Power measurement systems pro's and con's

theautophile · 17-02-2015 5:38pm #1

Quick question for members who are using power meters of one type or another, who's using what and why? Just trying to work out if I should go for a hub based system like Powertap or one of the crank/pedal based systems. I'm assuming that accuracy will be broadly the same across most of the systems so what are the pros and cons of hub V's crank/pedal? Many thanks.

tunney · 17-02-2015 5:49pm

theautophile wrote: »

Quick question for members who are using power meters of one type or another, who's using what and why? Just trying to work out if I should go for a hub based system like Powertap or one of the crank/pedal based systems. I'm assuming that accuracy will be broadly the same across most of the systems so what are the pros and cons of hub V's crank/pedal? Many thanks.

Get a Stages.

godtabh · 17-02-2015 5:54pm

Try searching the form. There is a massive thread already. PS Tunney is spot on

StevieGriff · 17-02-2015 5:57pm

Worth looking into the 4iii Power Meter which will be getting more readily available in coming months and got a solid thumbs up from DC Rainmaker. I know I'm waiting out for one, can't justify the prices of more established brands.

godtabh · 17-02-2015 6:04pm

StevieGriff wrote: »

Worth looking into the 4iii Power Meter which will be getting more readily available in coming months and got a solid thumbs up from DC Rainmaker. I know I'm waiting out for one, can't justify the prices of more established brands.

Have you sent your crank off yet?

lukegjpotter · 17-02-2015 6:06pm

Another thing to consider, if you go for PowerTap, do you use a seperate wheel for the Turbo trainer? No power when turbo training, or riding, without tyre changes.

I have a Stages, only downside is that is kinda limits your bike choice, if you want to upgrade in the future.

Beasty · 17-02-2015 6:19pm

Can't comment on Stages or Power2Max as I don't have them....

Don't like the Vector, other than as a backup (sent one back as it was not picking up data when I knew I was putting out power)

Powertap's a bit of a pain as you are then stuck with the one wheel

Can't recall a problem with the Quarqs I use

Little opportunity to head out on the SRM yet, but after some initial set-up hassle it looks very encouraging

Accuracy varies with the SRM being most accurate. What's more important is consistency which the others provide if properly calibrated, and assuming conditions do not change materially in a ride (although it is possible to recalibrate when riding)

If you want lots of reviews on all systems, check out DC Rainmaker

StevieGriff · 17-02-2015 6:25pm

godtabh wrote: »

Have you sent your crank off yet?

No, gunna hold off on it until March/April. Just to see if the first few batches that get sent out have any problems, and then hold off a while longer for them to iron them out. Don't like buying electrical stuff from phones to game console when they're still in the low serial numbers.

joker77 · 17-02-2015 7:41pm

lukegjpotter wrote: »

Another thing to consider, if you go for PowerTap, do you use a seperate wheel for the Turbo trainer? No power when turbo training, or riding, without tyre changes.

I have a Stages, only downside is that is kinda limits your bike choice, if you want to upgrade in the future.

Huh?

Or... Ride a road tyre on the turbo.

dermabrasion · 17-02-2015 9:07pm

I've a Vector (single peddle). I've had it on the TT (which was on the Turbo), the winter bike and now the good bike. I think that it is generally excellent with my Garmin 500. But, there have been 2 sessions where it (a) did not pick up the data and (b) was under-reporting the effort. Both times I removed it, re-applied it and re-calibrated it. No biggie.
I like it, and will leave it on my race bike for most of the season, using this on the turbo with a crappy turbo wheel. This combined with Traineroad has been a better Turbo season than before.

Beasty · 17-02-2015 11:14pm

Just on the specifics of the Vector. I found 2 issues - one is getting it tight enough and ending up re-tightening it before each ride to minimise the risk of it not recording properly. I ended up with a special torque wrench set-up to get it to the recommended tightness.

The second one only became apparent when I used them on my track bike, when it became clear it was, for brief moments, not recording the power. It's not possible to freewheel on a fixie and it was clealy a fault with the PM, which I then sent back

theautophile · 18-02-2015 12:02am

Thanks for all the replies guys, I guess my main issue is being able to transfer whichever system I go for onto more than one bike. I was hoping for one compelling argument for one system or another. The issue I have with The Stages and 4iiii systems is that they become permanently attached to the crankarms which means if I decide to change/upgrade my bike/groupset, I'm gonna have to fork out all over again. The Powertap option seems like a better solution, but again, do you put it on the training wheel or race wheel? SRM and Pioneer expensive and potentially obsolete within a couple of seasons. I had hoped to hear more positive reports on the Vector pedals as they could easily be brought from trainer to race bike and should last quite a few seasons....... decisions, decisions......

smcclaw · 18-02-2015 8:14am

Why would SRM and Pioneer become obsolete in a few seasons?

Lumen · 18-02-2015 8:34am

theautophile wrote: »

The issue I have with The Stages and 4iiii systems is that they become permanently attached to the crankarms which means if I decide to change/upgrade my bike/groupset, I'm gonna have to fork out all over again

Just move the cranks to the new bike?

It only takes a minute to move a crankset if BBs are compatible. I've done it with my Quarq.

https://www.youtube.com/watch?v=ibycOXD-Mw0

(that is not me)

tunney · 18-02-2015 10:51am

theautophile wrote: »

Thanks for all the replies guys, I guess my main issue is being able to transfer whichever system I go for onto more than one bike. I was hoping for one compelling argument for one system or another. The issue I have with The Stages and 4iiii systems is that they become permanently attached to the crankarms which means if I decide to change/upgrade my bike/groupset, I'm gonna have to fork out all over again. The Powertap option seems like a better solution, but again, do you put it on the training wheel or race wheel? SRM and Pioneer expensive and potentially obsolete within a couple of seasons. I had hoped to hear more positive reports on the Vector pedals as they could easily be brought from trainer to race bike and should last quite a few seasons....... decisions, decisions......

smcclaw wrote: »

Why would SRM and Pioneer become obsolete in a few seasons?

The misconception that the cheaper options will replace the higher end ones.

Stems from a lack of understanding.

Leroy42 · 18-02-2015 11:15am

1st thing is whether you actually need a PM to train properly. It does offer big benefits but only if you understand the data and can adjust your training to deal with what the data is telling you.

2nd - Is any PM better than none at all. I would argue yes, once the data provided is consistent then the actuals numbers themselves are not are relevant. (to anybody but you)

3rd - Are the top end ones the best - SRM is the gold standard. If you can afford it it is the one to go for, but thats a big if.

4th - In most, non pro, cases SRM is too expensive and you're then faced with having to choose the best option for the money. Like in most things you have to make a trade off to get the price you want.

I went with Stages based on the above. It was relatively cheap. It was very light (20g). While it only measures left and then multiplies and as such the actual number is open to question all reports say that the data is consistent and as such I can use it to compare against previous/planned training. Very easy to swap across my different bikes (they all have Shimano cranks) so I can use it on my training bike and easily transfer it to my racing bike to get the event data (while I don't pay much attention to the data during the race it is good to compare the race data against what I am training for). The PM has given me a renewed focus in my training. Time, speed even HR are now largely irrelevant and I now focus on Watts. I try different watts on different segments to see how I react and working out the sweetspot.

Go for what you can afford. Read the reviews of DC Rainmaker, if he gives it a thumbs up then it is good enough. Whether it is good enough for high end is another matter and again you are back into price. IMO, it is better to go with somehting (once it has been tested) rather than avoid buying one because you can't afford an SRM/Pioneer.

theautophile · 18-02-2015 3:04pm

tunney wrote: »

The misconception that the cheaper options will replace the higher end ones.

Stems from a lack of understanding.

Technology moves at such a pace that I am questioning if the cheaper options will replace the higher end/more expensive options, this is not a lack of understanding it's an opinion gathering exercise that I thought was the point of an open forum?

I take your previous point about simply transferring cranks and agree it is a simple task, however like a number of keen cyclists I do tend to upgrade components on a seasonal basis on 'the good bike', which means I could find myself with a set of cranks I no longer require at the end of the season, but they've got an expensive (relatively speaking) piece of electronics permanently attached, which I would loath to fork out for again on the upgraded set. Perhaps I should just accept this and migrate the old cranks to the training bike......if that's the case I would definitely look at the more cost effective systems rather than the gold standards out there! My understanding is that absolute accuracy is less important than consistent data, so as long as whichever system I go for is reliable, I should be fine.

Many thanks for the imput guys!

Lumen · 18-02-2015 3:17pm

theautophile wrote: »

I do tend to upgrade components on a seasonal basis on 'the good bike', which means I could find myself with a set of cranks I no longer require at the end of the season, but they've got an expensive (relatively speaking) piece of electronics permanently attached, which I would loath to fork out for again on the upgraded set.

Do you really buy a complete new groupset every year?

I think you're looking at it wrong. Power-measuring cranks are an upgrade over conventional cranks. You can carry that upgrade from bike to bike or groupset to groupset.

theautophile · 18-02-2015 3:29pm

Yeah, I do tend to upgrade either the groupset or bike each year, I also run a few bikes, one with Campag, one Shimano and one SRAM and even within that I have a couple of changes from standard e.g. FSA cranks with SRAM groupset as one of the frames has a PF30 BB and I don't want to use adapters. I spend a lot of money on bikes, but simply don't want to spend huge amounts on a single training device that I can't move with my own upgrades. I had originally thought the Vectors would be the way to go, but the feedback has been mixed and nobody seems to be using Powertap anymore (or so it would seem)......

Power measurement systems pro's and con's

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