Metro50

What's up guys.
Been thinking about biting the bullet and splurge for a power meter for the last piece of my build puzzle.

Looking at one in particular, the Garmin Edge 810 with Garmin Vector pedal and sensors.
Narrowed this down to about $1,750-1,800 range for new, but rather spend a whole lot less.

My dilemma is should I get just the single pedal and sensor or dual?
Clearly it's better to get dual pedal and sensors, but the million dollar question is IF it is justifiable?
Any current or past users to this particular setup in single or dual configuration?

And, any other power meter setup models in mind such as the STAGES power meter or PowerTap hub type?
I rather bypass the Powertab configuration as I've finally purchased my carbon clinchers regretably.

I'm all ears. Any opinions or direct links would be grand.

ljsense

Why not buy something fun or useful instead.

What do you want a power meter for?

Let's say you do a race. You see all this data. Big spikes, troughs, what have you. You average 325 watts. You want to win? Next time average 305 and don't look at the thing.

Intervals, you say. Measuring effort and exertion. Training effectively. Ok, fine. But give me a bit of a break. Get completely lean first. Ride 15 or more hours a week.

You want the data or to post to Strava. These are the most committed power meter users. It's a whole thing. I just don't get these people. Race, don't virtual race.

So my advice is just screw it unless you're obsessed with Strava and numbers and then you're in sad company. You've made a video game out of what actually is an awesome real life experience.

K.Katso

I'm a PowerTap user, but I have two friends who are also training with power meters. One has the Stages (crank arm-based, left crank arm only) and the other has a power2max (crank spider-based). I just built a new bike, and I'm kinda regretting not just having them install a power2max at the same time. The PowerTap is convenient if you have multiple bikes for which you share the same wheelset, but exactly the opposite if you have several wheelsets for the same bike. I've got 3 bikes and 6 pairs of wheels, but only 2 sets have a PowerTap. As much as I like the PowerTap, I honestly wish I would have just put a crank-based meter on all of them.

kingfishr

I have the Garmin Vector and find it very useful, but the dual pedal is definitely a luxury. Get the single pedal set and you can always upgrade if you find a good reason. At 56 years of age and after riding a road bike for 35 years I find a power meter helps me pace myself both in time trials and when doing single or double centuries, as well as being a useful tool during training...

chaadster

Having power is a great tool for improving your training and riding.

Although I don't have any experience with the Vector/Vector S, I'll be reading with interest because I'm in the same boat, trying to decide between those two.

The crank systems are out for me, because I have 2 bikes that I'd like to have power-enabled, and the pedals seem like the most convenient way to go in that regard. I have an old Powertap wheel set for one of them, but it's not my preferred wheel set, and is not compatible with both bikes, so that will probably be sold or relegated to simple stationary trainer duty.

The thing for me is that I do most of my power training on a Cycleops PT300 Pro stationary bike with Powertap, so I wonder if the single Vector S is accurate enough to let me work to my training numbers outdoors?

RChung

Depends on the BBs. If your BBs accept an adapter, that could allow you to use a crank system. Even if you're using Vectors, it's often easier to leave the pedals on the cranks and swap the cranks (if the BBs are compatible) than moving the pedals themselves.

Working to your training numbers? Probably. Training to levels is one of the least demanding things you can do with a power meter -- you can actually do a not bad job at training to levels even without a power meter, so a power meter that doesn't produce the highest quality data isn't that critical. If you were doing something more demanding, the S (or the Stages, or some of the other lower-end offerings) may not suffice, but not everyone does those things.

FLvector

If you haven't read DC Rainmaker's Power Meters Buying Guide, that would be a good start. It depends on your goals, how many bikes you ride that you want with PM's, the number of wheel sets you frequently use, etc. I'm currently using the Stages PM and pleased with the data that it gives me. Also, ask around to those that you ride with that have PM's and get their opinions. The Garmin Vector does sound like a good choice if you have a few bikes and don't mind switching it back and forth.

carpediemracing 

I can't easily find the study but there was some kind of peer-review type test (i.e. not a blog) where the people running the experiment caution relying on Vector power data. I read it recently so it was probably linked from Doug Report but I can't find it.

Personally I'm curious about the 4iiii Precision as a low dollar, many bike powermeter (tandem, track, mtb, the Missus's bike). Currently I'm running a pair of wired SRMs on my regular bikes (both similar use bikes, the one I'm not on is the backup).

carpediemracing 

Some people like data, even if it doesn't relate to much else outside of one's own environment. I used a G-Tech RR in my car (until it broke). It's basically a powermeter for the car, measuring G force and stuff. I definitely don't race my car but I liked looking at the data and seeing how things compared when, for example, it was wet vs dry (I learned a lot), cold vs warm, etc.

Likewise I use an SRM but I don't use it for training and I don't use it for racing. I look at the data after the fact and after 6 years I have some idea of where I am fitness-wise in very broad terms. Also, unlike cars, where you can get an idea of where your car stands in terms of HP, torque, G force, weight, mpg, with riding there's no way to get an idea of where you sit relative to others.

If I could do 300 watts for an hour I'd be a monster on the bike.

chil2makefun

I have a garmin 810 and had to make the exact same decision. Finally I chose to order the S version for several reasons. First of all, it will be my first power meter so I didn't want to spend a whole lot on it. Second of all, if I later would chose I actually needed the two sided measurement I can still upgrade to it. But most of all, knowing your left/right balance is nothing but a fun fact in my opinion. Most of us won't really have a very big imbalance to begin with so most of the people don't really try to balance it anyway. And in some cases the ones that actually do try to balance it start to put out less power because they're holding back with one leg. So I actually don't see the reason why I'd pick the regular version over the S version. And even if I would see some added value it still wouldn't justify that much of a price difference in my opinion. As far as stages goes, that wasn't an option for me since I want to use my powermeter on both of my bikes and one is campagnolo and the other one is sram (both carbon).

PS: As for the comment of ljsense​, that's the dumbest thing I'll probably hear all day and that's saying something considering it's only 1AM.

K.Katso

I thought it was a little harsh, but I wouldn't read too much into it. He's probably snowed in and going a little bit crazy. Meanwhile we've still been able to ride.

chaadster

Hmm, I hadn't really considered the ease of swapping cranks, probably because I'd assumed my winter bike, a 12 year old Lemond, would not have a compatible option with my BB86 Breezer. I'll look into that. Thank you.

Also, though, the meter swapping would only be seasonal, so off one bike and onto the other in November, and back around in May. Doesn't seem to onerous, but easier is easier...

With regard to working with hub meter numbers with the Vector S, you said "probably" it'll be ok; can you elaborate on that? What issues should I be aware of?

I guess I'd just like to be reasonably sure that, say, a 10s 400w interval on the Cycleops 300PT would be the same as 10sec @ 400w on the VectorS. I assume the VectorS is closer over longer effort periods, and less so over short period because of the estimating.

Does that sound right?

Metro50

Didn't think I would get the 5th degree on one not using a power meter in it's entirety.
But, ljsense clearly you haven't done research on a power meter enough.

Sure, what you say is true train more etc. etc. and you'll get better results. But one needs to know how much power they are putting to record
there improvements based on watts. Why do you think pros use this method? not for their health I can tell you that.
Cadence and heart rate is ok but you never really know your results accurately.

Metro50

K Katso that's all in all great, but what about the results in which benefits better
or the strong points of the power meter you use etc?

Metro50

Thx kingfshr I will keep this in mind.
Any input of the dual sensor benefits that comes to mind?
I find myself always wanting to get the best or 2nd best as long as it's beneficial enough.
With that being said if I'm training more for stamina, efficiency and just a 40k race is the single sensor enough?

Metro50

chil2makefun interesting in what you say.
Makes sense if one were to see another leg putting out more effort they'd slack off on the other leg.
But, think you said the reverse though. The Vector S is a single pod unit.

Anywayz, thx for all the feedback. I'm starting to lean towards the Vector S and Stages.
Will post any updates, so keep the comments rolling guys.
My ears are still finely tuned in. lol

Silvercivic27

Just buy a quarq and be done with it.

RChung

Well, we know bilateral asymmetry can vary with power, with cadence, with crank torque, and with fatigue, and that the amount will vary by individual. I have some data from a guy doing trainerroad pyramid intervals with a Stages and a PT (not a 300PT but obviously they're related, and this was indoors on a KK trainer, not outdoors). On the way up the pyramid there was a different relationship between the Stages and the PT than on the way down -- however, the wheel speed agreed with the PT power reading (that is, X mph showed the same power on the PT whether going up the pyramid or down, but not so for the Stages). But the difference in power on the Stages for the same mph was something like 4% between going up and going down; the problem was it meant on the way up the Stages was reading around 3% lower than the PT but on the way down it was reading 7% lower [The % error was averaged over the steps; it varied from step to step and wasn't a fixed 3% on the way up and a fixed 7% on the way down]. This was a problem for him cuz it's a situation where accuracy, not just consistency, matters -- in pyramids, the steps should be the same size (or close to it). That said, most people don't do pyramid intervals. If you were outdoors and doing long intervals at ballpark FTP I'd say you'd be okay. You might even be okay with pyramid intervals if you're not finicky about the step size. Or you might not have his bilateral asymmetry, and you could be perfectly okay.

Trainers, btw, tend to be a pretty "clean" environment for doing comparisons. Almost all PMs work pretty well when compared on trainers. Problems, if there are any, tend to reveal themselves when you take the PMs outside in the cold and wet and on bumpy roads, and work them out at high torque at low rpm or low torque at high rpm (or high torque at high rpm).

achoo

That might be the most condescending post I have seen on BF.

Wow.

Simultaneously arrogant and dismissive.

Sheesh.

When are you turning pro and winning the TdF?

RChung

Hmmm. I'm disappointed. I've been accused of writing the most condescending posts seen on BF.

TrojanHorse

Step up your game!

As for power meters, I recently acquired a Quarq SRAM red for just over half price. Chain love had a bunch of them. Scour fleabay and see if you can get lucky. If you have a compatible crank, stages is probably a good way to go and not terribly expensive.

I also have a power tap rear but wanted to be able to switch between wheels, sounds like you're in the same boat.

And as for the above post, power meters are BOTH fun and useful. Win win! Heck, you don't need anything nicer than a GMC denali unless you're planning on entering the grand tours, right?

kingfishr

No benefit so far. As mentioned above it is easier to switch the entire crank than the pedals since they need to be carefully torqued, and once you retorque you might still be slightly off compared to previous rides. I have both a Quarg and the Garmin Vector. I think I prefer the Garmin overall, but only because I can in fact switch between a normal and compact crank if the ride calls for it, whereas with the Quarq I am stuck with 53/39. In retrospect a compact Quarq would have been smarter, but would still mean having to switch chainrings if I wanted to have fullsize vs compact...

chil2makefun

I know the S version is the single pod unit because that's the one I ordered Anyway you get my point. If you decide to buy the garmin make sure you use a decent torque wrench to install them. DC rainmaker did a test and installing them by feel (read: incorrect troque) could leed to inaccuracys up to 30 watts. So if you don't already have a torque wrench, a park tools tw-2 or something like that would do the trick just fine. You'll need a crowfoot as well.

chil2makefun

One more thing though, if you go for the S version you will not be able to use cycling dynamics. But still not worth if for me

grolby

This might actually be the worst BF post on power meters I have ever seen. And I've been around the BF block a few times.