ibike aero married to an srm?

Again, that was GenII, not GenIII. But you are right, there are better things to do other than pull up old references to iBike.

So on one corner, you have the wired PT where you get reliable measurements from a dedicated rear wheel. Price: $649. On the other corner, you have the iBike GenIII which by most accounts gives you data very comparable to the PT but allows you to use any rear wheel you want. There may be some glitches that might produce erroneous readings here and there, but when averaged out, the power data appears to be as meaningful as what you get from a PT. Plus you can get added information with the aero function. Price: $700. If this was the only information you were given, which one would you go with, putting biases aside?

I was actually set on getting a PT wheel from Psimet until I saw the VeloNews piece on iBike. Needless to say, I am very intrigued by it.

I feel like in a situation where you are comparing one product to another as a "standard", if the standard is the same price or cheaper, why not buy the standard?

Well, one good reason would be that the other product offers benefits that the "standard" may not for the same price. In this case, it is being able to use any rear wheel you want plus no wires.

Now I am starting to sound like a shill for iBike.

Where are you getting the $700 from? the price of the regular wired iPro is a little over 400, and a little over 500 for wired with cadence. It starts going up a lot after that, but I really didn't see the point. I have ridden long enough to be comfortable with my cadence, and there is only 1 wire on the wired version, and that's to the fork.

Oh yeah and the interface sucks. If they just put a wind speed sensor in a Garmin or a Joule, that would solve the virtual wind tunnel problem.

The average power over a ride is not particularly meaningful. Before I got my Quarq I was trying out the power track plugin for SportTracks. After I got the Quarq, I ran the plugin on some rides with real power data to see how close it was to reality. I found that the averages were actually pretty good, but the details were off. The useful training information is in the details.

That only applies when paired with a real power meter.

The iBike looks good on paper. It doesn't seem to hold up to reality. Real-world, long-term use.

I don't mean average power over a ride. Isolated spikes of data are easily averaged out if surrounded by a sufficient number of real data, even for short durations.

Well, if the iBike GenIII works as well as a "real" power meter does as the initial reviews seem to suggest, than you have one unit that does both, right?

Well, you gave a couple negative examples but there also seem to be plenty of positive reviews. I guess it comes down to what your expectations are.

The average over sufficiently long durations seems to get you in the ballpark. If all you do are long durations at isopower, then...

You missed the point. The wind speed is needed to calculate the power. When paired with another power meter, it can use the wind speed to calculate your cda. It can't calculate the power and the cda at the same time. The whole calibration procedure is to calculate the cda, that's why you do a coast down, so the power is known (to be zero).

Find real people who have used them long term and get back to me.

You are right; I just realized it will only give you a point in time reading of your drag coefficient when you are coasting. But this would still come in handy to see how different positions / gear affect your CdA.

I plan to do that myself; I will be sure to post a detailed review complete with data files. But not having used a PT or similar before, I guess I won't know any better...

I really didn't mean this to be adversarial. And honestly I think I've given the Ibike more credit than a lot of people who dismiss it completely out of hand.


All that said, I think you're seeing a broad consensus in this thread, and other power meter threads, that the Ibike just isn't where you want to spend you money, particularly now that there's a relatively affordable PT option.

Note that even many of the people that post relatively favorable reviews of the Ibike for some reason are no longer using it.

So you can take the accumulated experience of people who have been trianing with power for a number of years, or you can spend the money that would otherwise buy you a nice powertap and experiment for yourself.

I will start with the iBike Sport; if I hate it, I will be the first one to admit it and I will end up with a very expensive speedometer on my bike :)

I love my tubeless compatible wheels too much to give them up.

So what you really need is a Quarq!:)

I think you may find the Ibike turns out to be a gateway drug.

We're just trying to hook you on the hard stuff right away,

Oh God, don't tell me that. Next thing you know, I will have an SRM, a second SRM, and a second bike for the second SRM (whatever would I do with if if I didn't buy a bike to use on my power meter?)

You got that right.

Repetition is the Mother of Comprehension.

You got that right.

Merlin, sounds like fa63 has made up his mind about getting an iBike, so let him enjoy that. iBike's marketing targets exactly the segment of cyclists fa63 falls into, which values mobility and simplicity. Accuracy be damned.

You got that right.

IBike -vs- PowerTap
 

I used an IBike Gen-3 for the last year. I recently added a PowerTap with a Garmin-Edge into the mix. The biggest issue for me was reliability of the IBike. This is totally subjective of course. I'm a very busy person and don't have time for problems. I have a short window of opportunity to get my rides in. When I get on the bike I just want to go and not be messing around with the power meter.

Here are my observations/ramblings:

1) IBike: Every once in a while I'd head out for a ride and the power numbers would seem off. This was corrected by doing their calibration procedure. The calibration process hads been much improved. It now consists of a tilt test (about 1 minute), wind cal (about 2 seconds) and a 2 mile ride (the time depends on how fast you go). After the calibration it worked fine. I do want to point out that I did not have to do this that often....maybe 5-6 times over the last year. I believe the IBike folks are aware that cyclists just want to get on the bike and go. It seemed to me that all their software upgrades were of the nature to make the power meter much quicker to use. I feel like they did do that. I also want to point out that even if they readings did not seem to be correct that I did not have a problem doing any of my workouts. If you know what wattage you're putting out on a climbing repeat and you notice its 50 watts higher on average you just use that number as your new target.

PowerTap: In the short period of time I've used the power tap I've had no problems. It literally is just get on and go.

2) The IBike folks do have good customer service. They are always responsive to any questions you have.

3) IBike: The embedded software in the IBike head is continuously being upgraded. Sometimes the software release has no issues. Sometimes the software has a bug in it. If any problems are encountered they do update the software. I do want to point out that I never noticed any issues with the power reading between software releases.

4) Concerning power readings...
IBike: The ONLY time I got strange power numbers was when it rained. I don't make a habit out of riding in the rain but when you live in Florida you are bound to get caught every now and then. It seemed to me that the aero sensor would get rain water into it and that's when the power numbers would do a prompt jump up and stay up. I'm talking in the 1000 watt range. It should be noted that once I got out of the rain and the thing dried out the power numbers returned to normal.
Power Tap: No issues with power numbers. Seem comparable to what the IBike was calculating.

5) My power numbers make sense on descents and when I stop pedaling. This goes for both the IBike and PowerTap. There is a slight delay between the calculation and when the screen is updated. I think that's normal.

6) IBike: The coast down procedure is gone and replaced with the calibration ride. I'm not sure if you can even do the coast downs any more. I've never noticed it in the menu system for the head end unit. When I first got the IBike you had to do the coast downs.....now you don't.
Power Tap: You don't have to do this. I put the wheel on and the Garmin found it. Off I went.

7) Ride analysis software. : I like the ride analysis software for the IBike and the Garmin Connect as well.

In general, both off them work with comparable power numbers. Ibike slightly less reliable. Just my 2 cents.

Encore!

http://www.oldbuckeye.com/pontiacsil...ges/encore.jpg

I am not exactly sure what kind of cyclist I constitute, and I am also not sure what you mean about mobility, but I do not really value simplicity (I build/fix/maintain my own and others' bikes) if that is what you mean. I am also an engineer so I value accuracy very much. Anyways, the iBike is still intriguing to me. If the iBike works as mentioned (and a third party comparison by at least one reputable publication is showing negligible differences between the iBike data and other reputable power meters), then I cannot see how a PT would be that much better, at least for what I want it to do. If I get to a level where I think I will benefit from 2% accuracy of say, the SRM unit, then I would go for that. But how much accuracy does one really need?

Power profiling: the first two columns will be empty for anyone with an iBike for power. Note that my training and racing results were completely transformed when I saw what my 5" and 60" power were, and where they went. With the iBike, I probably wouldn't have changed a thing, as those columns would be garbage.

Now, you've said you're not interested in sprinting, so this probably isn't an issue at all.

As far as gadgets go, the iBike is much more impressive than any other power meter. It attracts me as well for this reason, so I just turn that into a yearning for a handlebar wind tunnel...

I briefly reviewed the data files posted on iBikes website; where data from iBike, Quarq and PT were overlaid each other. It does appear that iBike produces readings that differ from PT and Quarq for very short intervals (~5 sec), but there doesn't seem to be any problem for longer efforts. 5" power is not super important to me, but 60" power is (I am a big fan of the 1K attack to the finish during our fast group rides; I think it was you who was a big proponent of that in the racing forums so I have been trying to incorporate that into my training) and I don't see a problem based on my brief review.

I will analyze the data further this weekend to see if anything else jumps out.

if you're WR, though, and you put out 1200W for the first 10", that greatly affects the 1' average. the point isn't that the average over a large group is similar, it's that you want to find out if you're the outlier