FYI HAC4 power measure vs Powertap

bahzob

Quick FYI if anyone has a HAC4. I did a quick test yesterday to see how it measured vs Powertap (so I can incorporate fixed rides into my training plan).

The HAC4 proved not to be too far off the mark on power measures when climbing but underestimated by about 40W on the flat. I guess similar may apply to other HRMs with indirect power measures but would need checking.

Details here http://mr-miff-on-tour.blogspot.com/

dennisn

Gotta be honest. That's just to much for me to deal with. What do you use all that info
for?

Dennis Noward

Alex_Simmons/RST

bahzob wrote:

Quick FYI if anyone has a HAC4. I did a quick test yesterday to see how it measured vs Powertap (so I can incorporate fixed rides into my training plan).

The HAC4 proved not to be too far off the mark on power measures when climbing but underestimated by about 40W on the flat. I guess similar may apply to other HRMs with indirect power measures but would need checking.

Details here http://mr-miff-on-tour.blogspot.com/

How about a fixed PT wheel? All you need is a cheap 2nd hand PT Pro and a fixer kit from wheelbuilder.com or surly.

I had a look at your performance manager chart. I must say, I have a hard time believing your CTL lifted 50 pts from 86 to 136 in less than 2 weeks during Raid Dolomite. It suggests to me that either your PM is giving you weird numbers (with a PT that's possible but unlikely) or that your Functional Threshold Power value is set way too low.

bahzob

Alex

Re PMC+Dolomite: Think this illustrates that training etc needs to take account of context. My rides are sportives/tours with TTs done just for training. So did a lot of training over winter to build to May but after June/July jjst maintained with little structured training. (The PMC is retrospective, I only started using it from October)

So Raid did represent step up in terms of volume (its an 11 day ride from Lake Geneva across the Alps/Dolomites averaging 125km/2200m climbing per day) so think CTL graph is OK. That said lesson I take is that I could train harder, using PMC as guide, and will do so this year.

Re: PT in fixed: May do this but not just yet. If I get another PT it will go in MTB first.

Dennish:

What use info for? Following on from above I had a sort of plan for last year but did not really follow it too well. This year plan to be a bit more structured. Will be using WKO as my main tool for this and want to be able to put in something from my fixed rides, so the CTL line Alex mentions is correct. Appreciate this approach is not for others but works for some.

cervelorider

The first thing that occurred to me was that a more precise comparison could be made by fitting the HAC4 onto your Giant, which is powertap enabled, and run the 2 systems side by side.

Re the retro-PMC, I hadn't considere to FTP being low, but it would make sense, as there seems to be very little in the way of taper before Raid, meaning the training load leading up to it was fairly low with regard to TSS.

bahzob

cervelorider wrote:

The first thing that occurred to me was that a more precise comparison could be made by fitting the HAC4 onto your Giant, which is powertap enabled, and run the 2 systems side by side.

V true and should have mentioned have done this previously with similar results.

Alex_Simmons/RST

bahzob wrote:

Alex

Re PMC+Dolomite: Think this illustrates that training etc needs to take account of context. My rides are sportives/tours with TTs done just for training. So did a lot of training over winter to build to May but after June/July jjst maintained with little structured training. (The PMC is retrospective, I only started using it from October)

So Raid did represent step up in terms of volume (its an 11 day ride from Lake Geneva across the Alps/Dolomites averaging 125km/2200m climbing per day) so think CTL graph is OK. That said lesson I take is that I could train harder, using PMC as guide, and will do so this year.

Re: PT in fixed: May do this but not just yet. If I get another PT it will go in MTB first.

Context isn't really relevant.

Just looking at the fact that on a base CTL of 56 TSS/day you rode 2 consecutive weeks of 2,400 TSS per week (~340 TSS/day)! Holy crap :shock: . It just looks suspect that's all, hence wondering if FTP was correctly set.

bahzob

FTP was set from actual 60min power on 25TT. So think its the best estimate but hope to improve this year.

Alex_Simmons/RST

bahzob wrote:

FTP was set from actual 60min power on 25TT. So think its the best estimate but hope to improve this year.

Well nothin' beats actual performance to predict performance. Nice work.

cervelorider

bahzob wrote:

FTP was set from actual 60min power on 25TT. So think its the best estimate but hope to improve this year.

I have read some comments on other forums with regard to how a higher FTP can be achived on a long(>60 mins) hill climb, as opposed to riding a 60 minute flattish(DC) TT.

I have yet to ride in the Alps/Pyrenees etc, so have no personal experience in these kind of climbs, but I have spoken to some top testers(using PM's), who have experienced ~10w increase in FTP on long climbs.

Alex, is this something you've come accross, and is there any general reason for it?

bahzob

Would be interested in reply to above myself. I have a lot of experience of riding in Alps/Pyrenees

I have not done an FTP test on a climb but I can imagine that restult may differ. One factor may be that on a psychological level the challenge of climbing a famous mountain climb can lead to a higher performance level.

What I can vouch for is how useful knowing your FTP is when doing these long climbs.

When touring I set a pace of FTP-40W or so which I find works for getting to the end of the day and ready for the next. For sportives FTP-20W is my target pace for climbs.

Alex_Simmons/RST

cervelorider wrote:

I have read some comments on other forums with regard to how a higher FTP can be achived on a long(>60 mins) hill climb, as opposed to riding a 60 minute flattish(DC) TT.

I have yet to ride in the Alps/Pyrenees etc, so have no personal experience in these kind of climbs, but I have spoken to some top testers(using PM's), who have experienced ~10w increase in FTP on long climbs.

Alex, is this something you've come accross, and is there any general reason for it?

Yes. It is common for riders to be able to produce higher sustainable powers at lower rider/bike inertia (such as riding up an incline or into the wind). Conversly it is common for riders to not be able to produce the same wattage when inertia rises (such as riding down a hill or with a strong wind at their back).

Maintaining similar hill climbing power on the flat or declines requires tremendous concentration - a small reduction in effort to the pedals doesn't have much impact on speed when on the flat with the wind or going down but when riding into the wind or up hill, the feedback is instantaneous and a rider tends to respond immediately.

cervelorider

bahzob wrote:

Would be interested in reply to above myself. I have a lot of experience of riding in Alps/Pyrenees

I have not done an FTP test on a climb but I can imagine that restult may differ. One factor may be that on a psychological level the challenge of climbing a famous mountain climb can lead to a higher performance level.

What I can vouch for is how useful knowing your FTP is when doing these long climbs.

When touring I set a pace of FTP-40W or so which I find works for getting to the end of the day and ready for the next. For sportives FTP-20W is my target pace for climbs.

I would expect two outputs: one for a climb done in the middle of a ride that combined several long climbs, and one which is done as a single mountain time trial, with just a warm-up prior to the start, as this alone would create a contrast.
I am considering that the power increase that I initially wondered about, are due in the main to the resistance that would prevail throughout the entire 60 minutes. This is in contrast to the slight undulations, and also the drags and slight downhill sections encountered in a UK style 60 minute TT.

Given the paces you mention for touring, how long are the total ride times, and how many long climbs are included per ride?

bahzob

cervelorider wrote:

Given the paces you mention for touring, how long are the total ride times, and how many long climbs are included per ride?

The two main rides I did 2007 were Pyreneen and Dolomite raid + some extra rides before after. Averaged 160km/day on Pyreneen, 130km/day on Dolomites, ride times varied from 4 to 9 hours. Number of cols varied from 1 to 8 (last was bit of extreme day going for 5000m+ climbing)