power meters that measure each leg output

slogfester · Post by **slogfester** » 16 Feb 2016 02:28

After 12 months of chronic sciatica, 2 back ops and 4 weeks of being house and bed bound, I am beginning to dream...

My left leg has undoubtedly got weaker. I was always right legged and things -I'm guessing- have got much worse recently. So when I rebuild my road bike (currently in bits in a box) I think it might be useful to have a power meter that enables me to focus on getting some balance back in my pedal stroke.

I've never even had a power meter before, let alone one that enables individual leg output, so would welcome comments and advice on what to read and purchase. (Some retail therapy is way overdue

).

Right up front.... should I bother? Should I get measured before I go splurge, to check if I really do have a in-balance? What is a 'normal' in-balance?

Thanks and greetings from 38oC Brisbane

Tim · Post by **Tim** » 16 Feb 2016 08:03

What would you do with the data? Probably the same as you should be doing whatever, whether you got one or not or if you did whether there was an imbalance or not: good rehabilitation and strength and conditioning forever.

But a gadget is always worth getting and cycling related gadget definitely worth getting.

Probably better spending it on a top physio or strength and conditioning assessment and training sessions including a Wattbike assessment (which would give you the leg discrepancy data). £500 on sports massage might do more for your performance http://www.qasport.qld.gov.au/services/ ... icine.html

Or really...both

laurence_cooley · Post by **laurence_cooley** » 16 Feb 2016 08:05

I'd suggest starting by reading this guide to pretty much every power meter on the market. From what I've read, there's not really agreement yet on whether it is actually meaningful to know left-right power balance (see, for example, this), although obviously you have a particular medical reason to monitor it.

An alternative would just be to find somewhere or someone with a Wattbike you could use every now and then. Either way, I hope your recovery goes well.

Andy Terry · Post by **Andy Terry** » 16 Feb 2016 10:27

+1 for Wattbike assessment (static, repeatable, controlled) plus targeted strengthening exercises prescribed by a professional.

dweben · Post by **dweben** » 16 Feb 2016 18:01

Bummer dude, know the feeling after years of continuously herniated discs.

Ease back into it nice and slow though, find the position that you're comfortable with which might be at odds with the norm. I.e I run about 10 deg nose down on my saddle and have a spacer under my left cleat... made from a tissue box! Works for my Igor style body though

Guess you know all the physio stretching/hydration advice. Stick with it, it helps. Might take some time, took me a couple years to nail the combo of triggers which does me over.

jdtate101 · Post by **jdtate101** » 16 Feb 2016 18:06

As for power meters the ones that Spring to mind being double sided are:

Pioneer
Cycleops Pedals
Garmin Vectors
4iiii
Brim Brothers
BePro
Stages???? (rumour there is a dual sided version on the way...SKY have been seen testing it)
Infocrank

Checkout dcrainmaker.com for reviews and prices etc....

slogfester · Post by **slogfester** » 17 Feb 2016 06:57

Thanks for the helpful replies.

Tim, I went to see my (long term) musculoskeletal physio today 2 weeks post op, for the first of many post-op sessions. I'm in good hands. She did her (2nd) masters on post op exercise routines for LBP. Some manual tests by her indicated that I had unsurprisingly suffered significant atrophy in the L leg and foot. At this stage it is too early to mechanically test it as I am still very sore. Apparently it could be as high as 30%, which is scary.
So I'll see if I can find a wattbike nearby for regular testing starting in a few weeks time.

In the meantime and in addition, I'll take a look at the power meter refs suggested. If these devices provide real-time L-R metrics then presumably they can work to remind and encourage the user to increase and balance the power in one leg while riding?

Yes, Paul, I'll be re-visiting a well known bike fitter here (who is also a physio and mad keen cyclist) as soon as I rebuild and get back on the bike.

slogfester · Post by **slogfester** » 19 Oct 2016 06:47

Took delivery of my new 4iiii dual sided crank mounted power meters last week. Just as I went down with man-flu

Just 2 x 10 g (incl batteries), on a new DA crank, means that I have actually saved weight

Connected with ipBike android app (via ant+) I've got more data than I can poke a stick at. Critically it included real time (buffered for 3/5/30 secs) and average Left:Right power balance. Manflu soft pedalling ride gave a average 47:53, which I suspect will get worse when I recover from the flu. Whats worrying is just how hard it is to get a 50:50 (or greater left side) balance. Its as if my whole L leg just doesnt work so well.

I need to go research how best to train to try and fix this?

VERY interesting riding with a power meter. Makes you realise that a lot of your friends/peers who post amazing strava flat segment times are extreme wheel suckers!

Rod Goodfellow · Post by **Rod Goodfellow** » 19 Oct 2016 09:02

I have used a Powertap hub for several years which I found useful.This year I obtained a set of Powertap P1 pedals which link to a Garmin (800 in my case) and and show me that when riding a TT my power is 47% left,53% right.This is due to a left total hip replacement in 1993 (sic).Although interesting it confirms what I already thought. The P1 pedals are easy to swap from bike to bike and have performed faultlessly.You can download the info to Garmin Connect etc and it maps your ride ,graphs speed,power,heart rate,temperature etc.. My son who is seriously into (winning )triathlons was so impressed he got a set and uses them for all his training and competing rides.I bought mine in USA where I spend most of the winter as they were about 15% cheaper there when the £ was at $1.44 and as it is now at $1.22 should be cheaper still.I shall be in USA Nov 14-Jan 11 and they could fit in hand luggage......

laurence_cooley · Post by **laurence_cooley** » 19 Oct 2016 10:46

I would guess that 47:53 is within the normal range - mine's usually about that, too. It will be interesting to see how it changes with the intensity of the ride though.

Yosser · Post by **Yosser** » 19 Oct 2016 22:09

Hi Barry, good to hear that you are back on the bike and raring to go. Re PM’s; superb devices for those interested in the science of both the mechanics of cycling / bikes mechanics and also the physiology of the effects of exercise. Had my first competitive season for 35 yr which has gone better than anticipated. Used PM for all training, Used P1 pedals as they are v transferable from bike to bike and I even took them to Mallorca for use on hire bike. Superb but pricey.
To the point, from the start I was alarmed to find that all my rides were 46/54% bal L/R. Horror. Checked on a Watt bike. Same result and also when using borrowed G3 hum PM (thanks Martin).
Quickly scurried to the net to research how to rescue the situation. (Oh how much faster could I be, if only I had a fully functioning left leg. Right leg looking somewhat smug at this stage). From what I can establish there is little problem with this sort of imbalance. Hard to find any research that even addresses the “problem”. Garmin even laud their PM pedal metrics but have not actually come up with much in the way of usage for this particular stat. I can’t help but feel that an imbalance is the norm. Intersted in what other dual leg users ou there have to say on this matter. Comments folks?
Barry I would suggest that continued use of the leg plus some specific rehab weight exercises will work to bring said leg back to some normality. If there is something of an imbalance that remains you may well have had that from way before your latest woes and you were as strong as the proverbial ox then. Anyway it’s about time something slowed you down!
G’day Baz

Dave

slogfester · Post by **slogfester** » 19 Oct 2016 23:45

Thx for great comments.
Yes, Dave, being right footed/sided, it was probably always thus. I guess I was a bit paranoid because after my back ops my L leg became very weak; couldn't even stand on it alone. So perhaps, after 9 months of intense yoga/pilates/swimming rehab it has recovered better than I thought and that really its not a 'problem'. I was exactly the same as you, my R thinking, 'yeah, get the bludger L working, I've been hawling his arse for years'! Free watts in the offing!
Anyway, I am still soft pedalling due to manflu, so will see how this pans out. I suspect its only post 'race' that you really see the true balance.
It is remarkable that there appears to be so little research in this field.
And don't worry Dave, age is doing a pretty good job of slowing me down

Congrats on the return after 35 years; I'd like to witness your sprint finishes next year.
Cop u lator, maties

laurence_cooley · Post by **laurence_cooley** » 20 Oct 2016 07:57

Rod Goodfellow wrote:I bought mine in USA where I spend most of the winter as they were about 15% cheaper there when the £ was at $1.44 and as it is now at $1.22 should be cheaper still.I shall be in USA Nov 14-Jan 11 and they could fit in hand luggage......

Unless I'm misunderstanding something, surely things bought in the US will be more expensive when converted to pounds as a result of that fall?

Rod Goodfellow · Post by **Rod Goodfellow** » 20 Oct 2016 08:49

Laurence you are right,I wasn't thinking clearly.however this is offset by the strong dollar reducing the price of imports there from Taiwan etc.. I'm still living on the remnants of $s bought about 3 or 4 years ago 2.01$=£.

laurence_cooley · Post by **laurence_cooley** » 20 Oct 2016 10:46

Rod Goodfellow wrote:I'm still living on the remnants of $s bought about 3 or 4 years ago 2.01$=£.

Those were the days!

slogfester · Post by **slogfester** » 22 Nov 2016 06:52

Starting to turn the pedals in earnest now that manflu is abating (turned out to be infected sinus). Early look at data suggests that balance degrades from c. 48:52 (L:R) to 46:54 when I increase the average power (effort) for a ride. I suspect it will get more unbalanced when I get back to full weekend warrior mode and beyond.

jdtate101 · Post by **jdtate101** » 22 Nov 2016 18:28

Barry,

An unbalance is normal due to your brain favouring one leg (ie being right handed and right footed). You can train it to even things out, but to be honest as long as it's within a few % of 50-50 I wouldn't worry.