4iiii Precision Powermeter

NUFCrichard

I was wondering if anyone else here had got or has ordered a 4iiii Precision powermeter?

Mine came 2 weeks ago and I have been getting used to riding with power since. I am 99% sure that it is reading high, but hopefully it is consistant, which it seems to be. I found it very useful for controlling myself during a very long ride on Saturday, whereas usually I go too hard at the bottom of climbs, I could save myself for later and not feel too wrecked on the way home.

Any other experiences?

cswitch

What makes you think it is riding high, assuming you haven't trained with power before / have no comparison?

I did consider getting one but unfortunately I don't think they're compatible with Rotor cranks arms due to the back face not being flat.

NUFCrichard

cswitch wrote:

What makes you think it is riding high, assuming you haven't trained with power before / have no comparison?

I did consider getting one but unfortunately I don't think they're compatible with Rotor cranks arms due to the back face not being flat.

No they need a flat surface and only work with metal cranks so doubt they would work for you.

I assume it is reading high as I tested my FTP at 324w. I am 77kg and no world beater, so that seems unlikely. It seems consistent though as I can pace efforts off it well.

sloppyschleckonds

NUFCrichard wrote:

I assume it is reading high as I tested my FTP at 324w. I am 77kg and no world beater, so that seems unlikely. It seems consistent though as I can pace efforts off it well.

That would put you on a power to weight ratio of 4 watts per kilogram.

So is it unlikely or consistent? And what does "pace efforts well off it" mean?

NUFCrichard

SloppySchleckonds wrote:

NUFCrichard wrote:

I assume it is reading high as I tested my FTP at 324w. I am 77kg and no world beater, so that seems unlikely. It seems consistent though as I can pace efforts off it well.

That would put you on a power to weight ratio of 4 watts per kilogram.

So is it unlikely or consistent? And what does "pace efforts well off it" mean?

The powermeter seems to give consistent results, maybe not correct, but consistently wrong (so 300w today is 300w tomorrow, even if it is actually 250w!)

4w/kg seems unlikely to me. I have a TT coming up in 11 days, I will see what my time is and compare it to what bestbikesplit had spat out and see if it is in the same ballpark. I believe that most 4w/kg riders are pretty damn good though, whereas I am just a decent rider.

By pacing efforts off it, I mean that I look at what my best 5 minute effort has been, then ride up a hill that takes 5 minutes to climb whilst holding those watts. When I do that it is hard but helps me not go too fast to start with.

harry-s

Thanks for the feedback Richard, - I've got a 4iiii on order, due next month sometime.

It'll be interesting to see how it compares. I use a Wattbike a couple of times a week, and (mostly during the winter) also use some Elite Digital Rollers. The rollers send out a low reading I reckon, - compared to the Wattbike, but they are consistent, and as you say this is the important bit, as I can stick with an evolving program on them. They are very sensitive to tyre pressure though.

Out on the road I usually pace a ride by HR, I'll be curious to see how different, or more effective, pacing by power is, -particularly in TTs.
FTM

motty89

TT times are VERY dependent on how aero you are so probably not a very good indication, i've heard of guys going sub-20 on 300W! Best way to estimate would be to find a long climb with a steady 6-8%(e.g. snake pass), go up it when it's not too windy and work out w/kg from that.

If you're ftp is 325W you'd be one of the strongest guys on a typical club run, but if you ride with racers then i don't think 4w/kg is particularly special.

NUFCrichard

motty89 wrote:

TT times are VERY dependent on how aero you are so probably not a very good indication, i've heard of guys going sub-20 on 300W! Best way to estimate would be to find a long climb with a steady 6-8%(e.g. snake pass), go up it when it's not too windy and work out w/kg from that.

If you're ftp is 325W you'd be one of the strongest guys on a typical club run, but if you ride with racers then i don't think 4w/kg is particularly special.

https://www.strava.com/activities/30433 ... 7164965541
That is the nearest I have at the moment, only 5% but pretty steady for 7.2km.

I just ran it through analytical cycling and got 307.5w whereas I measured 325w

Harry, I have done a bit of a report on the 4iiii here if you want more data. http://nufcrichard.livejournal.com/13445.html:

pippi_langsamer-2

So...they ship these now pre-installed onto a crank arm?

motty89

NUFCrichard wrote:

motty89 wrote:

TT times are VERY dependent on how aero you are so probably not a very good indication, i've heard of guys going sub-20 on 300W! Best way to estimate would be to find a long climb with a steady 6-8%(e.g. snake pass), go up it when it's not too windy and work out w/kg from that.

If you're ftp is 325W you'd be one of the strongest guys on a typical club run, but if you ride with racers then i don't think 4w/kg is particularly special.

https://www.strava.com/activities/30433 ... 7164965541
That is the nearest I have at the moment, only 5% but pretty steady for 7.2km.

I just ran it through analytical cycling and got 307.5w whereas I measured 325w

Harry, I have done a bit of a report on the 4iiii here if you want more data. http://nufcrichard.livejournal.com/13445.html:

Looks like anything but gradual to me, it's got downhill sections in it! Assuming not much of a tailwind your actual wattage would be higher than what analytical cycling says. Looking at some of your other rides i'd say there's no reason to think your PM is overestimating in particular, you're probably just underestimating how good you are.

ravenvrider

So am I right in thinking your ftp test was over 20 minutes giving you 325 watts so if you take off 5% to give you your hour ftp it comes to 308 and a w/kg of 4.0

Or did you do an hour test and got 325w

harry-s

Pippi Langsamer wrote:

So...they ship these now pre-installed onto a crank arm?

The current arrangement, or at least the one in place when I placed my order (about 4 or 5 weeks ago), is that 4iiii will post a pre paid FedEx bag to me, - I put a crank arm in there and send it back to them, they attach the PM, and then post it back.

brettjmcc

Harry-S wrote:

Pippi Langsamer wrote:

So...they ship these now pre-installed onto a crank arm?

The current arrangement, or at least the one in place when I placed my order (about 4 or 5 weeks ago), is that 4iiii will post a pre paid FedEx bag to me, - I put a crank arm in there and send it back to them, they attach the PM, and then post it back.

Yep, someone in work is doing it. Apparently they have customs issues with the adhesive they are using

izza

brettjmcc wrote:

Harry-S wrote:

Pippi Langsamer wrote:

So...they ship these now pre-installed onto a crank arm?

The current arrangement, or at least the one in place when I placed my order (about 4 or 5 weeks ago), is that 4iiii will post a pre paid FedEx bag to me, - I put a crank arm in there and send it back to them, they attach the PM, and then post it back.

Yep, someone in work is doing it. Apparently they have customs issues with the adhesive they are using

Just send it to UK distributor to avoid any customs issue.

sloppyschleckonds

Harry-S wrote:

Pippi Langsamer wrote:

So...they ship these now pre-installed onto a crank arm?

The current arrangement, or at least the one in place when I placed my order (about 4 or 5 weeks ago), is that 4iiii will post a pre paid FedEx bag to me, - I put a crank arm in there and send it back to them, they attach the PM, and then post it back.

Take the opportunity to work on your one-legged pedalling.