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Posted

There is only one number to use that is your FTP, your 60min effort / weight.

 

If you are using your 20min effort to calculate your power to weight ratio you just doing the same as people who cheat their golf handicaps... might make you sound good in the pub, but doesn't mean you do well out on the course.

 

SNIP

 

 

 

It is a highly acceptable measure of one's threshold, Patch'.

Or maybe you were joking.  :huh:

A 60 min effort is not easy to produce as it requires finding that suitable course (where pedal force can be constant and effort level at a good grind). Locating that slight gradient is virtually impossible anywhere unless you stay a few clicks from the Tourmalet.

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Posted

It is a highly acceptable measure of one's threshold, Patch'.

Or maybe you were joking.  :huh:

A 60 min effort is not easy to produce as it requires finding that suitable course (where pedal force can be constant and effort level at a good grind). Locating that slight gradient is virtually impossible anywhere unless you stay a few clicks from the Tourmalet.

That is very true.

Posted (edited)

It is a highly acceptable measure of one's threshold, Patch'.

Or maybe you were joking.  :huh:

A 60 min effort is not easy to produce as it requires finding that suitable course (where pedal force can be constant and effort level at a good grind). Locating that slight gradient is virtually impossible anywhere unless you stay a few clicks from the Tourmalet.

Oh no, maybe you got me wrong.

 

I know the test is super accurate. (20min effort *0.95 = FTP) I do the same. There has been many many studies that show the near identical correlation between the two.

 

What I meant was use the FTP number to calculate your power to weight, not your 20min figure. Or at minimum be clear that its your 20min effort when quoting that figure.

 

Many of my friends have just started training with power, and they keep referring to their 20min test results as their FTP in our conversations.

Edited by Patchelicious
Posted (edited)

Oh no, maybe you got me wrong.

 

I know the test is super accurate. (20min effort *0.95 = FTP) I do the same. There has been many many studies that show the never near identical correlation between the two.

 

What I meant was use the FTP number to calculate your power to weight, not your 20min figure. Or at minimum be clear that its your 20min effort when quoting that figure.

 

Many of my friends have just started training with power, and they keep referring to their 20min test results as their FTP in our conversations.

Oraait

:thumbup:

FTP is 20mins avg watts minus 5%

FTP is 60 mins avg watts

 

THEN add your weight and divide and get the real relevant data at w/kg

Edited by ' Dale
Posted

Just a question regarding the 20min FTP.

 

 

Basically at the beginning of the ride its very hard to hold the wheels and I even get dropped, towards the middle holding the wheels become easier and toward the end of the ride I start riding away from the very same guys that killed me at the beginning.

 

So basically 20min FTP will be lower then all, but as the time goes on either get stronger or the others get weaker.

 

How does that fit into this 20Min FTP test?

 

 

Posted

They should be same....100kg dude is pushing out 400 watts and and skinny dude is pushing out 264...so they should be the same ..no..???

For equal FTP expressed as W/kg they should climb the same - BUT - on the flat, you will probably find that the greater absolute FTP will be faster - so on the flat the 400W guy will most likely take it.

Posted

For equal FTP expressed as W/kg they should climb the same - BUT - on the flat, you will probably find that the greater absolute FTP will be faster - so on the flat the 400W guy will most likely take it.

You need to overcome 4 types of resistance in powering a bicycle forward. Gravity, wind, road/tyre resistance and drivetrain friction. The relative importance of these at any time depends on factors such as gradient and speed. For example wind resistance increases with speed. The power required to overcome gravity increases with gradient.If two riders have the same W/kg the impact of gravity is neutralised so it becomes a question of the other forces relative to their absolute power. Wind resistance is by far the biggest of these. However wind resistance is also rider specific. It is possible that a lighter rider with a lower absolute wattage but better aero equipment and position could be faster even if their absolute wattage is lower or simply because their surface area ("cda") is smaller because the incur less wind resistance. However, v12 is correct that if the riders were also similar across these dimensions then the rider with the higher absolute wattage would be fastest.

 

One other minor technical point. If the weight of the bicycle is not included in the w/kg calculation, then technically when the weight of the bike is included the lighter riders revised w/kg will decrease by more than the heavier rider because the bike adds a bigger percentage of additional weight.

 

In short quite a difficult question to answer without the full specifics of each rider.

Posted

There is only one number to use that is your FTP, your 60min effort / weight.

 

If you are using your 20min effort to calculate your power to weight ratio you just doing the same as people who cheat their golf handicaps... might make you sound good in the pub, but doesn't mean you do well out on the course.

 

My last 20min Test was in Jan before the races started. I was 83kgs then and FTP (60min) was 281W. - 3.4W/Kg

 

I should be up as at the Walkerville I averaged 260w for 3 hours.

 

Been on a horrible "build phase" for last 2 weeks and an even worse 2 weeks starts next week (read many many minutes in VO2 Max as well as above that!!), so when Barry "the devil" Austin sends me to Bicycle Power in 3 weeks time for my next 20min hell hole, I hope to be around 5% - 7% up from there. I am down to 78kg and will hopefully be closer to 76kg by then. Nice thing about being a fatty is that losing weight is much easier than upping power, so you can get lekker PWR/W ratio gains just by not being a greedy little piggy.

 

If those two figures are achieved, it will mean a 4W/Kg FTP which is my goal for Jock.

 

Sucking your wheel at the jock :ph34r:  :whistling: 

 

Scary thing is its only 6 weeks away  :eek:

Posted (edited)

So this big guy was sitting on the Wattbike next to me in the gym and looking very impressive as he was pumping those "Rugby prop" legs. I peeked at his screen and did the same hart rate as him- then looked at his Watts/ KG only to see it was 1,7. Now Mr Skinny here next to him was doing 3,1 Watts/ Kg.

 

Now I know why "rugby props" play rugby and do not ride the TDF

Edited by Groenkloof1

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