Leg power discrepency

swampy1970

First one. Do the Ergomo's read a different value than comparable units (SRM, PowerTap) consistantly or does the reading 'drift' somewhat under a proven steady power - ie, if I were to hook up a 1/2 hp electric motor to the bottom bracket of an ergomo device would I see a constant ~373watts or a constant 350watts or a range that fluctuates between say 360watts and 386watts for that given measured load? Just curious as I'm going to be in the market for a non-SRM power measuring device - unless Frank wants to swap my PowerCranks for one of the new SRM equiped PowerCranks for a nonimal upgrade fee

(that's the only way the set of Powercranks that's currently on my bike will be removed.)

Secondly. I've kept the training pretty constant over the last year with the exception of two things. One, I had a lengthy period of time off the bike in October and early November - during this time off, all of which was on strong pain meds I put on the extra weight. When I got back on the bike I noticed on regular cranks that I was obviously slower on the trainer. Two, I changed from regular cranks to powercranks towards the end of November. The training load was somewhat reduced during the initial adaptation period and instead of being a 30 minutes on, 5 off, 25 on, 5 off, 25 on..... it was similar time periods that were fragmented, eg 30 minutes on but split into 10 sub intervals where a rest was required due to the inability to pedal any more and initially I was limited to the initial 30 minute session. Over time these "sub intervals" were reduced in number until the desired 30 minutes, 25 and 25 were achieveable. My training is done on the trainer this time of year as I only have late evenings in which to train which is why I don't get a nice 3 hour ride in....

I have to say that my pedaling has changed. I no longer have to think about pulling up - it happens because it has too and yes it still hurts but I now think more about pushing down earlier and harder. Maybe it's due to the lack of thought required but it does actually feel more natural. It's been noted that cadence is a problem when getting used to the Powercranks, but I'm hovering around the 80rpm range most of the time now and that's rising by an a couple of rpm per week at the moment.

As stated in a post in another thread, I'm not sure why I was faster on the hill I use for testing - was it time that I made up on the steeper sections or on the flatter parts. I used that hill all the time for climbing training as it offers a nice mix of 6% and 18% for the first 3.5 miles.

I'm also seeing higher average speeds and slightly lower heart rates on the trainer too. Every week a check tire pressure and restistance (coast down time for backwheel from 20mph) for consistancy.

giannip

why do the PC users not use them for racing ? weight ?

Apologies but it's the first tme I've heard of them

Fday

Lot's of reasons. First, they would be illegal for some racing, track most notably. Mostly, I think, because they don't feel up to speed on them enough and their mind set is "regular cranks are better for racing because of the weight factor". Weight is probably the main excuse people use, I think. Another reason that some may not race on them is to not alert their competition to them. The longer their competition is in the dark about them the bigger advantage they will have. Anyhow, I suspect there are as many reasons are there are people. Maybe some of them will speak up as it is clear there are some here.

Fday

Sorry, I missed answering this.

There are two secrets to getting out of the saddle on PowerCranks. You have to understand the different coordination and you have to understand how to control the pedal speed when you come out of the saddle.

To understand the different coordination come out of the saddle and pedal one legged. Pay attention to how you are using your hamstrings more in getting the pedals up.

There are two ways of keeping the pedal speed under control. Use bigger gears and putting a lot of body weight on the handle bars. Every lb on the handlebar is one pound off the pedal.

Once you have done it once then you will be able to do it again and again and soon, without thinking about it.

swampy1970

Thanks! I'll give it a go.

LarsEjaas

Just wanted to shear my experience with powercranks. After training a lot on the cranks the past 16 months (around 17.000 km. total) I have decided to train AND race on regular cranks this season. I have made a "base" on powercranks during the fall and early winter, and then uninstalled the PC´s in the end of January. I still feel like I am riding the "Powercranks" way, and when I freewheel I still get the "kick" when the second pedal goes to the top of the stroke by itself unexpected :-)

I, of course have no way of telling if I am already slowly reverting back to "regular" pedaling, but at least it doesn't feel that way - and I am really happy with the changes PC's have made for me.

My plan in the next years will probably be to go almost exclusive PC's during the early off-season (trying to ride around 5000 km. on the cranks) and then do all of my training on regular cranks in the racing season. I know Frank thinks that the PC's are used best when training almost exclusively on them - but this just doesn't work for me.

The longest I have been off the powercranks is around 4 weeks in a row and after that I started riding on the Powercranks like I rode them yesterday - I'm not sure the ability is disappearing that fast, as long as the base on the Powercranks is large enough (and the initial adaption-phase is finished).

Fday

I think someone like yourself, who has a pretty substantial base, will revert back very slowly as long as you stay within your PC capabilities. By staying within your PC capabilities I mean, if the highest cadence you can maintain for any length of time is 85 but you get on regular cranks and try to time-trial at a cadence of 95 I think you will find yourself back to the old ways probably before that race is over, simply because you haven't trained that capability yet. Regular cranks seem so "easy" after PC's that it is easy for people to make "stupid" mistakes that hurt their performance during races, when the adrenalin is pumping, that they may not see in training.

The issue I have with training on regular cranks for someone like yourself is I think you will stop the potential for any further PC improvement that might occur during the season. If there is no difference to you between riding PC's and regular cranks I just don't see why you would want to risk any sliding backwards or forego any further potential PC improvement between now and the end of the season. I can understand occasionally training on regular cranks and I can understand racing on regular cranks, but I don't understand the racing rational of giving up the PC's entirely during the season if one is adequately adapted.

Steve_B

Frank,

Is it also correct to say that you also have no power meter data showing that someone puts out more power while using Power Cranks (assuming the adjustment period has completed)?

Fday

No, we have tons of power data that show very large power increases. My "lack of data" only goes to what happens when people stop using them. Most of our power data is anecdotal although there have been a few independent studies showing same, the most notable one being Dixon, who showed increases in both power (11%) and VO2max (15%) in only 6 weeks.

Today got an email from a customer who reports "I have been using the power cranks since November. I have noticed a 20% increase in wattage over a 30' time trial test with really no hard training such as intervals".

Reports like this are received routinely by us.

Billsworld

Fday, I have them and use them indoors for a specific purpose and mix them with roller work and weights. My only negative observation/suggestion would be to make a version that the pedals lock into the correct forward position. It is hard to get back into correct position when your hip flexors are on fire. Being a fast twitch guy , I simply dont ride enough to fully adapt. FWIW , I can sprint on them but tempo is brutal.

Fday

We do make a version you can lock into regular cranks, but you have to get off the bike to do it (takes about 30-60 seconds).

Billsworld

I still want the cranks to function in a way that requires contstant pressure in the full circle.(independent) I just want them to stop in the 180 position. Nothing worse than trying to find 180 position when your hip flexors are junk. Maybe I am a lazy trackie

Fday

I am working on something like that. Would be track legal and similar to regular cranks but give you feedback if you didn't keep 180º. Would have the most usefulness for those who are already PC trained so don't stop doing what you are doing. No time-frame yet but I am working on it.

Billsworld

Do I get to test the prototype?