The tag has no wiki summary.

learn more… | top users | synonyms

3
votes
3answers
108 views

Shifting can't keep up with my acceleration

I noticed that when I really give it hell after stopping or riding slow (I do that all the time on commute), I have to shift two gears at a time in the lower gears, to keep up with my acceleration. I ...
3
votes
4answers
177 views

Solar charger for iPhone whilst on a bike tour - is it worth it? [closed]

Are there any feasible solar chargers for iPhone / or with a usb slot that will work or is a backup battery available. Best value (and something that works) is my priority. I found this brilliant link ...
2
votes
1answer
47 views

Proper Weight input for a indoor power meter

When setting up the power meter on an indoor Elite Digital Mag Trainer should I put in my weight plus the weight of my bike when I input the weight?
1
vote
1answer
156 views

Allen Coggan Table - Formula for a best fit to time frames

I'm sure lots of people are familiar with the Allen Coggan Relative Power table that then relates your 'score' to what category rider you are. My question is that given rides/segments/hill climbs are ...
2
votes
4answers
515 views

What's best engine to motorize a road bike

I have a road bike I use for commuting and I'm about to move 20km further out, so I'm considering fitting a tiny engine to it to assist my ride to work. However, where I live I have a restriction - ...
2
votes
2answers
579 views

How can i calculate the power in watts on an indoor trainer

I am trying to calculate the power needed to hold a steady speed on an indoor trainer, so as I can train using power in watts. I set the bike up and put the crank at 90 degrees, then put a weight of ...
2
votes
2answers
2k views

How accurate are indoor trainer power meters?

I recently got a Tacx Flow trainer, this being the first time using a power meter. For about 10 years, however, I have been doing monthly "uphill time trials," whereby I put the time into that formula ...
11
votes
4answers
1k views

Extra power needed uphill for weight increase

How much does weight mean when going uphill? Let's say I'm going up a mountain with 1000 m of elevation and it's quite steep: 10%. Let's also say I can maintain 250 watts. If I add 1 kg of weight to ...
4
votes
2answers
757 views

What is preferred lacing for PowerTap wheel build?

I've done quite a few wheel rebuilds to make them stronger, but haven't built up a wheel around a PowerTap (SL+) yet. This will be for a training set for a fit triathlete. Raw weight is not an issue, ...
7
votes
3answers
829 views

How can one estimate drag for a bicycle?

I am curious how to estimate drag for a bicycle. This has two different framings: Find the amount of power required to ride at a certain speed. That is, when one is traveling at a constant speed, ...
4
votes
2answers
4k views

How accurate are the power numbers from a Tacx Flow?

How accurate are the power numbers (watts) from a Tacx Flow? Multiple aspects : Absolute number : can they be compared with numbers from other power meters ? Relative : if ride two times at 200 W for ...
4
votes
4answers
7k views

How do I calculate the power required to climb a hill at a given cadence?

Suppose I ride at a cadence of 50RPM for 10 minutes with a 39x23 gear ratio on a hill with 10% grade. Is there a simple formula to calculate the power output required?
15
votes
3answers
7k views

How do bicycle power meters work?

What exactly are they measuring? How do they measure it? What are the implications of the different approaches on accuracy / speed of getting a good measure? It would be helpful if someone could ...
7
votes
5answers
2k views

Does gear ratio affect Power?

Let me preface by saying that this may not be the right SE. I considered asking on the Physics SE, but I thought I might try here first. If it is wrong, I am not against it being migrated. From basic ...
11
votes
5answers
791 views

What's the cheapest way to get into training with power?

I used to train with a stopwatch, and later on, heart-rate. Both required relatively inexpensive tools. Now I'm interested in training with power (measuring the watts produced) and I'm finding that ...
7
votes
5answers
1k views

What are the 'easiest' ways to determine functional threshold power?

I recently picked up a powertap and have done a fair bit of riding around and a few races now with it on, so I've started to get familiar with some of the numbers. I would like to figure out what my ...