4iii Precision Power Meters

harringtonp

Any users of these out there ? Reliable ? Any water ingress issues like the earlier stages ?

Thinking of buying one. Missed the bargain price on probikekit a few weeks back.

Notice lot of sellers are out of Shimano 105 175mm stock at the moment, if anyone is aware of one of these coming in around the 300E post back here.

Mapaputsi

harringtonp wrote: »

Any users of these out there ? Reliable ? Any water ingress issues like the earlier stages ?

Thinking of buying one. Missed the bargain price on probikekit a few weeks back.

Notice lot of sellers are out of Shimano 105 175mm stock at the moment, if anyone is aware of one of these coming in around the 300E post back here.

My girlfriend has used one for the last year and I had to borrow it recently as my Vector 2S died.

Perfectly fine, power readings were consistent with anything I've done before and it was easy to pair and calibrate. I also cycled through a foot deep flood while out on a spin (didn't tell her!) and it has worked fine since so water ingress is not an issue from my experience.

The Favero Assioma's are worth a look too. About €450 direct from Favero.

harringtonp

Mapaputsi wrote: »

The Favero Assioma's are worth a look too. About €450 direct from Favero.

Thanks though have decided to stick to just left sided crank arm when looking. Have had a P2M for years and was swapping it between 2 bikes. Last year decided to just keep it on the winter/training bike and used summer bike (racing) without power. Miss it a little and could go back to swapping but with price drop in general on PMs, reckon a single sided crank would do the trick... and there is no discernible extra weight too.

tuxy

I have one and am very happy with it. I've had it out in some torrential down pours and never missed a beat.

The older 6800 ultegra is on sale here in 175mm, will work fine with 105 if you don't mind the different colour.

https://www.probikekit.co.uk/cycling-power-meters/4iiii-precision-2.0-3d-power-meter-ultegra-6800/11273319.html

BikeRacer

Without getting too much into it, If you have a P2M on one bike and a 4iii on the other, then you'll either have to do a separate FTP test on each bike or else you'll have an FTP number on one which won't be accurate to the other. I'd save up and get a second P2M.

Takca

BikeRacer wrote: »

Without getting too much into it, If you have a P2M on one bike and a 4iii on the other, then you'll either have to do a separate FTP test on each bike or else you'll have an FTP number on one which won't be accurate to the other. I'd save up and get a second P2M.

As an alternative, If you want the two power meters to match up you can set a scale factor on one of them so that the output values are comparable.

BikeRacer

Takca wrote: »

As an alternative, If you want the two power meters to match up you can set a scale factor on one of them so that the output values are comparable.

That's assuming perfect 50/50 power distribution between your right and left leg, which is extremely rare. Mine can be off by as much as 10%.
I've nothing against single sided power, once the readings are consistent then it doesn't really matter, but in OPs case having both a crank based one and single sided one, you'll question the accuracy of the 4iii on every ride.

StevieGriff

Have about 17,000 KM on my 4iiii at the moment, never a single problem. Battery change every 3 months. Merlin usually have the best prices on them.

harringtonp

Won't really need them to match up exactly as harder intervals will be done on training bike.

Usually try and do endurance at about 200W and 4iii will be fine for that. Doesn't really matter if it's out by 5-10w as either way it's still solid Z2.

And when I blow up racing it will be nice to review after and see what caused it. Again just looking for ball park rather than exact number.

JMcL

Got one from ProBikeKit a few months back 'cause I really needed a device to tell me just how unfit I am. Haven't had any problems with it, maybe about 1000km in so far. I've had it out in wet but not torrential conditions but no problems with water ingress that I can see.

I missed the really cheap offer just after Christmas, but paid under £250 (for 105) thanks to offer codes and "We've missed you" vouchers so it's worth keeping an eye on them

ballyharpat

I got one on the deal, cost about €230, It was working perfect, no problems with water etc, I sold it as I bought a new bike, I bought the Specialized version, it's the same internals, but has a more watertight seal, apparently for the pro teams as they use high pressure to wash the bikes. I think you can get it cheaper than a 4 iii, give specialized Ireland a ring, they can order it, and ship it to you, I got a team discount, but they sell them for €350.-for Ultegra r8000

harringtonp

Just ordered ultegra precision from probikekit. 297 with discount code. It's black and crankset is silver but will live with it

jamesd

harringtonp wrote: »

Just ordered ultegra precision from probikekit. 297 with discount code. It's black and crankset is silver but will live with it

What codes did you use, I am looking for one too.

harringtonp

Think it it was pick10 . They advertised it on the page and I just typed it in, usually they are rejected due to being only valid for certain items but it was accepted

harringtonp

From looking around last week 326-10% is a fairly good price even if it was 105. Though tbh there is practically no difference between a 105 and Ultegra crank arm

jamesd

harringtonp wrote: »

From looking around last week 326-10% is a fairly good price even if it was 105. Though tbh there is practically no difference between a 105 and Ultegra crank arm

My shorter legs add 50€ onto it. Thanks for the code.

harringtonp

BikeRacer wrote: »

That's assuming perfect 50/50 power distribution between your right and left leg, which is extremely rare. Mine can be off by as much as 10%.
I've nothing against single sided power, once the readings are consistent then it doesn't really matter, but in OPs case having both a crank based one and single sided one, you'll question the accuracy of the 4iii on every ride.

Have used it just 3 times and already I'm having to re-adjust numbers in my mind.

Did a 2hr Z2+ spin this morning over a fairly flat course I have used regularly with the P2M. From speed, HR and weather metrics, my gut feeling is that the 4iii reads about 10W lower than the P2M. 189W gave me an average of 30.8 km/hr this morning where as with the P2M, I'd usually be putting out very close to 200W to get over 30.

And yesterday rode TT position (forearms on bars) for 30 mins at a higher wattage and reckon the mental adjustment over the P2M in this case could be 15W or more.

This may be something specific to me as I had a left hip replacement in 2011 and even though its never troubles me, the imbalance may be bigger than for most.

I've also noticed that the variance (3s watts jumping around even though I imagine effort is constant) is greater than the P2M.

Anyway the important thing is that I have a power number in mind that matches the type of training session I wish to complete. It will be more challenging to figure this out as the intervals are shorter and wattage higher.

One question for those who already have a 4iii. Every time I've calibrated it so far I get a reading of 10, is this normal ? The P2M did at least give different numbers back

tuxy

Yeah that's normal returning a value of 10 means it has calibrated correctly. Anything else means there's a problem.

Check out the codes on page 16 of the manual
https://4iiii.com/wp-content/uploads/2017/01/4iiii_PRECISION-PRO-USER-MANUAL-20170123-1.pdf

harringtonp

Ah thanks. The number on a P2M relates to the temperature and I've seen it between -940 and -970. Was assuming 4iii was something similar.

On another note do you get head units that can store 2 power meters and pick up whichever one is active ?

I have to go through the detection process whenever I move by Bryton between bikes

tuxy

I use an old Garmin 500 and can store the info for several bikes and then just select the one I'm using and it will pickup the correct power meter. Maybe your computer has something similar, I'm not familiar with that device.

Boscoirl

Sorry to Bump an old thread.

Anyone having battery issues with one of these?

Have it on my Turbo bike and i am going through batteries like their going out of fashion.

At first I thing it was the cold affecting them. But other batteries in the speed sensor and HR monitor are fine.

Updated the firmware and put the battery from the speed sensor(the 4iii) app reported the battery at ~80%) in last Thursday and it’s flat already. It’s probably my 3rd battery since Oct. and I would imagine I have spent less than 20hrs on the turbo

Mapaputsi

Boscoirl wrote: »

Sorry to Bump an old thread.

Anyone having battery issues with one of these?

Have it on my Turbo bike and i am going through batteries like their going out of fashion.

At first I thing it was the cold affecting them. But other batteries in the speed sensor and HR monitor are fine.

Updated the firmware and put the battery from the speed sensor(the 4iii) app reported the battery at ~80%) in last Thursday and it’s flat already. It’s probably my 3rd battery since Oct. and I would imagine I have spent less than 20hrs on the turbo

Had a similar issue with a Garmin Vector. Is it connected to something that you leave on all the time i.e. a laptop? Turns out mine was staying connected to my laptop dongle even when I wasn't using it and draining the battery. Worth investigating anyway

Boscoirl

Mapaputsi wrote: »

Had a similar issue with a Garmin Vector. Is it connected to something that you leave on all the time i.e. a laptop? Turns out mine was staying connected to my laptop dongle even when I wasn't using it and draining the battery. Worth investigating anyway

Thanks never thought of that. Will check it out

dahat

Boscoirl wrote: »

Sorry to Bump an old thread.

Anyone having battery issues with one of these?

Have it on my Turbo bike and i am going through batteries like their going out of fashion.

At first I thing it was the cold affecting them. But other batteries in the speed sensor and HR monitor are fine.

Updated the firmware and put the battery from the speed sensor(the 4iii) app reported the battery at ~80%) in last Thursday and it’s flat already. It’s probably my 3rd battery since Oct. and I would imagine I have spent less than 20hrs on the turbo

With a Stages pm previously owned i used to take the battery out after each use in winter for the same issue.

CramCycle

I have ordered the dual sided 4iiii, on back order, on the basis that unlike some other dual sided cranks, you can split them and have two single sided PMs if wanted rather than one as a slave.

I expect to pack in my racing career after the first bit of data comes in.

Macy0161

Haven't particularly noticed battery issues with either of my 4iiii. Only time I have is when I was using cheapo Dealz or lidl batteries. No issues with Energizer ones.

Raymzor

Boscoirl wrote: »

Sorry to Bump an old thread.

Anyone having battery issues with one of these?

Have it on my Turbo bike and i am going through batteries like their going out of fashion.

At first I thing it was the cold affecting them. But other batteries in the speed sensor and HR monitor are fine.

Updated the firmware and put the battery from the speed sensor(the 4iii) app reported the battery at ~80%) in last Thursday and it’s flat already. It’s probably my 3rd battery since Oct. and I would imagine I have spent less than 20hrs on the turbo

My estimate is 60/70 hours on energiser battery on single sided 4iii