How to Increase Bicycle Wheel Efficiency

To increase bicycle wheel efficiency, there are several factors to consider. Here are some tips to help you improve the efficiency of your bicycle wheels:

1. Proper inflation: Maintaining the correct tire pressure is crucial for optimal wheel efficiency. Underinflated tires increase rolling resistance, making it harder to pedal. Overinflated tires can negatively impact traction and ride comfort. Consult the recommended tire pressure range imprinted on the sidewall of your tires and use a reliable pressure gauge to ensure proper inflation.

2. Lightweight wheel components: Lighter wheels can enhance overall bicycle performance. Consider investing in lighter rims, spokes, and hubs. However, bear in mind that excessively lightweight components can compromise durability and strength, so it's essential to strike a balance based on your riding style and terrain.

3. Wheel truing: Ensuring your wheels are properly trued is essential for efficient cycling. Truing involves adjusting the tension of the spokes to eliminate any wobbles or hops in the wheel. A true wheel minimizes friction and allows for smoother and more efficient riding. If you're unfamiliar with the process, it's recommended to have a professional bike mechanic perform the truing.

4. Bearing maintenance: Clean and well-lubricated wheel bearings reduce friction, enhancing wheel efficiency. Regularly inspect your wheel bearings for any signs of wear or roughness. If necessary, clean them with a suitable degreaser and apply a quality bicycle bearing grease to keep them running smoothly.

5. Aerodynamic considerations: Reducing wind resistance can have a significant impact on wheel efficiency, especially at higher speeds. Consider using aerodynamic wheel designs with deep rims or disc wheels, which can enhance airflow around the wheels and reduce drag. Additionally, wearing more aerodynamic clothing and adopting an aerodynamic riding position can further optimize efficiency.

6. Brake adjustment: Properly adjusted brakes can prevent unnecessary drag on the wheel. Ensure that your brake pads are properly aligned with the rim and don't rub against it when not engaged. Adjust the brake tension and cable position as needed to achieve smooth and efficient braking performance.

7. Rim tape and tire choice: A well-installed rim tape protects the inner tube from spoke holes and irregularities in the rim bed. Make sure the rim tape is correctly positioned and free from any bulges or gaps. Additionally, choosing tires with low rolling resistance can significantly improve wheel efficiency. Look for tires specifically designed for fast and efficient riding.

8. Wheel maintenance: Regularly inspect your wheels for any signs of damage, wear, or loose spokes. Ensure that all spokes are properly tensioned and tightened. Keep an eye out for cracks or dents on the rims, as these can compromise wheel strength and efficiency.

Remember that improving wheel efficiency is just one aspect of enhancing your overall cycling performance. Factors such as bike fit, pedal technique, and overall fitness also play crucial roles. Additionally, it's important to consider the specific terrain and riding conditions you'll be encountering, as wheel efficiency requirements can vary accordingly.

Schrader Vs Presta Valves

If you read my post about Bicycle Mechanics in Leaside Toronto then you know I purchased two things today: #1. A Presta-Schrader valve adapter, and #2. a bicycle pump that is compatible with both Schrader and Presta valves.

I already have a Schrader bicycle pump, which is pretty standard. But I didn't have a working Presta one so I decided to get a new one (that works) and in the event it ever breaks and I need an adapter, I therefore bought an adapter too. I call it the Mechanic's Rule of Tool Redundancy - when in doubt, get two or more in case you cannot find the other tool, it breaks, or cannot be used for whatever reason. This is why you can never have too many toolboxes, screwdrivers or tools in general.

Since the invention of the pneumatic tire many valve types have come along but for bicycles the two most popular that are still in use are Presta and Schrader (or as I like to call them, de French one and zee German one - not because that is their country of origin, just because they sound like they are French and German).

The Presta valve is the skinny one of the two and is slightly more cumbersome to use, having a lock nut instead of a spring to make sure it is closed and doesn`t leak air. The Presta valve is more popular on racing bicycles because it is skinnier and doesn`t leak air easily.

The Presta valve also enabled racers to inflate tires with a simple pump with attached chuck (pump head) and no hose. Having no valve spring to overcome it is therefore faster and easier to pump gas into the tires. If Schrader valves had a valve depressor it could speed up the process, but it would make the pump head larger, heavier and impractical.

Because of the small diameter of the Presta valve it requires a smaller hole in the rim, which means that the bicycle rims can be narrower. This saves on weight and increases overall speed.

However Presta valves break easier, are harder to fix, are not widely used except in racing bikes, and Presta pumps break easier too (based on my first hand experience with them). Some Presta valves have been made with removable cores to make them easier to fix, but demand is so small that they are uncommon. Removable Presta cores can be identified by two wrench flats on the coarse valve cap threads.

In contrast Schrader valves are robust, universally used, and have an easily removable core. And they are easier to fix. Spring closure makes them simpler to use because one needs only to press the inflation chuck onto them at any gas station that has an air pump. With foot or hand pumps, a screwed or lever chuck provides the valve depressor - and it can tell you what the pressure is in the tire too.

My advice for my fellow bicycle mechanics? Get a Schrader pump and a Presta adapter. You might never use the Presta adapter, but at least you will have it when you need it.

When NOT to Repair a Bicycle

By Smokey Dymny from the Quadra Bike School

Some home-based bicycle mechanics like to “repair” an used bicycle for resale. Before you start down this path make sure you are able to assess an used bicycle’s potential.

1.) WHEEL TRUING

The wheels must be able to be trued and YOU have to be able to do it. It costs too much to pay for this repair. Check if the spoke nipples will turn with the proper size of spoke wrench (you need to have the red and black spoke wrenches at least). A spoke gauge would be handy too.

It’s best to UNWIND the nipples rather than tighten them, so you don’t get blamed for wrecking the wheel if a spoke should break from tightening. If most of the spokes will turn, then you can oil all the spoke nipples and maybe true up the wheel at home. I say MAYBE because you also need to check the wheel rims for dents, which may prevent you from making the wheels workable.

Also spin the axles with your fingers to assess how badly worn or pitted the hubs are – you need to have the hubs turn smoothly for proper truing and for riding. Finally, if the rims are alloy, place a small straight edge across the sidewall (braking surface) to see if the brakes have worn the sidewalls down. If there is a 1mm gap between your straight edge and the rim there is too little metal left in the rims for the wheels to last. Braking will soon wear right through the rim and the tube will burst through the weak sidewall.

If all these things check out then you need access to a community bike shop to use their truing stand to straighten and tighten the wheels properly.

(It also possible to purchase a truing stand, but its a tad out of reach unless you have the funds to do so and plan to be truing wheels regularly.)

2.) BRAKES AND SHIFTERS

If the wheels pass inspection check the brakes and shifters to see if they will operate from the controls. If they do – good. If they don’t, disconnect the brake and shifter cables and see if the brakes and shifters move well on their own. The problem could just be rusted cables and housings, which you can replace.

3.) CHAIN STATUS

You need a chain checker to assess if the chain is worn. Most mechanics call this chain “stretch”. Of course if the chain’s rusted, you should just toss it anyway - a rusty drivetrain is a major loss of efficiency on a bicycle.

4.) TIRE WEAR

Check the tires for cracks and wear. If they look like they have tread, let out the air and pinch them till you see into any cracks. If the tire casing (white cloth) is visible at the bottom of a crack, the tire is crap. Also check for wear and cracks on sidewalls. Maladjusted brakes may have destroyed those too.

5.) HANDLE BARS

Finally check the headset (steering) and crank rotation for looseness or rust and corrosion, these symptoms will indicate you have to replace the ball bearings inside it.

6.) FORK STRAIGHTNESS

Check if the front fork has been crashed. A straight-edge held along the steerer tube should continue in a straight line down the fork till it begins to bend forward. You can eyeball the frame for straightness front–to-back or, better yet, tie a string to one rear drop-out, run it around front steerer tube and back to the other rear drop-out. Then check that the distance from this string to the seat tube is the same on each side. This only sounds tricky till you try it in practice.

7.) FINAL ANALYSIS

If you can fix all the problems you have analyzed, then buy the used bike but point out all its problems to the owner to bring down the price. If the bike has ALL the above problems, even getting it for free may not be worth it, unless the frame is really, really good.

Don't waste your time on a bicycle with a crappy frame if it has lots of problems with its parts that need repairing or replacing.

8.) PRICING

Estimate how much you can sell the bicycle for after its been fixed. Your selling price should cover your new parts and a reasonable charge for your labour.

Mending a Punctured Tire Tube

Tube punctures are the most common form of a breakdown and it is really easy to learn how to mend them.

#1. Release brake calipers and remove the wheel.

#2. Use tire levers (available from bike shops) to remove the tire treads.

#3. Carefully run your fingers around the inside of the tire tread to check for sharp objects, such as nails, splinters of glass or thorns. Remove the cause of the puncture and check that there are no more spikes in the tire.

#4. Find the hole in the tube, either by pumping it up and holding it under water to look for bubbles, or by feeling for escaping air. There may be more than one hole so check carefully.

#5. Mark the hold with pen or chalk. Use sandpaper or the scratcher from the puncture repair kit to scuff the area around the hole to help secure the glue to the tube. DO NOT USE A WIRE BRUSH!

#6. Spread glue thinly and evenly over and around the hole or holes in the tube and wait for the glue to dry until it feels tacky to touch. Place a patch over the marked hole and apply pressure. (A faster alternative is to use the new glueless patches.)

#7. Lightly pump up the tube. Place one edge of the tube around the wheel rim and push the tube’s valve into the rim’s hole. Starting from the valve, push the rest of the tube into the tire treads. Ensure the valve stem is perpendicular to the rim and that the tube isn’t twisted. Once the tube is inside the tire, begin to place the second edge of the tire onto the rim. About 75% of the tire will go on easily, the rest will need strong fingers or the tire levers to coax it onto the rim. DO NOT PINCH OR DAMAGE THE TUBE! When done, pump a little more air into the tube and check that the tube isn’t caught between the rim and the tire.

#8. Slide the wheel back into place on the bike and tighten the bolts gradually, ensuring that the wheel remains aligned straight to the frame. Reconnect the brakes.

#9. If you are happy with it, fully pump up the tire. Take the bike on a short ride, and test that the brakes are still working correctly.

On long journeys carry a spare inner tube and the necessary tools with you. Its faster to just replace the tire and mend any punctures later when you get home.

Why do my tires leak during the winter?

By Smokey Dymny, Veteran Bicycle Mechanic and Teacher
Quadra Bike School

Yes, spring’s just about here and you’re ready to ride again. Before you pump up your tires, let’s check a few things first.

You may be asking "Why are these tires so soft when the bike sat still all winter?"

The answer is: rubber always leaks whether you are riding or not. If your tires are completely flat you may have to check the tubes for a pinch flat. Next winter hang the bicycle up or stand it upside down so it isn’t standing on the tires. The tires will still lose pressure but you can prevent tube damage.

Before you start pumping squeeze the sides of the tires together checking all around the circumference and look for cracks in the rubber. Pull out any sharp objects that may be stuck in the cracks. If the tire cracks are deep enough to show white at the bottom you are looking at the tire casing which is the inner cloth layer of the tire which gives the tire its shape, flexibility and strength. If you can see this casing you’d better replace your tire because it is worn out. It’s also worn if the sidewalls are deeply cracked or if the tire tread is worn down to the casing. If the tire isn’t worn in any of these ways then inflate it to the maximum pressure listed on the sidewall and ride.

Yet worn tires may be a good thing because you can replace them with better ones for your future rides. Many people were sold mountain bikes or fat-tired hybrids for commuting because those are the bikes people feel safer on at first. New riders often think that fat tires will be safer on the streets.

Another common misconception is that knobby tires are good for traction. Yes, they are good for traction, but only on dirt. Unless you ride through forests and fields on your way to work, you will be riding the streets on the equivalent of a tractor tire. This is causing you lots of extra effort. As a matter of fact your whole mountain bike was designed for off road riding. But don’t despair. You don’t need to switch bikes right away, just change those knobbies for something useful.

My wife’s hybrid bike had fat, 26” low knob tires and I replaced them with completely slick (smooth), high quality “Kojack” tires by Schwalbe. She was afraid that a completely slick tire would be unsafe but after just one day, she was sold. Her ride to work was faster with no extra effort. One reason is that slicks have a greater contact patch with the road.

Think about it.

A smooth tire touches the road with it’s whole surface, even if it’s only 2 square inches. A knobby tire only touches the road with the tops of the knobs on that same two inches. So the slick has better contact for traction and braking. The second reason to upgrade is that higher quality tires have a better casing (the cloth under the rubber) so they can take higher pressure. Higher pressure translates into more speed. The better tires are made with better rubber compounds, which give you increased traction when cornering and better braking too. If your safety in traffic depends on the little patches of rubber making contact with the road, why would you buy cheap tires?

If your bike was a hybrid with 700c wheels you can trade up to even narrower tires. If you had 700c tires with 32 to 35 centimeter widths, try a slick with a 25 cm width. You’ll be fairly flying down the road! Of course don’t forget to keep pumping up your new tires every week. All rubber leaks slowly. And high pressure means speed. You will also get fewer flats when your tires are hard.