Has anyone got any user data on the ibike power meter, accuracy, repeatability and general day-to-day usage?
Bill.

I'm not sure if this qualifies as "data" but here is my assessment having used the iBike for the past 7 months. If you have questions about it that aren't answered here you can PM me or just reply to this post.

Pros
*easy install + set-up
*works every day
*use the wheels you want to use
*weight penalty is minimal
*amazingly responsive support from the iBike team
*"wicked" inexpensive as they say in chowdah town
*works with CyclingPeaks

Cons
* looks like an iPod on steroids
* wattage and time aren't on the same screen (needed when doing short intervals
* doesn't have "live" TSS like the Ergomo
* no heartrate
* some have issues with data spikes and drops on descents and rough roads

gene r

Cons:
- Provides less than usable data for portions of rides while drafting, making all numbers from a given ride while with a group essentially useless in post ride analysis. (that is, normalized power, average power will both be off which means TSS will be off which means.. well.. the whole PMC will be poorly reflected). If you never ride with a group or use groups to train with or race in, this might not affect you.

- Cannot change positions without changing effective frontal drag, thus changing calculated power output. If you ride on the hoods 99.9% of the time, this won't affect you. If you like to change positions during a ride, this will effect you.

__________________
Cycling Blog - Training with Power

*I've heard this criticism ("bad data in a pack") but have not experienced it myself. If its off compared to other PMs its consistently off so I have a baseline that is consistent.

*The issue around changing positions is definitely a shortcoming. I ride the hoods 99% of the time. If I were changing positions frequently I'd look at other PMs.

gene r

You would be the exception then. I've seen it reported by others. I think you (Gene) are the guy that didn't like my poo-pooing the iBike on the NEBC list a few weeks ago. I haven't gotten around to getting back to you but I will.

another con: can't be used on a trainer or rollers because there is no "air intake" happening during this activity.

Any time you estimate something rather than directly measure it, you are introducing another set of variables that can produce even more error. People with Power Taps and SRMs have enough issues as it is, why make things more difficult on yourself? And don't try to tell me that you are measuring torque with an iBike because you are not.

Can the power data be downloaded into Cycling Peaks? [Edit] Yes-it is sorry!!

Is data like grade, etc downloadable into any gps type software to analyze or make maps/graphs later?

The most tempting thing for me is the weight savings over my PT set-up and the ability to swap from bike to bike much easier.


I agree-this unit has a list of cons a mile long though.....

I'm the exception? Don't know if that insight is defensible. That's not been my experience when conversing with other iBike users. Maybe you're seeing/hearing something different.

All I know is when I've compared data with PT users (and run a side-by-side tests with a PT on my own bike) I've seen similar patterns in the data. So the iBike may be "estimating" versus "directly measuring" power, but it does a damn good job of estimating and giving me the baseline I need to measure/manage my training.

I'm not saying the iBike is perfect, I'm just saying that for MY purposes it works. I can discern my FTP and measure progress against it over time. If I were a more serious (and talented) rider I might demand the precision that a PT or SRM offer, but that's not a requirement for me. For others it might be.

gene r

I just thought of another potential problem. Lets say you train on different bikes that have different drag due ot tire size, subtle fit differnces, like going from my cross bike (for commuting and rainy day training) to my road race bike (with 1.25" longer reach from saddle to bars), then using all this accumulated data I set myself up a target wattage for a 40k time trial in a full aero suit, helmet, wheels, etc.


Have I just set myself up for disaster in the TT by over or under estimating my FTP due to changes in aerodynamic drag? I suspect that I will be a couple of lbs lower in drag when in full kit and bike.

Help because the weight savings and other features are starting to appeal to me. On a personal note it sucks though that I will not be ableto sell my PT equipment because I will need it for all the time I spend on the trainer at home (6 to 13 hours a week this winter).

Ray

I have no direct experience with this issue Ray becuase I use the iBike on my road bike exclusively, for now. I just ordered a mount for my TT bike so I'll be toggling between the two bikes once I get it set up.

Others who have used the iBike on their road bike and TT bike store different aero profiles (yes, you can do this), and then switch to the profile that is specific to the bike in use.

If you want input from those that are using the iBike on multiple bikes today you can post your question on the iBike User Community or search the threads as this has been asked by others. Here is the link...

http://lists.topica.com/lists/iBikeProPowerMeter/

Good luck.

gene r

Thanks for the link. I called ibike and learned a WHOLE lot today. Given the time it was very interesting to learn about the ability to do Cd and Crr testing (assuming you can find a calm day and have a laptop) via coastdown tests. very interesting to me since I want to get as aero as I can without hurting my ability to breath and pedal.Though it does sound like my best bet is to have both options which is ridiculous from a financial standpoint. PT for group rides, time trials, indoor training and the ibike for solo rides, hilly road races, Cd testing and analyzing routes (hill grades, vertical climbing etc.).

Ray

Like they say Ray, "it's only money". Or as Bob Brinker would say, "your last check should go to the undertaker, and it should bounce."

My favorite bumper sticker besides YOUR PROCTOLOGIST CALLED AND HE FOUND YOUR HEAD, is I'M SPENDING MY KIDS INHERITANCE.

gene r

I've been using the iBike since September and I'll throw in a couple points. Hope these are useful to Ray and Billy:

- regarding the effect of drafting on the unit, I notice little effect in a pack but a definite effect in a small group, like 2-4 people. This is comparing to perceived effort, so take it with a grain of salt of course. My watts numbers seem about 10-20% low in a small group. The theory I've seen floated around is that in a pack, the draft is large and fairly uniform, whereas in a small group, it's small and varied. So the iBike's single pressure reading at the handlebar is more likely to be accurate in a pack. So think about what kind of riding you do before deciding if it's right for you.

- you can use the iBike on a trainer ... sort of. You use it just as a speed recorder and then use your trainer's power/speed curve to convert those speed readings to power readings after your ride. I set up a simple web utility to help with this at:

http://curveship.dyndns.org/trainerpower

Be sure to check the section on that page about accuracy, however.

- It seems that 90% of the people criticizing the iBike on the net have never used one, whereas 90% of the people who have used it like it. It's a good device, and a very good device for the money. But so is a powertap or an SRM, so you need to make your own decision.

Hope that helps. The iBike list glen mentioned is a good resource.

Is the lesser accuracy of iBike use in a bunch such an issue? If you are serious with your training, in terms of power output, why would you want to ride in a bunch and let others set your pace? Isn't a major purpose of PM is to guide you to ride at a particular power level and train accordingly?

Of course, I can understand this particular limitation would restrict its use in a race where you would be in a bunch. I guess the only time to use it would be when you are deep in a bunch or pulling at the front. Ignore data in between.

Does this make sense?

__________________
Morphed Bianchi Camaleonte IV 2006, Ridley Damocles 2006, Garmin, Mac

Thanks for all the input guys. I am going to think about it, as you say the data is patchy but there are many who complain about the Power Tap that suffers from this, that and the other.
For the price ($350 on ebay) it's a long way from the cost of a SRM or the PT and for that matter the Polar.
Bill.

Thanks. LIke everyone else-I have certain things that make an ibike very tempting and certan thngs that make it not so appealing and thats for me to decide (with everyone input of course, which I am thankful for btw).


I have enough problems with my PT that I cannot say that its perfect either (HR, Power dropouts and not having a wheel when I have to send it in to be fixed!!).

Seems that both companies ahve great customer support and are very active in improvinig there systems.

Ray