Flat tire prevention and repair by Keith A. Kenel. Presented by CSH, your community bike shop.
The only thing we have to fear…
Fear of being stranded due to a flat tire is the number two concern cyclists report as a limiting factor in riding further and/or more frequently. (Number one is fear of vehicular traffic.) I can’t conjure magical roads or trails to alleviate concerns associated with sharing the road, but I can help you learn to both prevent and quickly repair flats.
An ounce of prevention…
Pinch flats, the most common cause of flats, are avoidable nearly 100% of the time. Pinch Flats, aka “Snake Bites,” occur when tires are ridden at too low of pressure and a rider strikes an object such as a pavement joint, pothole or curb. The ounce of prevention is confirming proper inflation before setting out on a ride.
What’s proper inflation? The answer will vary on the size of the tire, the total weight the bike will be carrying and where and how the bike will be used. Smaller tires and bigger riders require higher pressure, so check your psi’s before every ride!
Your tire’s sidewall is marked with a minimum/maximum inflation range. Consider using wider tires if your bike will be carrying a heavy load or traversing rough terrain.
That ounce of prevention (28.35 grams) is only effective if administered regularly. If you want to minimize your chance of getting a pinch flat inflate your tires before every ride.
It is normal for narrow, high pressure tires to lose between ten and twenty percent of their volume weekly. A tire inflated to a safe 100 psi today could be just north of a flirting with disaster 65 psi in two weeks. To ensure that you’re not part of the Stranded Majority, then your most prudent move is to top your tires off as often as daily.
Out with the old…
Flat tire repair is dependent on minor damage to a tire. If you are riding with marginal tires you are putting both your safety and your ride in jeopardy. I can help you learn to replace a tube and be quickly and safely on your way, but you must set the groundwork for success.
Tires wear both with usage and age. Compared to fronts, rear tires wear at an accelerated rate because they hold more weight, are the bike’s driving force and are far more likely to be skidded. Many road tires have wear indicators to help you know when it’s time to re-tire your old rubber and install new. If your road tire has flattened visibly where it contacts the road, it’s time for new rubber. Likewise, if you have bulging or damaged sidewalls!
Over time, tires dry rot as the latex that binds tire threads together sublimates into the air. If your tires’ sidewalls have that coarse, rough, emery board feel, it’s time to lay them to rest and install fresh.
For want of a nail…
Don’t lose the battle because you’re unprepared; with a few easy to carry items you can continue to roll smoothly, sporting a smile on your face and feeling the wind in your (helmet covered) hair. Let’s take a quick look at what we need to keep rolling merrily along. (Boldfaced, underlined and italicized items are must haves.)
–Floor Pump for your valve type (i.e. Presta or Schrader)
-Tire Gauge (high quality pumps sport built-in gauges)
On the Go-
–Spare Inner Tube(s)
–CO2 or Mini Pump
–Bike Bag (“Burse”), Jersey Pocket or Hydration Pack
-Tire Boot (?)
-Spare Tire (???)
Floor Pump– If you own, ride, or maintain a bike a good quality pump with an accurate, precise gauge that speaks the language of your valve stem is necessity numero uno. In the US of A bike valves come primarily in Presta and Schrader. Since the turn of the century quality pumps have been equipped with heads that are bilingual and are able to inflate either traditional car-style valves or the lighter, simpler, bike style ones. Make sure to get a pump that fits your valve and your body size.
Inner Tube(s)– Size matters! Rim diameter and tire width are our must knows for tire size. Throw in valve length and we have the trifecta for tube selection. (Sure, sure, there’s tube materials as well, but what do you want for a free class?!)
Tire Levers– These rim and tire friendly pry-bars are used for removing (NOT INSTALLING!) recalcitrant tires from possessive rims.
CO2 or Mini Pump– When all is said and done, you can’t say you’re done until you pump up the jam!
BURSE!– What? You got a team car following you with your flat kit? Gotta carry your materials somehow.
Talcum powder is great for reducing friction and extending tube life, knowing how much air is in your tires is essential (BTW- your thumbs make TERRIBLE tire gauges,) patch kits are a good last defense when you’ve used your last tube and a “boot” or spare folding tire are perfect for the belt and suspender or mega-miles-from-home crowd. These italicized items are smart to own and use but not necessarily things most of us need on an everyday basis.
Give a man a fish…
Looney Tunes would start with, “Overture, curtain, lights, this is it, the night of nights! No more rehearsing and nursing a part, we know every card by heart!” So, in true, “On with the show!” presentation, let’s teach you wascally-wabbits to fish.
You can run but…
all you really need to do is get to a safe place. After initial prep, i.e., gathering your tools and remembering to carry them with you, the next thing to consider is safety. Did your flat occur in a dangerous location such as a blind-curve, just after a hill’s crest or in a locale that makes you uncomfortable? If your tire has a slow leak you can ride it a few hundred feet to safety. If you’ve had a blow-out you can PUSH or CARRY it. Remember, your safety is your concern and you can change the odds in your favor by taking an action as simple as a small location change.
Don’t talk to…
strangers! But they’ll talk to you. One of the great things about cycling is that other cyclist will offer you help. The problem is, it’s hard to tell a competent Samaritan from an all-thumbs, well-meaning, disaster meister. And, sadly, there’s personal safety involved as well. My advice? If someone offers you help always tell the noble neighbor that you have help coming but that it would be great if the bike could be fixed before that help arrives. The impending arrival of assistance is likely to ward off wolves in cyclist’s jerseys and will allow you a polite out if the well-meaning Josephine mechanic makes you fear for your BIKE’S well-being.
The wheels on the bus…
No, no. Not, “go round and round,” rather, “must come off.”
Step number one in flat fixing is wheel removal. Most bicycles are equipped with the quick release (QR) mechanism invented by Tullio Campagnolo after his apocryphal frozen fingered 1927 race debacle. These-no-tools required, wheel retention beauties are simple, elegant and, when used properly, effective.
Quick release mechanisms are usually emblazoned with the words OPEN and CLOSED. It is inarguably essential that QR’s say CLOSED when wheels are on a bike. Using a QR like a wing-nut rather than a cam mechanism is a prescription for disaster. Don’t do it!
Quick release levers use a cam to pinch a frames’ dropouts, or the part of the bike that holds the wheel. When Tullio designed the QR, one simply had to pull the lever from the closed to the open position to release a wheel from the drop out.
When retention tabs for forks were federally mandated three decades back, front wheel quick release added the extra requirement of loosening the QR by turning the threaded portion. Removal of a front wheel with safety, or “Lawyer Tabs,” requires loosening the QR sufficiently to allow the front wheel to drop out of the fork.
The number of turns required for wheel removal varies, but the magic number of SEVEN COMPLETE TURNS is usually necessary and sufficient. To remove your front wheel, open your brake’s quick release, flip the wheels QR to open and, while holding the nut of the QR, turn the lever counterclockwise seven complete turns.
Rear wheel removal is no more difficult than front. Activate your shifters and pedal your bike forwards so the chain rests on the smallest/hardest cog in back and the smallest/easiest cog in front. The gears come off with the wheel and you’ll want to place the chain back on the smallest/hardest cog in back once your repair is complete and it’s time to reinstall the rear wheel. Just put the chain on the cog, line the wheel up in the dropout and pull back slightly on the rear derailleur. With proper set-up the wheel will fall beautifully into place.
Step number two is tire removal. Sit on the ground, out of the roadway or path and away from vehicles either motorized or pedaled. If you have daytime flashing lights (YOU SHOULD HAVE DAYTIME FLASHING LIGHTS!) leave them on. They will alert fellow travelers to your presence and help remind them not to get too close.
Take a tire lever and insert the rounded section under one bead of the tire. The lever’s concave section should face the tire bead. Pry up slightly on the bead and try to rotate the lever around the rim. Many tires can be removed with a single lever, but recalcitrant ones may require the use of two levers. If two levers are needed, place the second lever about a palm’s distance from the first and pry the hooked or flat portion of the levers downward rather than trying to rotate them. When you feel the bead release from the rim then rotate the lever to the right clockwise to free the tire from the rim.
Step number three- Once the tire has been removed from the rim, pull the tube out of the valve hole and either dispose of properly or take it home to patch. (I am a pretty green fellow, but I have given up on patching narrow road tubes. The fatter the tube the greater likelihood of a successful patch.)
Step number four- Something caused your flat and, since you inflate your tires before riding, it likely was a foreign object such as a piece of glass, metal or thorn. Search the entire tire for debris. You may wish to use a glove to avoid slashing a finger. There may be multiple pieces of debris embedded in your tire. You MUST remove all debris before replacing the tube.
Check that your rim-strip is fully covering spoke nipples or spoke holes.
Make sure the hole in your tire is in the one or two-millimeter (teeny-tiny) range. If the gash is large you will need to “boot” your tire.
Step number five– replace one bead of the tire back on the rim. Note that many tires are directional. Arrows point in the direction of travel or “forward.” Cool kids put logos directly over valve stem holes. This not only looks good it also makes finding foreign debris imbedded in your tire easier by reducing your search area. Sometimes it’s necessary to inflate a tube and follow the hole to the glass, metal or cellulite marauder. Using the hole in a tube greatly reduces our search area.
Step number six– Rigatoni not fettuccine! Tubes packed in boxes are as air free as possible. When installing a tube, we add just enough air to make it grow from completely flat to barely rounded. Give your tube a single puff of life.
Step number seven– reinstall the tube beginning at the valve. Once the valve is in, work the tube inside of the tire without twisting the tube.
NOTE I- only one tire bead is installed. Be patient!
NOTE II- talcum powder reduces friction between the tire and tube. If you’re changing a tube at home, talc up. (I don’t carry talcum powder when I ride.)
Step number eight– this is when things may get difficult! Using your hands and nothing but your hands so help you dog, you must work the second bead of the tire on. Start at the valve and work your right hand in a clock-wise and left an anti-clockwise direction. The last two to six inches of bead may cause you to utter words that your mother frowns upon. The “secret” is to apply force in the proper vector, victor. Palms of hands and twisting are called for.
Step number nine– Inspect the tire and tube. Push on the sidewall and visually check that the tube is 100% inside the tire. Pay especially close attention at the valve where the tube is wider. When you are certain that the tube is 100% inside the tire and the tire bead appears equidistant around the rim commence inflation.
NOTE– I prefer pumps to CO2 because they give us more control. When filling a tire with a pump, check the sidewall after every 15 strokes or so to ensure that all is well. This will minimize the risk of blowing a tire off the rim.
Field repairs using CO2 are trickier. Do the best you can and watch for bulging tire beads.
Step number I don’t care– some people use valve collars or nuts, others valve caps, while some use both. I don’t use either. Too lazy. Your bike, your call.
Step number almost done– Put your dag-gone repaired wheel back in your dag-gone bicycle frame.
Make sure the bike is sitting fully upright and that the wheel is 100% in the dropout. Close your wheel quick releases, making sure that they are tight enough to leave an imprint in your palm. Too loose equals unsafe. Too tight and you can break the lever. Baby-bear is your friend. He likes everything, “just right.”
Close your brake quick release. Squeeze you brake levers. No rubbing equals success. If your brake rubs your wheel open the wheel quick release, make sure the bike is upright and then close it again. If the brake still rubs, then your brake may need centering. Centering brakes can sometimes be accomplished by pushing on them with your hand.
Step number last– pedal your bike onward, making sure that the gears and brakes work properly before bringing the DeLorean to that magical 88 mph.