I'd start by reading this if you haven't already:

http://www.dcrainmaker.com/...ide2014-edition.html

My experience is mostly with wheelhub-mounted powermeters (aka the powertap).

The main thing to watch out for is the spline pattern on the freehub. The freehub is the cylindrical thingy that your cassette (rear gears) slides onto. For the most seamless swap, you'll need the powertap freehub splines to match whatever your cassette is. Spline patterns have names like Shimano or Campagnolo. This article has lots of relevant pictures and instructions about cassettes and freehubs: http://www.slowtwitch.com/...o_-_Part_2_3257.html. Powertaps are usually purchased already "laced" (attached) into a wheel, pretty much ready to ride.
Here is an example powertap in the classifieds:
http://forum.slowtwitch.com/gforum.cgi?post=5268513;sb=post_latest_reply;so=ASC;forum_view=forum_view_collapsed;;page=unread#unread [already sold]

Someone else will have to chime in with compatibility requirements for crank PMs.

As for whether to go crank or hub:
-Crank PMs let you switch rear wheels from training wheels to race wheels and still have power, but are a bit of a pain to swap onto a new bike.
-Wheelhub PMs let you swap power onto different bikes easily just by putting the wheel on the new bike. I enjoy loaning my powertap out to my power-less friends during the winter, since I ride indoors on a CT. The downside of course is that your powertap wheel might not be ideal for racing (though this is fixed by getting a wheelcover like at http://www.wheelbuilder.com)
-Pedal-based PMs kinda give you ease-of-changing bikes like wheelhub PMs AND the ease-of-changing wheels like crank-based PMs. Though I've heard the calibration steps for Garmin Vectors can be pretty involved, so their ease-of-swapping may not be as good as just swapping pedals.


Connecting technology:
-Almost every powermeter nowadays will communicate via ANT+. This will let them talk to a headunit (bike computer). If you want to use Tour de Giro or Trainerroad or other Mac/PC applications, you'll need a separate ANT+ USB stick that plugs into your computer and gives your computer the ability to talk to the powermeter.

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STAC Zero Trainer - Zero noise, zero tire contact, zero moving parts. Suffer in Silence starting fall 2016

Haven't pulled the trigger yet but have done a lot of research and will probably buy in the next few weeks. Everyone has their own opinions so it is very difficult to get actual answers to the basics since everyone thinks they are right and really, there are few "right" answers. Personally, I'm going with a crank based PM but, I'd never tell anyone their choice was wrong ;-)

Here is my take on the basic issues you need to consider:

A powertap (wheel hub) is probably the best bang for the buck BUT it means in all likelihood you are limited to training and racing on the same wheel. IMHO it is the way to go IF a) you need a new wheel AND b) you don't have special race wheels. Compatibility is easy - the wheel will fit any road bike. The only issue is to get the type of hub that matches your cassette type. It either Campy (rare) or Shimano (vast majority of bikes and probably what you have). (I'm not going this route because I switch wheels often).

Crank based PMs are generally regarded as the gold standard but they can cost a bit more (or a lot more) although if you shop hard or go used they are not pricy. The only disadvantage is it can take some work for a newbie to figure out exactly what you need to match your bottom bracket and bike. Not too mysterious but at a minimum you need to know what type of bottom bracket you have. And while the install is easy for anyone who works on bikes, it does involve taking the crank off and maybe doing something with the bottom bracket so if that is not your bag, think twice.

Crank arm units (i.e. Stages) - easy to install and despite some people freaking out about it only measuring one side, everyone I know who has one like them. (This would have been my first choice but it turns out I have one of the few bikes that Stages does not fit and I do not want to wait for the new 4iiii which will not be available until spring).

I recently went through the same thing you are going through now. I don't wrench my own bike and I can't tell you the difference between the various crank...stuff. ie: english or italian threaded, bb30 vs GXP, bottom brackets etc. Basically, it just gives me a headache.

Long story short, all I can address is Quarq (crank based) and Garmin Vector (pedal based). I eventually wound up going with the Garmin Vector because it was 1) significantly cheaper 2) provided more information (which I will most likely ignore) and 3) I could install on my own. I truly wanted the Quarq but if I bought it I would have had to buy an additional bottom bracket (or something like that), pedals and paid someone to do the install. If you go the direction of the Quarq they have excellent customer service and will walk you through everything you need (bb30 or gxp, bottom bracket etc).

Looking all the way back to when I bought the Vectors (last Thursday) I would probably get the Vector S (single side power) instead of the full vector set I purchased. The main reasons I would choose differently are that I'm not nor will ever be an elite cyclist (I am really good at going downhill), it is $600 cheaper and I primarily use power for trainer road workouts.

As someone mentioned above you will need an Ant+ stick for your computer if you want it to pick up any of your Ant+ devices. ie: heart rate, power, speed/cadence etc. If you have a newer Garmin you should already have one. If not you can get one for a decent price at the link below.

http://www.ebay.com/itm/281221176713?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I've had both hub and crank based PM's and would recommend a crank based unit. Primarily because it doesn't limit you to one wheel set. In my case I'm a roadie who does an occasional ITT to verify how much I suck.:-) Rather than riding around on my 100mm rear wheel all the time my Quark allows me to run a shallow wheel for training and then a deep wheel for the race or a disc etc... Further, I have 1 crank and 2 bikes (both BB30) so all I need is an 11 hex wrench and move the PM from bike to bike depending on which one I want to ride. Ideally, I'd have a 2nd Quark but, I'm sort of cheap in weird ways I guess...

You didn't mention if you had a road bike or not. My decision last year to go with crank based (Power2Max) was pretty simple. I have one bike and switch out wheels. So I got a crank based and never have to mess with it. On a side note, P2M gives me cadence without a separate magnet, but I digress.

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Proud Member of Chris McDonald's 2018 Big Sexy Race Team "That which doesn't kill me, will only make me stronger"
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How much are you riding, and what does a typical week look like for you? If you are relatively new, then a PM might be a "nice to have", but simply riding more and throwing in a couple sufferfest videos or one of the online venues a couple times a week might get you just as much improvement in the early stages.

What budget are you looking for? If you can only spend $700 or so, then you are probably looking at a hub based powertap. If you have $2000, then you can do anything you want.

As long as the splines on the freehub (as another poster explained) match your current component set, you should be fine. Your Shiv I believe came with Rival, which is a groupset by SRAM. This means you need a Shimano/Sram compatible freehub, Campagnolo won't work. You can swap out the freehub, but that runs another $100 or so.

The numbers on the chainrings (Front set at the crank) or the cassette (Rear cluster of gears) indicate how many teeth are on the cog/ring. So if you have a 53/39 up front, that means that your large chainring has 53 teeth, your smaller one has 39. Your cassette is probably an Apex 11-28, which was the stock cassette. This means the smallest cog has 11 teeth, and your largest has 28. The middle ones probably run something like 11-12-13-14-15-17-19-22-25-28, which is each of the cogs in order. The larger the number in the front, the harder it makes it to pedal. The larger the number in the rear, the easier it makes it to pedal.

Personally, I don't do my own work on the bike, so I've been hesitant about crank based powermeters. I prefer hub based. If you get a Zipp 404 powertap (Or similar depth wheel) then you can put a cover on it ($100 or so from wheelbuilder) and have 95% of the effect of a disc wheel.

Whichever way you decide to go, I would highly recommend "Training and Racing with a Powermeter" as a co-purchase. This is a great book that will teach you how to effectively use your powermeter to determine your current levels, and how to use your PM for training paces as well as race paces.

John

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Thanks everyone. I ride 4x a week. Usually 3 interval based hour long workouts during the week and a longer ride on the weekends. I don't plan on getting a second bike but have considered getting a set of race wheels, so thinking the cranks might be a better bet. Does crank arm length matter

Crank arm length only matters in regards to fit. If you have an agressive fit and your knees hit your stomach, reducing crank arm length can help. You won't gain any power by decreasing crank arm length

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If you are happy with your current crank arm length (or never though about it which generally means you're happy with it) just go with what you have.

It is only really critical if you go with a Stages since you have to match the length of your other crank arm ;-)

Yes crank arm length matters. If you are happy with how your current cranks fit you then i would recommend getting a set that are of the same length. You also need to make sure you get a crank that is compatible with your bike's bottom bracket.

Wellllll, that sort of depends on whether your hip angle is acute enough to restrict you...


But I mostly agree with the statement.

I have been researching the Stages Power Meter.... I am interested in it! Anyone have any experience with it??

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Hook Em' Horns

If you ride one bike, get a power2max.

If you switch between a road and tri bike, consider a powertap.

Read the DC Rainmaker reviews for more info.

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check out dc rainmaker's power meter review, its very thorough

you have a 10speed. any powertap will work. you have bb30, so if you go crank based you need compatible that. they all work well now.

get a powertap for the winter, can always sell it if you decide you need crank based.

you are also a good candidate for the help of a lbs

If you usually race with same wheels, then wheel-based. If you race same bike, crank-based. I got one set of race wheels I use for anything fast and I switch them out to different bikes depending on the course, so Powertap works great for me.

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I would first start by buying one of the books on power written by Skiba or Allen & Coggan. See if that stuff even interests you at all. If you can't come to terms with what the book is trying to teach, or have no interest in the terminology and methodology of training with power...then it's more than likely you will just end up with a very expensive bike computer.

+1 on understanding how to USE the power meter once you have it, no matter what type. It's a measurement device not an escalator to tri dominance.

Check SRM