"The 33"-Road Bike Racing - iBike Accuracy?

Hey, maybe I don't get power meters, but relative power is all that matters right? For instance, if your power meter reads 200 watts when calibrated correctly that doesn't necessarily mean you're putting out 200 absolute watts. So, if you do the same ride and your power meter reads, let's say 250 watts, its 50 watts higher than the last effort meaning you've improved. Isn't that the concept behind power training? So, with that in mind, would that mean that cheaper power meters like the iBike, when calibrated and used correctly, are just as effective as a Powertap or SRM? Thanks in advance.

I meant for this to be in the Road Cycling forum, could it be moved?

Hey, maybe I don't get power meters, but relative power is all that matters right? For instance, if your power meter reads 200 watts when calibrated correctly that doesn't necessarily mean you're putting out 200 absolute watts. So, if you do the same ride and your power meter reads, let's say 250 watts, its 50 watts higher than the last effort meaning you've improved. Isn't that the concept behind power training? So, with that in mind, would that mean that cheaper power meters like the iBike, when calibrated and used correctly, are just as effective as a Powertap or SRM? Thanks in advance.

I had an iBike for a couple of weeks. Sold it. Useless for me. But the roads around here are rather rough. Still, the PowerTap is like a friggin Nasa Instrument in comparison. The PT actually works, very nicely I might add.

I'm going to suggest you look up older threads regarding iBike. I am personally just too tired to explain this [i.e. beat this dead horse] further.

-bullseye

iBike. iBoughtIt. iSoldIt.

iThinkThat'sAllYouHaveToKnow.

I'm told by a guy who works on R&D for them that with the stem insert to absorb vibrations their consistency has been greatly improved. Still, it seems to be a glorified toy than an actual power meter.

iBike:

http://www.mrtoys.com/f-22-raptor-jet-12-volt-ride-on-plane/pics/F22-Raptor-12-volt-rideo-on-plane.jpg

Power Tap:

http://www.dudes411.com/planesF22Raptor.jpg

Your move kid.

Hmm... I'll have to look around for more information, but from what I gather, the iBike does calculate power, but not consistently. I'm thinking a used PowerTap will do the job much better and for not much more cash.

Hmm... I'll have to look around for more information, but from what I gather, the iBike does calculate power, but not consistently. I'm thinking a used PowerTap will do the job much better and for not much more cash.

Go to www.ibikeforums.com and read the forums for up-to-date information. Most of the stuff on this forum is dated.

@Pcad: we understand what you're saying. You don't need to most endless similies and metaphors regarding your loathing of the device. Everyone has gotten your message a long time ago.

I could never buy a powertap as I already have way too many wheelsets.

I could never buy a powertap as I already have way too many wheelsets.

+1.

To be honest, the Dura-Ace SRM really appeals to me, but it's too expensive and I change rings on my cranks periodically--don't know if that would affect the SRM crank or not... maybe not, but it doesn't look like I'll find out firsthand any time soon.

I have 2 years of data from the iBike Pro and now I'm compiling data from the iBike iAero and all I can say, from my humble experience, is that it just keeps getting better (i.e., more precise), but it has always been -consistent- for me.

Having said that, if one doesn't have the discipline to calibrate the tilt and wind offset on each ride and allow the device to acclimate to the riding environment, you -will- get errors, but now they can be corrected post-process, so at least you can get a better idea of your training load when you drop the file into WKO+.

This is from a 2+ hour ride. About 60% solo, 40% in group. Rolling terrain. Moderate winds. Mixed roads. I picked this because it seemed to represent a cross-section of my riding habits.

One of the biggest sources of moment-by-moment difference b/w them has to do with response rate -- the iBike responds slower, and actually matches up against the 5-second averaged PT data rather than the raw PT data.

http://www.duke.edu/~aah3/pt-ibike-070825-scatterplot-small.png

(Moving today, so won't be able to reply to questions for a few days.)

This is from a 2+ hour ride. About 60% solo, 40% in group. Rolling terrain. Moderate winds. Mixed roads. I picked this because it seemed to represent a cross-section of my riding habits.

One of the biggest sources of moment-by-moment difference b/w them has to do with response rate -- the iBike responds slower, and actually matches up against the 5-second averaged PT data rather than the raw PT data.

http://www.duke.edu/~aah3/pt-ibike-070825-scatterplot-small.png

(Moving today, so won't be able to reply to questions for a few days.)

This is the Pro, right? It would be good to see some data regarding the iAero once you've compiled enough of it.

The iAero should give accurate power readings if you pair it with a Cinqo. :)

iBike didn't work worth a damn on the chip and seal roads around here. Useless.

I hear gsteinb on the wheel dilemma: that's why I wanted the Ptap on a Zipp 404 clincher. I can train on it every day, but I don't give up the aero wheel factor for racing. Adds some weight to the rear, but that's typically not such a big deal. Don't use it for racing nearly as much as for training anyway, so I'm not sure the wheel dilemma is much of a problem. An SRM has its limitations: you have to pay $3K+ to use it on one bicycle (most of us aren't going to be swapping cranksets you wrenchhead friggin WEENIES). I can use my Ptap on multiple bikes, including my TT bike. Depends on what how you'll use your PM I suppose.

This is the Pro, right? It would be good to see some data regarding the iAero once you've compiled enough of it.

Correct. Looking at the elevation profiles from the iAero's slope info, it's a substantial improvement on the Pro, but I haven't had a chance to run the power analysis yet.

iBike didn't work worth a damn on the chip and seal roads around here. Useless.

My experience was it depended a lot on the bike -- the iBike Pro was right on the edge of working. With my bike (like in the graph above) it usually worked well, even on mild chipseal. Bad chipseal no. But I've seen data files from others where it clearly had trouble.

The iAero, on the other hand, seems to have totally or at least nearly totally (data still coming in) resolved the issue. I haven't been able to make it fritz out on bad roads, and believe me, I've tried.

you got me kinda interested in the I Aero (thinking of putting it on the tandem) But jeez $799?

so does that replace the iBike? and how are they different?

The most sensible, and portable, position for a power meter is in the pedals/cleats. Two pressure meters in the pedals (sensitive in all the axes necessary) and a ring pair down around the BB area for high-res rotational data (maybe 100-200 data points per revolution, for good integration), and a computer unit is all you need. Could likely be designed to be easily moved between different bikes, even without more tools than a pedal wrench/hex key for the pedals.

No need for special wheel hubs, BBs or chain-sensing units. Would probably be less expensive than a SRM too.

someone tried that recently but couldn't get the company off the ground

http://www.microsporttech.com/

so does that replace the iBike? and how are they different?

They've addressed hardware issues that were band-aided with firmware in the iBike Pro. I believe the biggest change was to the accelerometers to address the false peaks on rough roads. Also, the ability to co-operate with a direct force power meter (i.e., wireless SRM or Quarq or any other that uses ANT+ Sport to communicate) was added.

Are they pitching the iBike from their line and replacing it with this? With the trade in upgrade one could buy a used iBike cheap and save several hundred dollars.

Are they pitching the iBike from their line and replacing it with this? With the trade in upgrade one could buy a used iBike cheap and save several hundred dollars.

Yes, and they recognize that. I'm not sure how long the trade-in deal is going to be offered. I thought that there was a deadline.

My take is that they'd prefer iBike iAero over the Pro. For the upgrade, they asked for our old iBike Pro to be shipped back to them. Theoretically, there should be less problems/service calls with the iAero.

end of the month. if I can buy an ibike cheap I may do it.

end of the month. if I can buy an ibike cheap I may do it.

Does Pete still have his? ;)

if anyone does and wants to sell it PM me. otherwise I'll try and snatch one of teh eBay

someone tried that recently but couldn't get the company off the ground

http://www.microsporttech.com/

Too bad. Minoura's Flex power meter (also in the shoe and supposed to be inexpensive) also has dissapeared. Too bad.

Ack. I'm thinking about buying one just in case I go with a Quarq some day.

What's happening to me?

I still don't get the whole 'buy a power meter to add on to your power meter' thing. This stuff is making my head hurt.

Does Pete still have his? ;)

I think I recall him saying he was putting it on his mountain bike.

someone tried that recently but couldn't get the company off the ground

http://www.microsporttech.com/

That's a good idea, but I wonder how they determine rotation... No, you need a hi-res sensor for that as well, at least if you want to be able to extract detailed data such as that offered by the BB-designed solution. A simple cadence meter is sufficient to just mark the start and end of each revolution, with no accurate data resolution possible inside each revolution. A simple timer could give you fairly accurate data if the rotational rate is assumed to be constant throughout the entire revolution.

I still don't get the whole 'buy a power meter to add on to your power meter' thing. This stuff is making my head hurt.

The aerodynamics measurement possibilities are why I'm interested, plus elevation data.

Does it have any merit at all as a consistent bench mark of effort? an iaero can be had for roughly 450 with the trade in prior to the end of the month. that quark thing, or whatever it's called is interesting, but it would require replacing cranks and I think when it's all said and done it would end up being a pretty pricey venture.

From what I've heard, Powertaps, SRMs etc are plus-minus 2 or 3 %. iBike is plus-minus 50%

If you trade in your iBike, you'll still be using your (wired?) harnesses, so I don't think you can expect Cinqo compatiblity unless you get the wireless harness too. And maybe a (not free) firmware update?

I have no experience with the iBike but I've owned/own PT's SRM's and Ergomo's. The latter always gave/give repeatable data, which in reality , is all you need. If you need real numbers i.e. you need to know what your real FTP is for example I'm fairly sure you'll have to get one of the 'Big Three' PM's. From speaking with guys who use the iBike they have complained that the device isn't accurate enough to give repeatable data. From a price standpoint PT's have gotten so cheap I can't see why you wouldn't opt for one of those and know you getting reliable data.

Does it have any merit at all as a consistent bench mark of effort? an iaero can be had for roughly 450 with the trade in prior to the end of the month. that quark thing, or whatever it's called is interesting, but it would require replacing cranks and I think when it's all said and done it would end up being a pretty pricey venture.

Gary, the iBike Pro, for me, was consistent. It appears that the iAero is even better, moving into the realm of being more accurate as well as consistent. This can be proven by using a direct force PM that co-operates with the iAero, something that could not be done with the iBike Pro.

But, if you aren't disiplined enough to do the initial coast-down calibration and ride, the per ride tilt calibration and the per ride zeroing of the wind offset and letting the device acclimate to the environment (btw, this last item affects all other PMs, too), then don't bother getting it. Save your money for one of the "big three".

Read the posts on www.ibikeforums.com (http://www.ibikeforums.com) . The forum is filled with people like me--users--with their praises and their complaints. You can't get a more honest view. There's no second-hand "I knew Joe Blow who had one and said it sucked like a Hoover." It's all first-hand reports, questions, praises, and complaints.

My iBike required constant recalibration, which really was a deal breaker. Training with power is already complicated to a newbie, adding that hassle made it ridiculous.

Here's a review by the owner of a local bike shop:

http://bethelcycle.com/page.cfm?pageID=278

Here's a review by the owner of a local bike shop:

http://bethelcycle.com/page.cfm?pageID=278

>>After two months of frustration I gave up and removed the Ibike. I feel this is a case of a good idea and poor execution.<<

I reached this conclusion after ten days or so. How anyone can deal with this gizmo is really beyond me. But anything is possible. There are people using Windows Vista for God's sake.