Q. Do you have zones e.g 90% of Max power, 80% of power etc.
A. Yes there are 7 zones. These are based on your threshold power which can be measured without the need to go to a University with the PM at home. This article outlines the levels http://www.coachingireland.com/article/article_67.shtml
Q. Can I trust/check my power-tap output, is there a way to check it?
E.g. that 300Watt effort felt a lot harder than it should have, maybe I was doing 320? Is there a rough calculation for Power->Speed factoring in wind, i.e 300W no/little wind ~40k etc
A. There are formulae these can be accessed on www.analyticcyling.com but you would have to be a maths genius to work it out on the road. All the power meters do require various degrees of calibration but it is very simple. On the Power Tap you have to ensure that the torque is zero when not pedalling but I have never had to zero mine in over 2 years of use. 300w always feels hard ;-). You can also do a test on your meter with a known weight to ensure that the calibration is exactly correct http://www.midweekclub.com/powerFAQ.htm#Q23
Q. How much power should I be generating based on my weight, isn't there known formulas to work this out to give a power to weight ratio. i.e.
350watts at threshold (I wish!) divided by 75kg is 4.66 which rates me in a certain category e.g. full-time, part-time domestic A or B rider
A. There are lists based on the power files from different categories which you can compare yourself to. I am unsure as to whether this is of great benefit however it does pinpoint what type of rider you are. The categorisation is based on 4 durations 5s, 1m, 5m and 20 min. If when you do your test your profile slopes from top left to bottom right the likelihood is that you are a sprinter and could excel in sprints on the track. If it is the other way slopes upwards from left to right this may be the sign of a good TT rider. However, for most people the profile is usually horizontal which is typical of a road racer. You have mentioned a very important phrase “power to weight ratio” which is the main determinant of cycling ability. You can say that a rider with a PTWR at threshold of 6w/kg will be better than a guy of 4w/kg, you cant and wouldn’t say a rider with a HR threshold of 172 is better than one with a HR threshold of 162! For example I have a 5min PTWR of 10w/kg, Srdjan is 12w/kg and Tim Cass is 14.5w/kg therefore we can safely say that TIM is most likely the best rider for a 5 min period and probably overall. You cannot do this with HR. as my threshold is 172bpm, Tim Cass 190bpm and Srdjan is 155bpm.
Q. Related to above question, what are the typical race requirements, e.g. 40K < 1hr = X Avg Watts, typical park race, avg ras stage
A. I am preparing an analysis of a pro riders power file while winning a park race last Tuesday. This will give us an insight into the requirements. Off the top of my head his threshold from this file was 330ish and the weight is 60kg giving a PTWR of 5.5w/kg.
This is interesting http://www.pezcyclingnews.com/?pg=fullstory&id=4119 as it outlines the requirements to ride the tour.
Q. I'm only starting off racing, should I buy a HR or Power Tap?
A. Neither get a coach first.
Q. Finally I agree with Niall and Noel would need to factor in HR's and Gear recommendation when specifying drills based on power output.
A. No I think I have given enough information here for you to change that opinion. I hope so anyway
I like the measurement of power as it gives a reality check of how well your going (as does the speedo coupled with knowledge of the terrain) although HR is needed as well for a more comprehensive analysis.
At the end of the day all you can do is your best so HR might be enough to tell you how hard you are pushing it even though the power might not be as much as someone else with the same effort measured by their respective HR but your speedo (and road gradient info) can tell you this, no need for a Power Meter ?
Q. Srdjan mentioned that in the wind HR values can be deceptive and power values are better but I don't see why as power and HR should 'always' be directly proportional to each other hence the 'threshold HR' and 'threshold power'.
A. No unfortunately they aren’t directly proportional. When you start your year of training your HR threshold may only be 10bpm lower than when you raced the previous year but you power may be considerably lower. The Hr will return to normal value quite quickly and will remain at that level for the rest of the year. However, the power will be the only element that increases.
Q. Noel has exposed the limitations of a sole power measurement and I bet Anto can give tell us the limitations of a sole HR measurement.
A. I don’t think that this is true I hope now that you will see sole power measurement is really 99% better than HR.
Q. BUT with the SPEEDO AND HRM you can see the optimum Cadence so do I really need to splash out loads of money on a power tap that adds weight to by bike ?
A. NO you don’t have to part with the hard earned money. I think for the amateur the PM is more advantageous than for the pros. After all we have limited time to train the PM will allow you fine tune and make the most of that available time. Speed cant be really factored in here I cant see how I can judge training intensity using speed but at the end of the day it is the most important aspect of cycling…if you are the fastest you win!
Q. If your mental arithmetic is good enough you could always calculate your power from the cadence value and the prior knowledge of how much force you require to push certain gear ratios (this involves multiplying 3 numbers, the other being a constant i.e. [2phi x crank length]) !
A. If you can do it every second as the PM does well that’s good enough for me.
Q. I intend buying a heart rate monitor and combined speedo or maybe a 3 in one HR, Cadence and speedo - I heard Polar do this - How many sensors ? (one on spoke for distance [with time to get speed] and one on the crank, can this be reduced to just the one on the crank ?)
A. Don’t buy a HRM…I will give you one for nothing..
