any word on the ibike unit?



tigermilk said:
You're completely missing my point. I'd much rather have a large volume of data with varying degrees of intensity and durations to compare post-test. You are trying to characterize the performance of a device, and as such the larger the sample base, the better you can judge that device. It really is as simple as go out and ride and different intensities and durations, compare post ride. If you want to get more info, do one interval with PM#1 as the guide and repeat with PM#2 as the guide. Ultimately, however, it's all about collecting a substantial data set from which to assess performance.

I mean really, does it matter if your interval is done at isopower, a half sine wave, sawtooth, or a travelling salemen shape? Nope. Perhaps it's the engineer in me talking, but really it doesn't have to be as difficult as you make it out to be.
And I think you are missing my point. I don't think anything I say will change that. So, let's leave it there -- we missed each other's point.
 
mmerchant said:
Just wondering if anyone has a take on the new ibike power unit?

mmerchant
just wanted to give everyone an update on the ibike - basically the ibike uses calculations to come up with your power rating - the unit measures incline, speed, wind speed and then calculates your power. now i don't have a power tap or other absolute power measurement system to compare against, but the numbers seem good! i am getting reproducable readings on intervals done on the same day with speed and heart rate staying fairly constant, are demonstrating consistent read outs. calibration of the system is ongoning but the guys at ibike have been extremely helpful.

IMO, watch this thing revolutionize power training, inexpensive, light and so far working well.

mmerchant
 
mmerchant said:
just wanted to give everyone an update on the ibike - basically the ibike uses calculations to come up with your power rating - the unit measures incline, speed, wind speed and then calculates your power. now i don't have a power tap or other absolute power measurement system to compare against, but the numbers seem good! i am getting reproducable readings on intervals done on the same day with speed and heart rate staying fairly constant, are demonstrating consistent read outs. calibration of the system is ongoning but the guys at ibike have been extremely helpful.

IMO, watch this thing revolutionize power training, inexpensive, light and so far working well.

mmerchant
I agree. The few posted side-by-side evaluations wit PT have been pretty good. There are some folks on the iBike Forum site that are having some software issues, but they don't affect everyone, and I'm not sure the are significantly greater than some of the types of QC issues I've seen posted on this site for the PT or the Polar units....and, John and company seem to be knocking these problems down at a pretty good clip...
I had a magnet/sensor that went out after 3 weeks, and the Velocomp folks volunteered to change it out, and did so within 3 days. These guys are all about good customer service, IMO...
Apparently, Cyclingpeaks can now accept and process iBike data, and I look forward to starting with them to optimimize my training.
Like most users, it's interesting to read the opinions, but I think we all look forward to stringent evaluations with other units.

Bill
 
As we've heard nothing about the comparison of the iBike with other more well known power meters, can we assume it doesn't match up? Pretty sad if that's the case, as I was looking forward to buying one and recommending it to Japanese riders and my LBS over here. Ah well!:(
 
Sillyoldtwit said:
As we've heard nothing about the comparison of the iBike with other more well known power meters, can we assume it doesn't match up? Pretty sad if that's the case, as I was looking forward to buying one and recommending it to Japanese riders and my LBS over here. Ah well!:(
You haven't been looking very hard. Try the Power and IBike forums on Topica. - TF

BTW - My take is that it currently is not ready. Can't handle bumps; including chip seal or the vibration at speed. Also, all the features have not been activated.
 
Terry Ferguson said:
You haven't been looking very hard. Try the Power and IBike forums on Topica. - TF

BTW - My take is that it currently is not ready. Can't handle bumps; including chip seal or the vibration at speed. Also, all the features have not been activated.
LOL Thanks Terry, sounds like a good buy, or is it goodbye.:rolleyes:
 
Sillyoldtwit said:
LOL Thanks Terry, sounds like a good buy, or is it goodbye.:rolleyes:

don't know why you're so happy trashing something you don't know ?

I have one , the numbers it give are very much the same as my indoor trainer so I can use it in cyclingpeaks . The bumbs ... yes I might miss 15% of my ride but that is still beter than nothing at all (in my opinion). For a very good price and more important I don't have change any of my equipment (wheels , cranks ,...)

What powermeter(s) do you use ??
 
stevevinck said:
I have one , the numbers it give are very much the same as my indoor trainer so I can use it in cyclingpeaks . The bumbs ... yes I might miss 15% of my ride but that is still beter than nothing at all (in my opinion).
Just curious (not trashing), how does cyclingpeaks handle the 'missed' portions of the ride? Do you still get meaningful (eg.) 20min and 60min AP and NP values, or do the bumpy portions register as zeroes? Or do the bumped-out portions not give any readings (ie, neither time, nor power), meaning that you'd need to add another couple minutes to each 20-min interval to make sure it registers as a 20min point on the charts and such?
 
frenchyge said:
Just curious (not trashing), how does cyclingpeaks handle the 'missed' portions of the ride? Do you still get meaningful (eg.) 20min and 60min AP and NP values, or do the bumpy portions register as zeroes? Or do the bumped-out portions not give any readings (ie, neither time, nor power), meaning that you'd need to add another couple minutes to each 20-min interval to make sure it registers as a 20min point on the charts and such?
According to some users on topica, the worse problem is not the missing sections on bumps, but the fact that the power numbers are wildly off (high) on bumpy roads.
 
I've been using the iBike for a month now and I for one am very happy with the quality of the data (I have benchmarked vs a PT). My numbers according to both devices are pretty much the same (both devices confirm that I suck ;) ).

The roads I ride in S Barbara county vary between relatively smooth and absolutely brutal, and I've not encountered the wild swings in power or total loss of power data that others have experienced.

I am also using CP and it's worked flawlessly with iBike files. Overall I am a satisfied customer and no, I have no affiliation with or economic interest in the iBike franchise.

gene r
 
I've got a couple weeks of use on my iBike + CP. Overall, I'm pretty happy, though there are some issues. Here are some answers to some of the questions, based on my experience:

Data accuracy: I don't have another PM on my bike to compare to, but I've tried comparing the numbers I get from iBike on a few climbs with those from analyticcycling.com, and they generally match up pretty well, within 5%. So, at least on climbs, it seems pretty good. I can't say for flats, but it "feels right" based on RPE.

Data cutouts: My experience, based on the roads I ride, is that the power reading cuts out about 2 to 5% of the time, usually for only a few seconds as I go across some cracked pavement, but occasionally for a while. It helps if your roads are low trafficed enough that you can chose the cleanest section of the lane. Higher speed = more cutouts as well. I rode a brand new chip-seal road, so new I almost slid out on the loose gravel, and the iBike cut out entirely. Older chip-seal roads vary, sometimes OK for 90% of the time, sometimes only 50%.

Inflated power numbers: yep this happens, but it's a small portion of the ride (1% or less, IME) and you know it when it's happening. The numbers aren't slightly high, they're ridiculously high, like 700+ watts. Since they're easy to identify in CP, I just edit the data with my best estimate as to what the real number was. Kind of a pain, but it would be much worse if, say, the numbers were off only a small amount and you never knew if they were right or not. The surest way to get a bad reading is to ride a fast downhill that isn't quite rough enough to cut the power reading out completely. The vibrations mess with the iBike's ability to read inclination, so it thinks you're doing 40mph on a flat rather than a 10% downhill and puts up ridiculous wattage numbers. Before correction, these spikes can really screw up the IF of a ride, as throwing even a couple 800 watt sprints into the middle of a FT workout really skews CP's calculations.

Power response lag: the iBike's response to power changes is damped. It seems to have a half-life of about 1 second, so if you jump from 200 to 400 watts, the display will read 200, 300, 350, 375, 390, 400, taking about 5 seconds before stabilizing on the new value. The same is true with drops in power.

Software issues: before the latest firmware (1.07), a lot of people had problems downloading their data, but that seems to be resolved by and large now. I had some issues, and John Hamann and Richard Wharton were excellent in helping me work them out.

To answer frenchy's question, the iBike App does a linear interpelation of missing data when it downloads the file from the unit. Assuming that the cutout wasn't too long and the before and after readings were reliable, that's usually OK. But if that's not the case ... more fiddling with the raw data in CP.

You can certainly make the iBike look bad by riding a lot of rough downhills. If you saw the two iBike/PT comparison files posted on the wattage list, in one, it did well, but in the second, the rider set out to torture-test the iBike and, sure enough, the NP and IF numbers from the iBike were substantially higher than the PT. But if you looked at the charts from that second ride, you could see that, even there, the iBike was reliable for 90% of the time, then went bonkers for 10%. Since that 10% included things like 5 minutes over 900 watts (on what appeared to be a descent, since PT was showing 0 watts for most of it), the IF was blown way up. In my normal rides, the bad sections are around 1%.

A couple of concerns that I've found which I haven't seen mentioned anywhere:
1) NO LAP BUTTON. The iBike uses "sub-trips" instead, which require you to hold a button down for 2 seconds to start and stop them. Hold a button down on a bouncy handlebar at the end of a VO2Max interval? Nuh-uh! Nor can you time yourself on hill repeats.
2) NO SCREEN THAT SHOWS BOTH POWER AND ELAPSED TIME. How the heck are you supposed to do a timed interval without that? The iBike people have a special-purpose interval tool that's supposed to be coming to the iBike app soon, but it's not there yet, and I'd rather time my own intervals anyway.

Hope this is useful to someone considering the iBike. Reading this forum is what got me interested in power training in the first place, so I thought I'd post something back in thanks.
 
ahaile said:
Hope this is useful to someone considering the iBike. Reading this forum is what got me interested in power training in the first place, so I thought I'd post something back in thanks.
Great post! Thanks! You should post more often.:D
 
Nice review.

Cuts out 10-50% of the time on chip & seal roads? Those are the good roads where I ride.
 
RapDaddyo said:
Great post! Thanks! You should post more often.:D

Thanks :D. Once I've had a couple more weeks to get used to power training, I may have a few questions for you resident experts!
 
mises said:
Nice review.

Cuts out 10-50% of the time on chip & seal roads? Those are the good roads where I ride.

Yeah, I know. I live near the OH/IN border, and it seems like IN is much more fond of chip-seal, so since getting the iBike I've been riding mostly in OH. I'll have to see in a few weeks if this limitation really starts to bother me. It does alright on older chip-seal, where there's been enough car traffic to wear a smooth groove where the cars tires run.
 
ahaile said:
I've got a couple weeks of use on my iBike + CP. Overall, I'm pretty happy, though there are some issues. Here are some answers to some of the questions, based on my experience:
Thanks for the good info. Have you done any group/pack riding or close drafting with the unit. When I first read about the thing, that was the scenario in which I was most interested in seeing the performance.
 
frenchyge said:
Have you done any group/pack riding or close drafting with the unit.

I haven't yet, but there's a good article on nyvelocity.com where a guy compared his PT and iBike numbers while drafting: http://www.nyvelocity.com/content.php?id=889. He found that the iBike underreported watts while drafting by 14% and speculates that the draft happens to be particularly good where the iBike sits on your handlebars -- basically, right behind the lead rider's rear.
 
lanierb said:
According to some users on topica, the worse problem is not the missing sections on bumps, but the fact that the power numbers are wildly off (high) on bumpy roads.


Actually the main issue with ibike and bumpy roads is there are no numbers. This is an acknowledged weak point of the device which I believe the ibike people are still trying to fix and for me, happens only during a very small portion of my rides.
 
ahaile said:
I haven't yet, but there's a good article on nyvelocity.com where a guy compared his PT and iBike numbers while drafting: http://www.nyvelocity.com/content.php?id=889. He found that the iBike underreported watts while drafting by 14% and speculates that the draft happens to be particularly good where the iBike sits on your handlebars -- basically, right behind the lead rider's rear.


I would love to see more reviews out there though. NYvelocity is a great first attempt but really isn't as in-depth or definitive as I would like.
 
The bumpy road issue is tied to speed, at leas in my experience. I've put just under 1100 miles on the iBike. I can ride roads with a wash-board bumpy surface at 15-17 mph with no interruption of readings but on those same roads at 19 mph, there is some interruption. At 22 mph and higher, the interruption occurs even more. On some relatively new chip seal roads, I can get perfect readings at 20 mph, but start to get intermittent dashes at 22 or 23 mph and above.

Otherwise, the unit is an example of perfect consistency for me. I have several routes for my 5 sec, 60 sec, 5 min, 20 min and 60 min tests. I also have my shallow hill ride, and then my 2 steep hill climbs... CP shows my efforts to be very consistent in all of these conditions, with expected minimal decrease after a tough week, and expected minimal increase after a rest day or a couple active rest ride days. Readings jive with my RPE...and all show me to be a 51-year old with more hopes for power than actual power in the bank. But testing shows me to be stronger now than I was in early July, and the fact that I can demonstrate that on CP with my iBike data gives me confidence in the performance and consistency of the iBike. Like all others, though, I can't wait to see more stringent evals against the PT, Polar and SRM...
Bill

jslopez93 said:
I would love to see more reviews out there though. NYvelocity is a great first attempt but really isn't as in-depth or definitive as I would like.