Hot answers tagged

25

Since you say you're looking to become a triathlete soon it's far too early to be thinking of advanced training aids like power meters. The first few things to do (not necessarily in this order) are join a tri club enter a triathlon or two join a tri training squad observe your (comparative) strengths and weaknesses get a well recommended triathlon book. ...


16

If the pole is a flexible one, you can do the following: Choose a windless day Ride past a second person at a known speed Let the second person take a picture while you pass Repeat immediately in the opposite direction to capture the effect of the remaining wind. With the bike still, pull the flag back, measuring the force somehow. You can use a spring ...


14

Very quick answer - the torque numbers that are quoted are maximum torque values which do not correspond to maximum power. Power = torque × rotational speed, so, at slow speeds the motor unit can provide more torque (and hence more acceleration) while staying within the power limit. A bit more: There a decent page here on the characteristics of DC motors. ...


12

Presuming you are doing a standing start and coming to a complete stop at the top of the hill. The simple requirement is you need energy to move your from the bottom to the top. Most of the energy required will be to raise potential energy of the payload (you and the bike). Essentially you will be creating kinetic energy (moving the bike) by converting ...


12

The raw pedal force or torque data are difficult to work with but you can extract some information from them. First, note that Stages mounts the strain gages (or gauges) permanently to the crank, so the crank length is constant and they know what it is; that means that there is a one-to-one relationship between the kgf and torque columns. In this case, it ...


11

You can tell when you are knackered. Power indicates your actual output. With a baseline of previous power and HR data, you can establish a model for what you should be able to do. When your numbers start to fall way outside your model/baseline (you normally produce 250W at 80% of your max heartrate, but now you are only producing 200W at 85% or 90% of ...


11

There is only one occasion I would consider use of HRM has priority over a power meter (or indeed no monitor at all and simply using perceived exertion), i.e. your doctor or cardiologist has specifically requested you not exceed a certain HR. Otherwise there is no time that, if you have a power meter available, using an HRM trumps using a power meter. One ...


10

With that many interruptions your own performance is unlikely to make much difference to your commute times. Sprinting for the lights, when safe, is much more likely to help. If it's mostly stop signs rather than lights, getting going fast might help but you don't need a power meter to tell you that. For me, leaving a few minutes later in the morning makes ...


9

Aside from pacing better, if your cadence drops to 40rpm for too long and you are in your lowest gear at maximal effort for the expected duration, then you could probably use at least a gear 2/3rds or less than you currently have so you are likely to be able to sustain closer to 60rpm. That's possibly not feasible on your bike, but perhaps a 29 rear cog at ...


9

The physics model of cycling power and speed has been validated in the real world. Two examples are this and this. The model embedded in Analyticcyling.com's online calculator is based on these two papers. Whether the amount of difference calculated by the validated models is worth it to Joe and Billy is a question that can't be answered by the physics.


9

Can't I just measure my speed and compare it against my last run and see if I've done better? Yes, but it's only directly comparable if the wind (and surface, and traffic ... but particularly wind) conditions are identical. Since you don't usually have an accurate measure of the wind vector relative to your movement at each point on your ride, you're going ...


8

Mountain bikers regularly run these low cadences for very short periods, often at much higher power output. The issue with causing damage to knees is more about the duration of the climb and how strong your stabiliser muscles are. (Too much time mushing causes chronic overuse problems, while weak stabiliser muscles can allow injury to happen), however they ...


8

They do help with training and racing but they are also very expensive. As you say you are a beginner I imagine increases in fitness/strength (and therefore speed) are going to come fast anyway, even without a power readout to base training around. I would definitely invest in a HRM though and make sure the bike computer you use has cadence as well as speed....


8

The following chart can be found in an interesting article on Training Peaks blog. From this you should be able to adjust your power level occordingly.


8

Just coming back to this question as there are a few considerations. The OP only mentioned (barometric) air pressure and not necessarily altitude. I'll start with barometric pressure only and come back to impact of altitude. Typical barometric pressure variations at the same altitude, and hence impact on the partial pressure of oxygen (O2), are not so big ...


8

I did a ride of this length solo in March this year. I designed a route to suit me (not flat, not steep), and intended to be quick (I was aiming for under 21 hours). At 400km it was a tough day, but I never doubted I'd finish. I have seen people (tougher then me) go from a solid base of centuries/200km rides to this distance without anything in between, so ...


8

There may be some confusion with terminology here. A power meter measures power, usually by measuring the strain in some drivetrain component (i.e. how much it flexes when pedaling). You need to physically attach strain gauges to the component. This is usually a crankarm or pedal spindle, but strain gauges have also been mounted to bottom bracket spindles or ...


7

I will presume you are asking about the types of trainers that one mounts one's own bike onto, and not a dedicated "bike" trainer such as a Monark ergometer or a CycleOps Indoor Cycle (ergometers such as these are used in exercise physiology laboratories and can be calibrated to be very accurate). Consistency and Accuracy of Speed Measurement Accurate ...


7

Understand that the concern is not generally things like a muscle or tendon tear that can occur with, eg, extreme weightlifting -- off-road bikers might be susceptible to that sort of injury, but not a road biker. Rather, the concern is the injury that may be done to joint surfaces and structures due to repeated force, above some "tolerable" level, applied ...


7

We cannot know exactly unless Dowsett's team releases it, but we can make a reasonable estimate. The most important unknown is Dowsett's drag area, or CdA, so below I have calculated the power needed to average 52.937 km/h for various values of CdA, given the assumptions noted on the figure. Notably, rho is air density in the velodrome and a trackside ...


7

On flat terrain raw power is what is more important than Power to weight ratio. On rolling terrain P/W is important, but the larger rider still has the advantage. On mountainous terrain P/W is the determining factor. You can see this from races in pro cycling. Flat races are won by large strong riders and sprinters. Rolling races are won by mid size riders ...


7

Generally, you attach a bike computer or a power meter to a bicycle to collect statistics, and/or some sensors to yourself. A bike computer measures the revolutions per minute of a wheel, typically by attaching a magnet to a spoke of the wheel and using a detector attached to the frame which tells the computer every time the magnet passes the detector (so ...


7

A heart rate monitor (HRM) measures cardiovascular system effort, while power measures muscular system effort. When averaged over long periods of time the two are typically highly correlated, they can also diverge depending on the circumstances, for example in a sprint your HR will lag behind your effort or your HR for a given power effort can vary by ...


7

64 watts is well within the margin of error of 60w target. Don't be afraid of going to your lowest gear on the trainer. You should be working up to your target cadence, if you can't hold 90 without bouncing then you should aim for something lower. It will take time to get up there. 60w is relatively low for most people, it may become easier for you to ...


7

A 'bike computer' is a generic term for everything from a simple wheel sensor giving distance and speed, to an all singing all dancing computer that measure cadence, speed, altitude, heart rate, power and anything else you can think of A power meter measures the power you are outputting, and is one input into a bike computer. Power meters are expensive - ...


7

No. The Veloce crankset (assuming it's a 2011+ version) uses Campy's Power Torque system to attach the left crank arm. The Centaur crankarm offered by Stages uses Campy's Ultra Torque design, as do all of the Campy crankarms Stages offers. They are completely different.


7

Perceived effort isn't determined only by power output. That is, power output is certainly one of the things that affects perceived effort but there are others. There are (at least) two other possibilities: First, you may be overheating during indoor riding, so the perceived exertion is high compared to riding outdoors. In that case, a large fan can help ...


6

There are some bike hubs containing an electrical motor inside. If you google "bike hub motor" and take a look at the images, you'll get the idea. I think these ones are ideal since they require minimal changes to the overall bike structure, allowing for normal riding if the motor is not working, and they don't burn evil oil: you just plug the bike to the ...


6

The short and most direct answer to your question is to use your power meter to pace your ride optimally and Alex Simmons, who has given another answer to your question, was too modest to mention that he is an expert in this and has developed one of the most sophisticated power pacing models for variable conditions. A longer answer is, to paraphrase Prof. ...


6

From what I've read, adding a power meter betters measuring HR only, for some reasons: Heat, diet and stress can affect your HR. A low HR might be an indicator that you are in good shape. You can have a high HR and your power output be low An increase in power implies better performance, but an increase in HR does not necessarily. So it is good to combine ...


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