Hot answers tagged

20

The most important thing is to make sure your core temperature is high enough. As your body begins to chill, it pulls blood away from the extremities, to maintain its core temp. Often times cyclists will think "my core temperature feels fine, but my hands are cold" so they think they need warmer gloves, when in reality they need another jacket/vest/jersey/...


18

TLDR; assuming my calculations below are correct, there's roughly a 10% increase in air resistance between hot, humid days, and cool, dry days. Add in a slight but imperceptible tailwind or headwind, and it's conceivable that you could experience a 4–5mph difference in cruising speed between two days. Air resistance is the primary force a cyclist must ...


13

If the effect of wind resistance was linear with respect to speed, then yes, the forces would balance out. That is to say: if pedaling into a 20 mph wind was only twice as hard as pedaling into a 10 mph wind, the forces would balance. But this is not the case, as @Daniel mentions. The effort to overcome the 20mph wind is more than twice that needed for the ...


12

The most accurate way to do it would be with a pitot tube to measure wind velocity and then to contrast that against speed-over-ground from your GPS or wheel speed sensors. Before one laughs about the science-fiction nature of this, there's a product that does so: The PowerPod (link is to DC RainMaker's review of it). The Isaac software that comes with the ...


11

Arguably, just the time it takes you to get from point A to point B is a perfectly good measurement of improvement (same with average speed) As you say, wind influences this, as does countless other factors - traffic lights, weather (wind, wet roads, snow and ice, etc..) However, unless you are remarkably lucky or remarkably unlucky, these variables will ...


11

You can do it, because your bike is connected to the ground. The work done when moving an object is proportional to distance and resistance force (which consists of air resistance and rolling resistance for bikes). The air resistance depends on air speed (ground speed + wind speed), but distance depends only on ground speed. Going slower reduces the energy ...


10

Look for gloves made with a Windstopper material. I have some pretty thin gloves made with this and stay warmer then my thicker gloves because they stop the wind so well. You may want to look at lighter weight running gloves made with this as I find them a little more pliable. Most I have seen are not waterproof though.


10

As you might expect, the exact down slope you would need for a full answer will depend on how much drag you and your bicycle produce. If you are very aerodynamically efficient and there are few losses through the bearings and tires, the slope can be shallower. If you create a lot of drag either via aerodynamic inefficiency or mechanical and rolling ...


9

They'll never provide as much insulation as ski gloves, on their own - they're not designed to. They're intended to block the wind (so minimising the convection heat loss due to high airflow) but still allow you to breathe (which implies you still get the heat loss due to evaporation). A wicking/insulating liner underneath will add some straight insulation ...


9

As you have guessed, it is better to work harder on the uphill and rest on the downhill. And as others have mentioned, whatever works for you on the uphill in terms of balancing high cadence and mashing is best. However, there are a few guidelines that you can follow to approach each situation in the most efficient manner possible. Downhill: Since wind ...


9

Anything colder than -55F (-48C) is difficult to mechanically maintain. Most lubrication products on the market for cold weather are rated to -60F (-51C). Which means that at -50F (-45C) they become almost unrideable and at -55F (-48C) pretty much unrideable. I am aware of products rated for colder than that, but they have issues that when stored at room ...


8

Basically whatever works. If you're trying to conserve energy it's foolish to push yourself going downhill, since energy lost per mile to wind resistance increases with the square of speed -- just take advantage of the "free ride" on a reasonably steep hill. Going uphill depends a lot on your physical condition and how steep the hill. You first need to ...


8

The Varna, which was one of the best bikes in 2003 has speed + power graphs up from their Battle Mountain runs that year. At 80kph Sam was putting out about 225 watts, but accellerating. There's also a 0.5° slope to consider. This article suggests that the bike uses about 150W at 50mph/80kph. Sam weighs about 80kg, the bike about 25kg. Let's call it 110kg ...


8

You can do this because of the gearing of the bike. When you're riding at a slower ground speed, if you shift to a lower gear to keep your pedal RPM the same, then the same force on the pedals produces a higher thrust at the tire. Even if you do not shift, it is easier to produce higher force on the pedals at lower RPM. The strength of a cyclist is ...


8

Having ridden near Bristol this morning in a similar forecast gust speed, I'd say you're right to be worried, but keeping aware of the wind direction and speed can make a huge difference. For example: passing side roads on your left, if the wind is coming from the left, you may want to aim slightly towards them so that you get blown back towards the middle ...


8

When you're in font of the rider that you want to help, then the more aero you are, the less shelter you give. Riding in a low body position, head tucked and arms narrow makes it easier to ride at speed, but means that you aren't puching through the wind as much for the rider behind you. You'll want to sit as upright as possible, arms a little flared ...


7

A tailwind reduces your relative airspeed and therefor the drag you generate. You can go faster relative to the ground with the same power output. The only time increasing your profile might be beneficial is if the wind is traveling faster than you are, relative to the ground .... Unless you cycle slowly or the wind is very fast, it's usually not the case. ...


7

We like tailwinds as the effort to ride at a given speed is lowered. In the same token we like slight downward slopes. If you base your riding on effort, rather than a fixed speed, you will automatically utilise a slight tailwind. If you however ride at a fixed speed, you simply had an effortless ride. In other words, you missed nothing.


6

You can get explicit cycling knee warmers - I have a pair of these which see a lot of use (and sometimes go under jeans, very comfortably, if I'm out of an evening too). They are great for the morning commutes where it is cold but likely to be warmer by the time of the return journey, but also for the longer rides where you start colder than you'll finish ...


6

Small changes in bike fit make dramatic differences in performance. Heat and humidity make a big difference.


6

In short no. You're actually better off measuring power, through a powertap, SRM or similar ergometer. This gives you a measure of your physical performance that is absolute. So your speed is a factor of your power output, chain efficiency, wind resistance, drag, tyre performance, road surface, atmospheric pressure, and gradient. It is almost impossible to ...


6

@Daniel has made several comments that capture what experienced cyclists have learned. You think something like I'm going well, or killing it, or even (as happened today) this looks like it's uphill, while blasting along. When you stop you discover the awful truth. It's a headwind home. The reality is that we nearly always have a headwind, especially as ...


5

I commute (cycle) for 60 minutes each way. I wear summer (thin and fingerless) cycling gloves in temperatures down to about 40F (5C). At 50F (10C) I'm wearing a short-sleeved shirt, and short pants, as well. I'm totally relying on the extra heat I generate (from exercise) to stay warm. You must adjust your clothing to match, not only the outside ...


5

On high humidity days, the air has less mass due to the more H2O, which is lighter than typical O2, CO2 and N2 weights. On high pressure days there is more mass for you to push aside. Air temperature also plays a part - hot air is less dense than cold air. Therefore a hot, low pressure, high humidity day requires less mass to be pushed aside. These make a ...


5

Probably you are looking for bar mitts (pogies). HOWEVER -- until recently I wanted to buy them, 4 months ago I had a nasty accident in comfortable conditions, just pure bad luck, that's all. From that point on I said "no" to any device that attaches me to the bicycle -- the reason is, in case of accident it is a split of the second, when you can fall on ...


5

I'm a commuter who has to carry things like books, a notebook, food for the day, bike lock, etc. I should say that it makes a striking difference whether you carry stuff on your back or on a bike rack -- a heavy bike is not as bad as a heavy backpack, in other words. Another thing that I've noticed is that my performance decreases if I ride five days a week ...


5

If you are biking along and you encounter a terrible smell -- look around and realize that it's you yourself that you're smelling -- then you're in a tailwind -- and that it's time you washed your bike jersey. Thank you for the downvotes, I'll show myself the door. :-)


5

Specific product recommendations are off topic on this site as they tend to become obsolete quickly. There are plenty of breathable windproof, cycling specific jackets available and reviews are easy to look up. Wearing a wind-permeable fleece on a bicycle in cold weather is less than optimum because cycling always involves wind (although you are moving ...


5

The answer to your questions is not straighforward, as shown below. The easiest to answer is your first question: are X and Y the same? No, they are not. This follows from the formula for the air-drag power Pa = ½.rho.Cd.V.(V-Vw)² , where rho is air density, Cd is drag coefficient, A is frontal area, V is forward speed, Vw is wind speed. Suppose that for a ...


4

The only thing that will work for everyone in all situations is to wear a heart rate monitor and ride right at your aerobic threshold. Otherwise, it will be mostly personal preference, for loose meanings of "shortest amount of time possible".


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