol near the curb. The wheel got stuck and the rider tried to turn the handlebars to get out of it, but to no avail. A crash resulted. The rider suffered a bumped knee (which is probably sore this morning). The rider behind (as is often the case) also crashed after hitting the downed bike of the first rider. There was a head bump (protected by a helmet), and an injured and possibly cracked lower arm bone at the wrist.
The crash was at low speed (less than 10 MPH) and speed would have contributed to more severe outcomes. 20 MPH does 4 times the damage as 10 MPH As you might remember from high school physics or drivers education: energy (and damage) is proportional to the square of the velocity.
The ride continued after assessing the injuries, and hindsight says that the best way to prevent crashes like this is to watch where you are riding, and avoid cracks in the road parallel to your path. Railroad crossings present the same hazard unless you cross them at as close to a right angle as possible, and hold the handlebar tightly to prevent the front wheel from dropping into the slot.
If you do find yourself in “the crack” the best thing to do is slow to a stop. (Easier said than done)
If you do find that the rider in front is crashing, it is probably too late to stop, and making a fast turn using a practiced “instant turn” technique is your best bet to avoid a crash. But again prevention by not following too closely is best.
The “instant turn” is from the LAB “Traffic Skills 101” class, and involves turning the handle bars BRIEFLY in the opposite direction you want to turn to get the bike leaning, then immediately turning the handlebars the other way to stay balanced in what is a very tight turn. I have used this turn when a driver pulled out from a driveway in front of me, but in order to be effective it requires that you be aware of your surroundings (no other riders, vehicles etc.) and have practiced this skill and are comfortable using it.
Regarding the helmet used in the crash, it is best to check it very carefully; as it is likely cracked (I have 3 cracked helmets from low speed fall/crashes). The rigid foam is designed to self-destruct (crush and crack) in order to protect your head. Chalk up a cracked helmet to having served its purpose, and get a new one.
Hopefully there will be more teachable moments on future rides, with less painful lessons. New riders welcome every Sunday from BUMC @ 12:00, Goodwood Park @ 12:30 and City Park @ 1:00.