[Closed] Talk to me about Power meters

You'll need a large packet of biscuits at the ready.

However, the 4iiii tends to be one of the most reliable units you can buy, and given the price you should buy one.   I have one for 2.5 years now and the only thing I've fettled with is changing the battery - once.

1) Not really unless you have a massive power imbalance in your L/R legs

2) Yes

3) Yes

4) No idea - 4iiii can be upgraded to dual side, not sue how much that is.

Also, one unique feature of the 4iiii is that it has a simple "scale factor" of the power output which basically means you can easily type in a small adjustment to the power output e.g. "98%" so it matches your Tacx.   This means you have the same power in/outdoors

I took a big chance on buying an Elite Direto turbo Xmas 2017 (because I had a ~£100 Elite one from 2006 and it maybe got used ~30 times tops until I gave it away with my old Tricross Singlecross a few years ago), for the up to 14% gradient emulation and the quality power meter, it's been a complete game changer for me in how I try and keep increasing my fitness... So much so I bought a 4iiii last April to have power readings outdoors too.

You've just missed another bargain price at ProBikeKit, they did another promo recently selling the 105 version for £200, I paid ~£340 (which is what they are now).

Evans current have them at £289.

I get 10% at Evans- It's where I'm looking at so about £250

1) As I'm sure your aware they work by doubling one side. My power balance is never perfect and usually around 54 / 46 so say for example at an FTP of 300 it could be reading anywhere between 312w and 288w add in the 2% accuracy margin most powermeters are rated at and the gap could be even further. Whether this matters is up to you? For zwift racing it could actually be a benefit!

2) Sorry had neither so can't comment

3) My two Quarq Dzero's work fine with an old 800.

4) I paid that for a unused Dzero BB30 carbon from the wiggle ebay outlet and paid £400 for a Dzero GXP aluminium from Merlin's so definitely possible.

My L/R balance averages around 46/54, but varies much more than that on short efforts, or when tired. If you're looking more at tracking fitness trends over time though, I wouldn't think it matters so much. A single sided meter will certainly be more accurate than HrTSS.

I had an SRM which didn't quite live up to it's "gold standard" status. Now using a Rotor 2Inpower which has been brilliant, although over budget. I think the single sided Rotors would be within range if you shop around.

get 10% at Evans- It’s where I’m looking at so about £250

If you're talking about the British cycling discount, it doesn't work when buying power meters (I tried). If not, ignore me. 🙂

1) The leg imbalance for most people is so small as to not be worth worrying about (as long as you don't have one leg twice the size of the other!). This is even more applicable if you're just using the data yourself as a guide, rather than having a team of coaches and doctors study the minutia of the data provided...
2) I've only used the 4iii (and one built into my tacx turbo trainer) - thus far no faults or issues when using it on two different bikes.
3) Yes, it works fine on my Garmin 810 - so far the only 'drop out' in readings hasn't been caused by the power meter (the drop out also affected the ANT+ heart rate monitor I was using, so i'm blaming the Garmin, not the crank)
4) Haven't seen any, unless you're willing to go 2nd hand on ebay...

Cheers guys-

I'm surprised the 10% doesn't work on power meters for BC code!

So it doesn't. That's annoying!

Aye, it's buried deep in the T&Cs -

Just show the QR code in store or enter the text version online to get 10% off on qualifying clothing, parts and accessories. (Exclusions: Gift Vouchers, RIDE-IT, FIX-IT, GPS and non-GPS computers, computer accessories/spares, cameras, camera accessories/spares, heart rate monitors, fitness trackers, power meters, turbo trainers) We reserve the right to deactivate your code at any time. Code cannot be used in conjunction with any other offer code. Discount is only redeemable by British Cycling members with a valid membership card which you may be asked to present upon purchase blah blah blah etc

annoying!

I pressed the button on a 4iiii a few months ago and wish i'd done it sooner. I have some specific training goals for this year so is proving to be an essential bit of kit for that and I'm noticing benefits in having power as the central part of my training plan/goals. But in any case having a good idea about power is really useful...HR works in a reactive way....so you are responding to your HR....but once you know your power numbers and know how your HR is affected taking power and all other things into consideration you can ride pro-actively and as a result pace yourself much better and plan your efforts more effectively. I'm still very much a noob and on the beginnings of the learning curve, but I have now adopted the Chris Froome method of riding pinning my gaze on my computer monitoring the power number, especially on climbs!! Obviously don't worry too much about it when out on an afternoons casual saunter, but when on a training ride it focuses your training.

As for the 4iiii and left crank power meter, I think its all you need. I didn't want to spend too much and just having the left hand power meter is good enough and repeatable, which is the most important bit...its irrelevant what the actual number is ultimately...it could be 3 carrots instead of 200 watts, as long as its consistent and repeatable. And so far the 4iiii is concerned it has not missed a beat and its been out in some pretty cold and wet weather with standing water and caked in cow crap off the cow crap coated country lanes I often ride. I think I've probably got about 1000 miles clocked up on it yet (or not far off) and the battery is still at about 80% and it's never dropped out or malfunctioned in anyway.

I find road riding with a power meter helpful for pacing on long climbs or really long days out. I have the 4iiii single-sided Ultegra power meter.

It's a little bit off for me compared to my Tacx Neo, but 4iiii publish a procedure to correct it so that overall the averages tend to match.

Powertap P1s are still ultra-cheap if you can find them in stock anywhere, and have the advantage that you can move them between bikes.

Had several Stages (all died), also powerpod (one died), and have used an Assioma Uno for the past 12 months with no issues whatsoeve -fabulous device compared with Vector 3's. I have also tested it against my Wahoo Kickr and it is spot on. My L/R balance is perfect (tested on Wattbike), but I ride fixed wheel a lot. If yours isn't, what will you do about it? Answer - not much actually 😉 . So in answer to your questions:

1) Single sided is fine
2) I'd avoid Stages, in fact if you want to swap bikes, get a pedal PM instead
3) Works fine
4) Used SRM - I picked one up for £300 on rotor cranks for my TT trike.

I have 2 stages meters. I don't really use them for training in 'zones' as such, but they are brilliant for pacing up climbs.

Basically workout how long the climb will take roughly, then stick at the power you know you can hold for the duration. I use to fade badly towards the end of a climb so using the meter really makes a difference in this regard.

in fact if you want to swap bikes, get a pedal PM instead

Weellll, really?   I swap my crank from my Trainer to my road bike regularly - takes 2 mins.

Single sided are ok if that's what you can afford. I have 3 stages units for 3 years now, all have been fine - (the sram road one is for sale if any one interested as I've just stumped up for vectors)

Outside of budget however I'm very happy with my vector3s a whole heap of extra data. I'm currently experimenting with cleat shims to sort my offset. And you can see the difference each adjustment makes. Also identified I'm 48/52 right bias despite not seeing it on wattbikes.

Not so much flying the stages flag, but I’ve got an R8000 stages single sided meter on my road bike and its been faultless for the last 18months with my Bolt.
Never used a 4iiii so cant post a comparison however.
Not sure I’d ever be able to justify going dual sided for the riding I do, but as above they are very handy things for pacing yourself.

Ive been using power meters for the last 2-3 years. I find they are actually more use for going slower! My recovery rides always ended up going too fast and never recovering..i can now stick religiously to a Z2 scoot and find recovery much more beneficial. Also good on those times when your legs feel garbage at points around a ride, but you can see the numbers that prove you are outing out a certain Wattage... good for morale some days.
I used Stages and found them absolutely fine, but I also have pretty much 50/50 power distribution according to my Wattbike so that maybe helps. I recently went over to Powertap P2s (moved away from Ultegra running gear) and find them really good, I think the P1s can be found on big discount if you hunt around.

I just bought a 4iiii 5800 crank from Mantel for £260 delivered. Took 2 days to get to me. POP to set up and works OK with an 810 and 1000.

Weellll, really? I swap my crank from my Trainer to my road bike regularly – takes 2 mins.

Yup... I swap between:
Track bike, Fixed road bike, Fixed TT bike, TT bike, Recumbent Trike, TT Trike, Nice road bike, Race bike, Old Race bike, Winter road bike.

All the above now only sport one permanent pedal. Not all of the above sport the same BB and crank standards. The Park pedal allan key is fabulous.

Have a look at the sale pages on https://www.power2max.com/en/ and also look for them used. Superb crank meter. A friend at a reasonable level swears it’s better than his SRM. I’ve had no issues with mine.

Not all of the above sport the same BB and crank standards.

Thats fair point of course!

ProbikeKit have currently got 4iii 5800 for £240 and 6800 for £270

I keep getting tempted whenever I see them for 2/3 hundred quid... then remember I have no cash!

If i did get tempted too much I guess that mismatching shimano cranks isnt going to be an issue. I have one sora chainset and one rs500 chainset. Was thinking of buying a LHS 105 chank and swithcing it between the two as and when i need to. As Kryton said, changing LHS cranks is super quick

Phew that's a relief. The Probikekit one is £257 in 172.5. Same as I paid from Mantel last week.