Power to weight ratio

Raymzor

http://www.bicycling.com/training-nutrition/training-fitness/trainingpeaks-power-profiles-cyclists

Thought this was worth posting!!! my 5 minute ratio using the strava calculation is 4.0!

Cookie_Monster

4.55 if I correctly remember what weight I was on the W200 last year

Beasty

The Strava estimate is pretty meaningless - you need to adjust for wind speed/direction, aero position/gear, whether any drafting benefit is obtained and lots more. I think the only things they take into account are terrain, speed and possibly weight

Cookie_Monster

Beasty wrote: »

The Strava estimate is pretty meaningless

it's just one more statistic you can use to beat imaginary internet people over the head with

Lumen

In addition to Strava power being very inaccurate, those tables don't map very well to Irish racing categories.

e.g. table shows mid-level cat 4 of 4W/kg for 5 mins, which would be about 270W for me. You would get dropped at the first sniff of a hill in an A4 race with that power output.

Raymzor

Lumen you are right. i even get dropped in club races with the slightest lift in the road!

harringtonp

Lumen wrote: »

In addition to Strava power being very inaccurate, those tables don't map very well to Irish racing categories.

e.g. table shows mid-level cat 4 of 4W/kg for 5 mins, which would be about 270W for me. You would get dropped at the first sniff of a hill in an A4 race with that power output.

I would have suspected the tables are fairly accurate. Did a 8 min field test (maximal effort) on a gym bike recently and came out at 334W average. At 81KG that is 4.12 Watts/KG. On that table that puts me towards but not at the upper end of A4.

Only one of the the A4 races I did this year had a decent (longish) hill on it. The pack split to pieces (only race where it did) and I found myself in a group of 6 over the top chasing a group of 8 with 2 further groups of about 15 behind.

Limited data of course (and wattage on gym bikes could be way off) but it would seem about right.

NeedMoreGears

Beasty wrote: »

The Strava estimate is pretty meaningless ...

That's good news as I was well under the four mark.

On the downside it probably means my best ever VAM of 4600m/hr was a tad inaccurate as well.

ROK ON

Beasty wrote: »

The Strava estimate is pretty meaningless - you need to adjust for wind speed/direction, aero position/gear, whether any drafting benefit is obtained and lots more. I think the only things they take into account are terrain, speed and possibly weight

If you use it on a turbo?

Some statistics may not be accurate - that does not mean that they are totally without use.
Any statistic that has a stable flaw in calculation, can still provide useful information - it simply cant measure what it is supposed to.

A user of this statistic can still measure progress (or lack thereof) over time.
In the case of power on a turbo calculated by strava - for some people it may not be as relevant if the power is under/over estimated - as long as the error entirely consistent. From what I understand the power function on STrava is inferred from HR, weight speed etc. I am not questioning its validity at all - however if it is consistently wrong, surely I can still use this to measure improvement over time.
It simply wont be improvement of an accurate power output, but it may indicate some improvement in power.

I don't really care what my power is per se (because it is stupidly embarrassing no doubt).
However over the course of a few months I do want to gauge improvement.

Lumen

harringtonp wrote: »

I would have suspected the tables are fairly accurate. Did a 8 min field test (maximal effort) on a gym bike recently and came out at 334W average. At 81KG that is 4.12 Watts/KG. On that table that puts me towards but not at the upper end of A4.

Only one of the the A4 races I did this year had a decent (longish) hill on it. The pack split to pieces (only race where it did) and I found myself in a group of 6 over the top chasing a group of 8 with 2 further groups of about 15 behind.

Limited data of course (and wattage on gym bikes could be way off) but it would seem about right.

Well, there are easy races and hard races.

In the A4 Stamullen GP race this year I was going backwards up Snowtown on the first two laps, during which I recorded 5 min intervals of 341W and 330W, which is 5W/kg and 4.85W/kg respectively.

The chart puts those power outputs between cat 2 and cat 3.

The chart also relates to maximal efforts, after which you have to recover completely. It is quite rare to record these in a race for obvious reasons.

My point is that these charts are pretty irrelevant in the grand scheme of road racing - I certainly wouldn't use them as any predictor of success. You have to beat whoever turns up on the day!

Morrisseeee

cha ching ching ching and that post count puts Lumen at..............

On topic: in terms of VAM, Lumen, what were the numbers ? (out of curiosity)

The 2 big-ish climbs I did this year (in races) required 1200-1400 VAM to compete at the top level of an A4 race.
I'm currently a fan of VAM especially on medium length (6%+) climbs, ie. I can then judge what I need to achieve or aspire to!

Lumen

Morrisseeee wrote: »

...in terms of VAM, Lumen, what were the numbers ? (out of curiosity)

The 2 big-ish climbs I did this year (in races) required 1200-1400 VAM to compete at the top level of an A4 race.
I'm currently a fan of VAM especially on medium length (6%+) climbs, ie. I can then judge what I need to achieve or aspire to!

I think those intervals included the the Snowtown Strava segment (1.6km@5.6%), for which my numbers were:

355W, 1283 VAM, 4:08
341W, 1252 VAM, 4:14

(I was dropped at the top of that second one)

Both times were slower than the women - the QOM was recorded that day at 3:57 :pac:

The KOM is 3:28. Sherlock's time from 2010 was 3:29 (1522 VAM), with a recorded wattage of 423W.

It's a short enough hill, but from what I recall there a bit of a bump before that segment during which people are pushing to stay up.

ryan_sherlock

I was about to comment on that one

RE: power data on Strava is very inconsistent so difficult to track progress. Having a well sheltered, smooth surface, constant gradient climb is what you need to track.

Cruagh bridge to bridge is is my one for Vo2max level efforts both training and test. Rode it full out the day after the champs (raspy breath, can't feel my arms type effort). Here: http://app.strava.com/rides/24253876#433808553

Broke my PR by a chunk. Almost 7.4 W/kg - Vo2max (5min) is around 7.1W/Kg. That type of climb/duration, is what I'm best at (more than longer climbs) if you use the power profile chart. VAM, 2040.

In Irish racing, you have to be able to made some very very big efforts, especially when the course is bumpy - most folks know this. For me, better to attack directly after the climb - everyone is fooked and no one wants to chase.

I remember the KOM effort from Stramullen that Lumen mentions. Hit the base, I rode hard, then Paul Griffin rode hard (I followed), then Adam Armstrong made a big jump - Paul and I were the only that could follow (tingling fingers type of thing) - only the 3 of us were off the front (didn't stick).

(oh, and I have a Cat 4 sprint)

manwithaplan

Lumen wrote: »

In the A4 Stamullen GP race this year I was going backwards up Snowtown on the first two laps, during which I recorded 5 min intervals of 341W and 330W, which is 5W/kg and 4.85W/kg respectively.

Sorry about that

(Edit - it didn't stick either)

Hmmzis

Lumen wrote: »

I think those intervals included the the Snowtown Strava segment (1.6km@5.6%), for which my numbers were:

355W, 1283 VAM, 4:08
341W, 1252 VAM, 4:14

(I was dropped at the top of that second one)

Both times were slower than the women - the QOM was recorded that day at 3:57 :pac:

The KOM is 3:28. Sherlock's time from 2010 was 3:29 (1522 VAM), with a recorded wattage of 423W.

It's a short enough hill, but from what I recall there a bit of a bump before that segment during which people are pushing to stay up.

Holy ****, that's some beginners level that A4 we have here.

I need to go and meditate on rule number 5 a bit.

Plastik

My 'strava' power for Snowtown in the A4 Stamullen GP that day were

351w, 1288 VAM, 4:07
348w, 1257 VAM, 4:13

And like Lumen, I went out the back. Chased like a dog to try and get back on, in a very disorganised/disjointed group, and never made it. That was my only time being dropped in an A4 race so far.

Idunnowho

The Strava estimate of power may not always be accurate given wind conditions, road surface etc but its not far off on a like for like basis... Ryan's powermetre gave 423W (3:29) for Snowtown, Strava calculated me at 414W (3:28) and I'm a similar weight (I was 73kg on the day... not coz I remember or log it or anything just because it doesn't move from that number). Ive seen other proximities in wattage calcs too given similar enough times so I reckon its a reasonable enough proxy albeit on an after the fact basis. Cant exactly use it for training but about a grand cheaper to give you some numbers afterwards.

rigal

Strava not at all accurate in my experience. Did a 1km climb on Thursday night with a powermeter at 364w and then did it 22 seconds faster today, no powermeter, at 287w according to strava.

Beasty

I have examples of Strava segments where I have done them in exactly the same time with actual Wattage being up to 50% different (one day around 200w, another around 300w). I would have expected the Strava estimate to be the same for each ride. Admittedly HR may have an impact though

A flat course with strong winds can give extreme results like this. Hills are generally a bit more consistent (as there tends to be more shelter and fewer drafting opportunities).