Power meter, quarq, srm, what to do?
Since 2010 I have been running two powertaps, one on an aluminium wheel & one on an 808. This year i installed the one from the aluminum wheel on a set of Reynold's assaults and now realize the error of my ways... no way to easily use a trainer tire!!!
thus, I am considering putting a crank based power meter on my Specialized Tarmac Road bike.
so, my questions, as I know next to nothing about crank based PMs
Can I use my carbon Specialized cranks with a SRM or Quarq PM? the pics of the Quarq site & the one Specialized sells that is a rebranded quarq, seem to suggest yes...
is there any strong preference of SRM vs Quarq? if yes, what are advantages & disadvantages?
should i consider the PT pedal based PMs and ditch both of my powertaps?
Should I be considering stages? (clearly can't go carbon crank if I do)
Should i consider the new PT Chainring power meter? this is not compatible with my cranks, so I would have to change that.
Help, questions, random acts of kindness in teaching me would all be appreciated 
Comments
I just purchased a mid-compact for $600 and it includes an FSA crank, praxis chain rings and their PM - not the highest end crank, but suits my needs. Once I get and install, I'm going to sell my 53/39 Power2Max crank w/ praxis rings. Just one more consideration......
I have a Quarq. I went back and forth a bunch of times when researching options. I went with Quarq over PT because I wanted options of switching wheels on my bike (what you are finding now). Of course, I keep the Quarq on my tri bike and do not switch it to my road bike, so this becomes an issue. But, you have that one solved with having more than one PM.
Quarq vs SRM - very similar technology. The biggest factor you will find there is price, SRM being higher. Also, I believe SRM battery must be done by them, where you can easily replace the Quarq battery yourself in 10 seconds). SRM has been around longer, but I'd say that Quarq has taken the market share from them over the last few years. Quarq has made more R & D changes of the 2 as of late. I have used their customer service a handful of times and they have been excellent in helping me out.
The Quarq unit comes as a set (chainrings, cranks, bb, etc). You pick the ring size (compact or standard), cranks length, and bottom bracket type. I've heard of people swapping out cranks or rings on the Quarq, but I would check with them to see if this requires recalibration at Quarq if you plan on doing so.
I've heard good things about stages and have some friends that use them. But I know a few of them who have had issues during races where the signal has been lost. But, I suppose that may be true with someone using any PM.
Hope this helps a bit. When in doubt, read DCR's powermeter write ups...that dude breaks it down better than anyone!
I have a quarq that I move between bikes and it's super convenient for that and I have not had any issues with mine but I agree with Tim a lot of the earlier units had many issues. So Jeremy's call for used current model Elsa might be a good choice and would make it easy to move between bikes as well.
My buddy has stages and has nothing but problems with his and has gone through 3 or 4 of them so far, mostly water damage. This I bet is true for every brand out there though, for each person that has zero issues there will be another that has horror stories so take that with a grain of salt.
If I were buying today I would probably go with Power2Max the Quarq has not given me any issues but price wise they are a bit high compared to others out there.
I put a Stages ($400 deal from Todd @ Trifit) on my Tarmac last month. No issues, but only a month's worth of use so far. It starts up easily, reads to my Joule and Garmin Fenix. I bought a Garmin speed sensor, the new kind which just wraps around the hub once I realised that I wasn;t using a PowerTap, which automatically generates speed.
http://www.powertap.com/product/powertap-c1-chainrings
Also, why pedals? Stoopid easy to move between bikes (Road, MTB and soon a cross bike) and doesn't limit my bike component choices.
Lastly, independent of my research, Tom Glynn made the same choice of the P1's.
I think they expected flawless due to buying the most expensive power option.
Most $$$ not always the no brainer best product.
I know many, myself included, that have been very happy with the $399 stages.
Maybe, it's cuz we have a little dough left over that makes us happier than the SRM guys.
(was & still am happy with my Quarq, also, and still use it on my roadie).
i have a latest generation quarq upgrade. finally this is solid.
i just got stages. only option where i could get 180 mm cranks. fine so far.
the new powertap chaingrings sounds good. versatile as you can swtich to compatible cranks. but note the smallest chainring is 36, not 34. i might consider these sometime because i could get Zinn 190 mm cranks and use these for power.
yesterday, (prior to reading stark's post) I read DC Rainmaker's article on the P1 Pedals
http://www.dcrainmaker.com/2015/08/powertap-p1-pedals-review.html
Clearly the right answer.
I will shortly be selling two powertap hubs!!
anyone know a way of getting the P1s for a discount?? Have already asked Coach Rich to check with Wheelbuilder...
Following... I am just a nudge away from pulling the trigger on the PowerTap Pedals, just one single nudge.
***Nudge***
In the past I cracked a Carbon Powertap wheel my hitting a big pothole at high speed.
I'd say buy your Powermeter for the functionality under most of your base case conditions (bike compatibility, switching between bikes, reliability, accuracy, work in various weather conditions, easy of use, customer service, etc, etc, etc). If you crash, you can destroy any part of your bike or your body... Worry about fixing those problems after they arise. One (Big in my opinion) advantage that the P1 pedals have over the Garmin Vectors is that the P1s do NOT have the little pod thing hanging down that is just asking to get ripped off even if you don't crash. That was a non-starter for me given I was planning to use them on my Fat Bike.
IF you're willing to pay a bit more, the P1s might be a really good choice to use for multiple bikes regardless of compatibility issues. i.e. different Bottom Brackets, 10-spd vs 11-spd, different spindle widths (i.e. Fat Bike vs mtn bike vs. new tri bike vs. older road bike), etc.
As long as they are consistent and you don't have any trouble with drift, etc. Buy what you like.
Could anyone please tell me where the best deals are to be had in the US? I am over in Chicago next week (from the UK) and would like to take advantage of that to get one.
I'm looking into the Stages Shimano Ultegra 6800 power meter or those P1 pedals. I prefer the price of the Stages option though even in Dollars. The Stages one seem to be out of stock in my size (175) on their website though.
cheers
Quarq, Stages, and PowerTap seem to be the most common power meters on the team. Solid and good prices. Stages is really cheap compared to the others but some would argue about the reliability/accuracy. (I haven't had any probs with mine).
Every now and then, an opportunity to hit a special price pops up for the team, usually announced by the coaches or Mariah Bridges, but I don't know if anything is going on right now.
Check the sponsors tab at the top for discounts and there's a relatively new thread in the forums for deals that come and go.
Thanks for the reply Chris.
I'm a bit disappointed with my Fenix 3 for its poor GPS/pace accuracy whilst running and the pain I get when I update my Edge 510 and lose all my settings. I'm voting with my wallet to show my displeasure
I emailed a store in Chicago and they responded quickly initially as I'd like one for my wife as well. Even with a strong Dollar everything is still cheaper over your way.
I'll have a dig around in the areas of the site you mentioned to find out if any offers are current.
cheers
for those that want the end all discussion on power meters, DC rainmaker just posted his annual survey
http://www.dcrainmaker.com/2015/10/buyers-guide2015-edition.html
My issue is that im not confortable installing also... and LBS only have stages available or the #$%#$% overpriced vectors.
I'll either be distraught when they don't work or smug as hell when I test them when I get home next week.
I can go either way on the laptop... P1 pedals run both ANT+ & BT so that works...
The take-home message for me has been: get a really clear idea of what you want out of your powermeter, then go read his blog to see what the options are
Happy shopping!
Angus