New power meter: iBike Pro
Cyclists apply forces to bike pedals in order to overcome the forces resisting forward motion (hill climbs, wind resistance, rolling resistance, acceleration, etc.) Traditional power meters like SRM, Powertap and Ergomo measure the forces applied by the cyclist (direct measuring). The new Ibike Pro
Cyclists apply forces to bike pedals in order to overcome the forces resisting forward motion (hill climbs, wind resistance, rolling resistance, acceleration, etc.) Traditional power meters like SRM, Powertap and Ergomo measure the forces applied by the cyclist (direct measuring). The new is the first power meter that measures the resistive forces working against the cyclist (indirect measuring). The principle is that forces applied by the cyclist is exactly the same as the forces from wind resistance, rolling resistance and gravity. Thus, if you know these factors you can calculate the forces applied by the cyclist. The iBike Pro measure both wind speed, hill gradient and bike speed.
Body position does not affect power output
As you can guess, there are several variables that can possible affect the measuring. One of the biggest problems in my opinion is that the power output will not change if you change body position. That means that data from the rides will reflect the average power output rather than the actual power output.
iBike Pro website FAQ about the body position problem:
“Most riders stay in the same position about 90% of the time or more, so the percentage of the total ride where there is a wattage difference won’t be great. The iBike Pro assumes that the athlete remains in the same riding position, so changes in riding position will not be reflected by changes in the iBike’s wattage readings.”
My opinion about iBike Pro (haven’t tried it yet…)
I think it is a interesting concept, but it is very difficult for me to understand why they measure power indirectly. That doesn’t make sense to me. I am not sure that this product can be used to seious wattage training, but I would really like to try one to see how it performs. There are some good things that could make iBike Pro to a competitor for the other power metres: It weights only 60g and costs 399$, which is nothing compared to the more expensive and heavier products on the market.
Like this blog? Subscribe to Training4cyclists.com's RSS Feed!
John Hamann said,
October 27, 2006 @ 6:19 pm
Here are some links from independent reviewers who have made direct comparisons between the iBike and conventional power meters.
http://www.cyclingforums.com/showthread.php?p=3054408#post3054408
http://www.thresholdpower.com/images/ibike_SRM_comparison.gif
http://www.thresholdpower.com/images/ibike_SRM_comparison_2.gif
http://forums.roadbikereview.com/showthread.php?p=815991#post815991
http://www.djconnel.com/cycling/SRM_vs_iBike.pdf
Jesper Therkildsen said,
October 29, 2006 @ 5:44 pm
Thanks for showing these threads.
It is very difficult to review these power meters only by viewing these curves. All curves with power files from Polar, SRM, Ergomo, Powertap, iBike Pro etc. look similar on distance. E.g. when you use a Polar power meter your average watt might likely be the same as if you used a more expensive power meter. But you will probably not notice how you are performing during intervals because it is not reliable enough. The Polar is not sensitive enough for accelarations, which make it difficult to use it during intervals for pacing strategy. I don’t know how precisely iBike Pro react to accelerations/change in speed. I think that is much more interesting thing to know than how it performs on average during a long ride. So if iBike Pro send me a power meter there will be a comprehensive review of it during the winter.
iBike Owner said,
December 2, 2006 @ 8:45 am
Why is everyone beating around the bush about this product. It obviously sucks! I have an iBike and a Powertap and I have been comparing them side by side and here are the conclusions:
The iBike is NOT useful for training it is strictly a gadget and here is why:
The iBike is not at all accurate real time. MOST OF THE TIME the iBike is significantly (often 50-100 Watts) high or low. If you have ever (seriously) trained to power then you know that just a few watts (let’s say 10% of your max) high or low makes a HUGE difference when you are trying to hold a set wattage for a while; and with this much error, you will have a horrible workout with the iBike. Sure, the marketing folks at iBike like to point to average watts and say that it is accurate but this is not relevant to real time training on the bike. The iBike is USELESS as a real time wattage training tool. There are also several other serious problems for example:
1) What about WINTER time ??? YOU CAN’T USE THE iBIKE INDOORS ! You will have to buy 2 power meters anyhow so what good is it ?
2) The iBike is completely inaccurate on the slightest rough road.
3) Turns. The iBike is flat out wrong when going through turns.
4) Drafting. Yes, the marketing team at iBike want you to think that it is more accurate when in bigger packs. BS ! I have tried it. It is WRONG WRONG WRONG in the draft.
So here is the conclusion, If:
1) You just like gadgets and don’t care if they really work.
2) You never turn.
3) You never ride in the draft.
4) You don’t mind a significantly wrong watts readout while you are training.
5) You are a sucker and believe all of the BS that iBike and those that stand to benefit from iBike sales tell you.
Then go buy an iBike — There are plenty of them for sale on eBay from the people who have gotten suckered into buying one and can’t get a refund.
Otherwise, if you are smart, go buy a PowerTap, Ergomo etc…
iBike Owner said,
December 2, 2006 @ 9:20 am
Just for clarification, when I said “let’s say 10% of your max”, I meant 10% of your max hour of power, which is probably 25-50 Watts unless you are Lance Armstrong prior to 2006 (Sorry Lance!).
Another iBike Owner said,
December 18, 2006 @ 4:02 pm
IBike Owner, a Google search of reviews for the iBike show that you’ve been on several of these forums and championing the same cause. So far, you’re a voice of one.
I just started using the iBike. For this rec rider who is only interested in training to be as fast or faster than the other rec riders in the club, the iBike is priced just right and is more than good enough.
So, why aren’t you slamming Dr. Coggan and Mr. Allen for support a “useless” device in their CyclingPeaks software? Don’t you think that they are able to see the uselessness of the device, too? Or, maybe they know something you don’t know.
David Regula said,
February 20, 2007 @ 5:38 am
The ibike is a tool. It might not be the right tool for everyone but it is still a very useful tool. It provides information that other devices do not such as wind, altitude, aero/drivetrain friction and grade. It costs significantly less than other devices. There appears to be an on going debate about its watt accuracy, while I have seen an occasional power spike after hitting potholes I find that the ibike gives me the same readings as my Computrainer. Some ibike riders have used the ibike to improve their aero friction.
There are alot of new tools available to cyclist, iBike will be one of the more popular choices. The product works, and the customer service is excellent.
There are a few people trash talking the iBike, my experience does not support their claims, since their claims are so exaggerated I can only conclude that they feel threatened by the iBike.