any word on the ibike unit?

[MikeMuk]

Redevill: -

I had the same thought re: drivetrain losses and differences/inaccuracies between the SRM and the PowerTap. I've forgotten where, but I asked the question and got the informed response "it doesn't matter". Between a brand new and totally worn (think jumping sprockets - which many people don't let happen) the losses in the drivechain only fluctate a few percent - nothing that could really affect a workout.

Mike

 

[kyzyl2]

Redevill: -

I had the same thought re: drivetrain losses and differences/inaccuracies between the SRM and the PowerTap. I've forgotten where, but I asked the question and got the informed response "it doesn't matter". Between a brand new and totally worn (think jumping sprockets - which many people don't let happen) the losses in the drivechain only fluctate a few percent - nothing that could really affect a workout.

Mike

Hi everyone:

It's John Hamann from iBike.

Well, it took longer than we wanted to get the iBike ready to ship, but they are out there now and we are very pleased with the reports we are getting.

And as Bill said, there were hic-ups with some units but we tried to take care of problems as fast as possible. Again, so far so good!

To answer the question of this thread: there is indeed a small drive train efficiency loss--a very small percentage according to our studies--and we do include it in our opposing force calculations. The number is quite constant until things become badly worn, but most of you will have probably replaced your suspect components long before that point.

Now that we've shipped we get to start doing the fun stuff--adding features, making improvements, introducing product accessories. We already have a lot in the pipeline, so it's going to be a very busy summer for us and hopefully a very beneficial one for our iBike Pro® power meter customers.

Thanks to everyone for their patience and support.

 

[cghebert]

John,

Great to hear that units have shipped! I ordered mine from performance back in April, what is the word on shipments to those and other vendors?
Can't wait to get mine.

Cheers,
Colin Hebert

Hi everyone:

It's John Hamann from iBike.

Well, it took longer than we wanted to get the iBike ready to ship, but they are out there now and we are very pleased with the reports we are getting.

And as Bill said, there were hic-ups with some units but we tried to take care of problems as fast as possible. Again, so far so good!

To answer the question of this thread: there is indeed a small drive train efficiency loss--a very small percentage according to our studies--and we do include it in our opposing force calculations. The number is quite constant until things become badly worn, but most of you will have probably replaced your suspect components long before that point.

Now that we've shipped we get to start doing the fun stuff--adding features, making improvements, introducing product accessories. We already have a lot in the pipeline, so it's going to be a very busy summer for us and hopefully a very beneficial one for our iBike Pro® power meter customers.

Thanks to everyone for their patience and support.

 

[mmerchant]

Hi everyone:

It's John Hamann from iBike.

Well, it took longer than we wanted to get the iBike ready to ship, but they are out there now and we are very pleased with the reports we are getting.

And as Bill said, there were hic-ups with some units but we tried to take care of problems as fast as possible. Again, so far so good!

To answer the question of this thread: there is indeed a small drive train efficiency loss--a very small percentage according to our studies--and we do include it in our opposing force calculations. The number is quite constant until things become badly worn, but most of you will have probably replaced your suspect components long before that point.

Now that we've shipped we get to start doing the fun stuff--adding features, making improvements, introducing product accessories. We already have a lot in the pipeline, so it's going to be a very busy summer for us and hopefully a very beneficial one for our iBike Pro® power meter customers.

Thanks to everyone for their patience and support.

I have the ibike installed and taking it for a ride, i have a trip in france coming up and will be a good testing ground, i'll let you know when i get back!

mmerchant

 

[stevevinck]

I have the ibike installed and taking it for a ride, i have a trip in france coming up and will be a good testing ground, i'll let you know when i get back!

mmerchant

how was the performance on your little trip, can you compare to something else on power

 

[Sillyoldtwit]

how was the performance on your little trip, can you compare to something else on power

No answer to your question steve. Everything seems to have gone quiet on the ibike front. Pity! TYSON

 

[RapDaddyo]

No answer to your question steve. Everything seems to have gone quiet on the ibike front. Pity! TYSON

It's not even obvious how to evaluate the iBike unit. The evaluation I am most interested in is a side-by-side comparison with either SRM or PT on the same bike by the same rider. If I had one (iBike), I would configure it in accordance with the instructions and then ride some high-intensity efforts of various power/duration combinations on different types of routes (e.g., 20min L4, 5min L5, 2min AWC, 20sec NM) under different types of wind conditions. The issue in my mind is how well I can manage power to a pre-defined target. I would attempt the efforts with the iBike unit and then duplicate my efforts with the SRM or PT. Of course, the acid test (for me) would be a route that calls for frequent power changes under the optimal VP pacing strategy (e.g., power changes every 30secs or so). The long, continuous power durations (e.g., 2x20s) should be easy because any lag is dwarfed by the length of the effort.

 

[JIM WV]

It's not even obvious how to evaluate the iBike unit. The evaluation I am most interested in is a side-by-side comparison with either SRM or PT on the same bike by the same rider. If I had one (iBike), I would configure it in accordance with the instructions and then ride some high-intensity efforts of various power/duration combinations on different types of routes (e.g., 20min L4, 5min L5, 2min AWC, 20sec NM) under different types of wind conditions. The issue in my mind is how well I can manage power to a pre-defined target. I would attempt the efforts with the iBike unit and then duplicate my efforts with the SRM or PT. Of course, the acid test (for me) would be a route that calls for frequent power changes under the optimal VP pacing strategy (e.g., power changes every 30secs or so). The long, continuous power durations (e.g., 2x20s) should be easy because any lag is dwarfed by the length of the effort.

A friend of mine just got his within the last week. Just from talking to him on our weekly group ride last week, it was putting out numbers that were what I would expect. In any event, I am going to try and talk him into letting me put it on my bikes to test against my PT and SRM. . . .

 

[stevevinck]

A friend of mine just got his within the last week. Just from talking to him on our weekly group ride last week, it was putting out numbers that were what I would expect. In any event, I am going to try and talk him into letting me put it on my bikes to test against my PT and SRM. . . .

OK JIM WV , the hopes are on you now

 

[Tom Anhalt]

A friend of mine just got his within the last week. Just from talking to him on our weekly group ride last week, it was putting out numbers that were what I would expect. In any event, I am going to try and talk him into letting me put it on my bikes to test against my PT and SRM. . . .

Yes!...Do it! Do it!

We need a set of "Rosetta stone" files that includes the Ibike. Definitely try to put it through it's paces with some steady and highly variable rides.

I can't wait....

 

[RapDaddyo]

Yes!...Do it! Do it!

We need a set of "Rosetta stone" files that includes the Ibike. Definitely try to put it through it's paces with some steady and highly variable rides.

I can't wait....

Again, the test protocol is important. What I am most interested to see is what the actual power is (as measured by a recognized standard such as SRM or PT) when one is attempting to ride a course segment at a specific target power. There are two distinctly different ways to use a power meter. One use is post-ride analysis -- what did I do? The other is to use the PM to manage power during the ride (e.g., high-intensity efforts). I personally could care less what the iBike unit's AP is for an entire ride as compared with the PT or SRM. It could be within one watt and still be useless for my purposes (or anybody I would recommend it to). I care how well I can manage power against a pre-defined target (e.g., 5min @ 120%FT) with typical, variable conditions (grade and wind). And, that is really a function of how well the rider manages his power even with the PT or SRM. Which is why I suggested the test I recommended -- ride a high-intensity effort with the PT or SRM and then with the iBike unit (same effort, same course, same conditions). If one can manage such efforts within a few watts of the PT or SRM, then it is useful for its main purpose -- managing power, real-time.

 

[peterpen]

A friend of mine just got his within the last week. Just from talking to him on our weekly group ride last week, it was putting out numbers that were what I would expect. In any event, I am going to try and talk him into letting me put it on my bikes to test against my PT and SRM. . . .

If you do it, make sure to do rides that include variable road surfaces, from perfectly smooth to as close to pavé as you can find. Also, try and use it in a pack or at least a paceline - preferably a sketchy Cat 4 crit pack with plenty of surging and sprints out of every corner.

From the few reports I've read, the iBike may be useful for people who want to track their wattage on known training routes with predictable conditions. People looking to record data or manage their efforts in real time under the typically variable and chaotic conditions of real-life training and racing might be disappointed with the iBike's inherent limitations.

 

[JIM WV]

If you do it, make sure to do rides that include variable road surfaces, from perfectly smooth to as close to pavé as you can find. Also, try and use it in a pack or at least a paceline - preferably a sketchy Cat 4 crit pack with plenty of surging and sprints out of every corner.

From the few reports I've read, the iBike may be useful for people who want to track their wattage on known training routes with predictable conditions. People looking to record data or manage their efforts in real time under the typically variable and chaotic conditions of real-life training and racing might be disappointed with the iBike's inherent limitations.

Oh, Boy. I am not real good with math and nobody will confuse me with a scientist but I'll try and prevail upon my buddy to loan it to me for a week and put it through my usual rides and interval sessions. The intervals will be interesting as I think it will satisfy RDO's curiosities. I am just as curious with the $ I've got sunk into meters vs. the price of the ibike. Try to get it on and report back sometime next week . . .

BTW, I've paid my dues and in no way will I be riding a sketchy 4 crit!

 

[tigermilk]

Again, the test protocol is important. What I am most interested to see is what the actual power is (as measured by a recognized standard such as SRM or PT) when one is attempting to ride a course segment at a specific target power. There are two distinctly different ways to use a power meter. One use is post-ride analysis -- what did I do? The other is to use the PM to manage power during the ride (e.g., high-intensity efforts). I personally could care less what the iBike unit's AP is for an entire ride as compared with the PT or SRM. It could be within one watt and still be useless for my purposes (or anybody I would recommend it to). I care how well I can manage power against a pre-defined target (e.g., 5min @ 120%FT) with typical, variable conditions (grade and wind). And, that is really a function of how well the rider manages his power even with the PT or SRM. Which is why I suggested the test I recommended -- ride a high-intensity effort with the PT or SRM and then with the iBike unit (same effort, same course, same conditions). If one can manage such efforts within a few watts of the PT or SRM, then it is useful for its main purpose -- managing power, real-time.

Did you see the discussions on the topica wattage forum last month? Someone provided a couple ride files with simultaneous readings from a PT and iBike. I took that data, did some interpolation to get a pseudo-equivalent time sampling, did a regression on the interpolated samples, got lousy results, but provided rationale why that was meaningless (Andy C. should certainly remember that discussion). Depending on the road surface, the comparison was either quite impressive (not just AP for the entire ride, but the entire time history of the data) or unacceptable (good for 90%+ of the ride, but sloppy roads shot power up and totally skewed AP/NP. The discussion gets going at - http://lists.topica.com/lists/watta...t=d&start=42825

The comparison data should still be at http://www.pearlandcyclingclub.org/pt_ibike.xls
and http://www.pearlandcyclingclub.org/pt_mod2.xls

Apologies in advance on the second file since it's just time and power (no graphs). The first one has a nice long graph comparing the 2. Don't pay much attention to the last bit of ride data. The rider reported a mechanical issue which forced him to stop. The phase shifting is due to the 2 devices having different sleep periods.

 

[Tom Anhalt]

Oh, Boy. I am not real good with math and nobody will confuse me with a scientist but I'll try and prevail upon my buddy to loan it to me for a week and put it through my usual rides and interval sessions. The intervals will be interesting as I think it will satisfy RDO's curiosities. I am just as curious with the $ I've got sunk into meters vs. the price of the ibike. Try to get it on and report back sometime next week . . .

BTW, I've paid my dues and in no way will I be riding a sketchy 4 crit!

No worries...just post the files and there'll be plenty of people willing to dissect them!

 

[acoggan]

The comparison data should still be at http://www.pearlandcyclingclub.org/pt_ibike.xls
and http://www.pearlandcyclingclub.org/pt_mod2.xls

There you go with the "eyeball test" again...

BTW, does anyone out there know how the iBike handles braking??

 

[acoggan]

BTW, there's now a topica.com discussion group specific to the iBike:

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

 

[Tom Anhalt]

There you go with the "eyeball test" again...

BTW, does anyone out there know how the iBike handles braking??

I don't know how the iBike handles it...but, maybe I'm being a little dense, but I'm having a hard time seeing how it could be a problem.

Here's what I'm thinking...they've got a wind speed sensor, a wheel speed sensor, at least one accelerometer, and some sort of inclinometer AND a barometric pressure port. Then, they're calculating (based on the coast-down test and the resultant assumed CdA and Crr) the power required to go the speed they're going. Anything that calculates out to an input power of zero or less than zero (i.e. braking) would just be displayed as zero. What am I missing?

 

[acoggan]

I don't know how the iBike handles it...but, maybe I'm being a little dense, but I'm having a hard time seeing how it could be a problem.

Here's what I'm thinking...they've got a wind speed sensor, a wheel speed sensor, at least one accelerometer, and some sort of inclinometer AND a barometric pressure port. Then, they're calculating (based on the coast-down test and the resultant assumed CdA and Crr) the power required to go the speed they're going. Anything that calculates out to an input power of zero or less than zero (i.e. braking) would just be displayed as zero. What am I missing?

Simply ignoring any calculated power <0 W would work in terms of a plot of power vs. time (although what about those times you might be braking and pedaling at the same time, e.g., in the wet?). One of the more interesting features of iBike (software), though, is the ability to break things down into power to overcome wind resistance, power to overcome gravity, etc. - but that only works if you never brake. If you do, then these calculations are going to be skewed, sometimes significantly (e.g., there's one point on my usual weekend ride in which I must brake from ~50 mph to ~5 mph to avoid running a stop sign and potentially getting nailed by a car).

 

[Tom Anhalt]

Simply ignoring any calculated power <0 W would work in terms of a plot of power vs. time (although what about those times you might be braking and pedaling at the same time, e.g., in the wet?). One of the more interesting features of iBike (software), though, is the ability to break things down into power to overcome wind resistance, power to overcome gravity, etc. - but that only works if you never brake. If you do, then these calculations are going to be skewed, sometimes significantly (e.g., there's one point on my usual weekend ride in which I must brake from ~50 mph to ~5 mph to avoid running a stop sign and potentially getting nailed by a car).

Allright...what % of the potential users and what % of the time they use the dang thing do you think your "braking and pedalling at the same time" example would apply. That sounds like a pretty small nit to be picking.

I'm still not following how in your braking from ~50 mph to ~5 mph example the power calculation will get skewed. If the calculation turns out that for the given conditions power needs to be removed from the system, it's just going to display and record zeros and assume that braking is occurring. What am I missing?