Hy Folks.
i´m new in the iBike world. Till now i only trained with a Powertap SL+ hub on my Road Bike and im pretty exited with it. About a few weeks ago i bought a new TT bike for competition.
Cause the SL+ hub is mounted on my training wheel set i was looking for "cheap" powermeter solution for my TT bike and i ended up with a used iBike Pro Gen III with various mounts, RWS
sensor, GT Firmware update and so on. Was a good deal on Ebay. Till today (in case of to much work und the bad weather in my region) i was not able to test the iBike on my TT bike. So i
have no experience with it.
A few days ago i took a look on the iBike Hompage and saw the announcement of the new iBike Newton. If i knew that earlier i would go for the iBike Newton. Now i´m wondering if i
should use the option of the early preorder and Trade in programm.
I manly use the TT bike for competition and the long training rides (i´m training for my first Ironman). The most time in training i spend on my roadbike (clip on aerobars and so on...).
And therefor i have my powertap SL+ hub. In competition and the long training rides and use the powermeter for pacing. Does anyone have a commendation for me. Is my iBike Pro Gen III
"good enough" for my desired use or should i spend the extra money for the trade in programm?
Any opinions?
regards.
iBike Newton or iBike Gen III
Re: iBike Newton or iBike Gen III
Well, I won't speak badly about any of our children 
but most certainly the Newton has a ton of improvements over any prior generation iBike.
but most certainly the Newton has a ton of improvements over any prior generation iBike.John Hamann
Re: iBike Newton or iBike Gen III
Hi Schmott,
I won't speak badly of any of the iBikes either but having had every version since the Gen I, I can say every upgrade was well worth it and the product has come a long way.
I have had the Newton+ for six days now and have had several rides as well as tinkering with extra cal rides and optional coastdowns. My opinion is that the Newton is now a great power meter. I say this having only owned iBikes for power meters.
If you do it I think you won't regret it. The best improvements are new sensors and the battery life. I ran an external battery rigged per forum tips until the latest Gen III wireless mount came out with the rechargeable battery boost which mostly solved the Gen III battery issues. But the Gen IV Newton is welcome relief from the battery concerns period!
The power and wind readings are noticibly more stable. My coastdowns have been far more consistant which speaks volumes for the improved sensors.
I hope and expect that the affect of large temperature changes on the wind sensor to be past history as well. Although the post processing of the iBike software fixed the issue very well after the ride, it was an annoyance during those rides.
Just my 2 cents worth!
Russ
I won't speak badly of any of the iBikes either but having had every version since the Gen I, I can say every upgrade was well worth it and the product has come a long way.
I have had the Newton+ for six days now and have had several rides as well as tinkering with extra cal rides and optional coastdowns. My opinion is that the Newton is now a great power meter. I say this having only owned iBikes for power meters.
If you do it I think you won't regret it. The best improvements are new sensors and the battery life. I ran an external battery rigged per forum tips until the latest Gen III wireless mount came out with the rechargeable battery boost which mostly solved the Gen III battery issues. But the Gen IV Newton is welcome relief from the battery concerns period!
The power and wind readings are noticibly more stable. My coastdowns have been far more consistant which speaks volumes for the improved sensors.
I hope and expect that the affect of large temperature changes on the wind sensor to be past history as well. Although the post processing of the iBike software fixed the issue very well after the ride, it was an annoyance during those rides.
Just my 2 cents worth!
Russ
Re: iBike Newton or iBike Gen III
How was it fixed? Looking at the net wind on the ride sort of works, but not very well.Russ wrote:I hope and expect that the affect of large temperature changes on the wind sensor to be past history as well. Although the post processing of the iBike software fixed the issue very well after the ride, it was an annoyance during those rides.
Have the sensors really been improved vs the Gen3? I see that the wind port has been improved but I wonder... is the tilt less effected by chipseal and the barometric altimeter more accurate? I actually don't know if it's possible to make the barometric sensor more accurate, but I've noticed ~5% scatter on the elevation change for long climbs. Could be atmospheric randomness I guess.
Re: iBike Newton or iBike Gen III
I have both a PT and an iBike Gen3. I much prefer the PT on the TT bike. For one, I'm nearly always racing when I ride it, and the data is more consistent and repeatable than the iBike. Cross winds, high speeds, bumps or rough pavement, all mess up the real time data on the iBike. It can all be cleaned up decently after the fact, but I think you will be frustrated if you are wanting accurate real time info. On the road bike I don't mind if it is "off" sometimes during the ride... plus it is lighter and I can swap wheels.Schmott wrote:i´m new in the iBike world. Till now i only trained with a Powertap SL+ hub on my Road Bike and im pretty exited with it. About a few weeks ago i bought a new TT bike for competition.
Cause the SL+ hub is mounted on my training wheel set i was looking for "cheap" powermeter solution for my TT bike and i ended up with a used iBike Pro Gen III with various mounts, RWS
sensor, GT Firmware update and so on. Was a good deal on Ebay. Till today (in case of to much work und the bad weather in my region) i was not able to test the iBike on my TT bike. So i
have no experience with it.
BTW... you can put a plastic disc cover on your PT wheel and use it for TTs.
Re: iBike Newton or iBike Gen III
Schmott,
"How was it fixed? Looking at the net wind on the ride sort of works, but not very well."
Yes the air sensors are temperature compensated in hardware with the Newton and the Dash, per John's posts in this forum. I am not sure about the improvements in the accelerometers but I think he said all sensors are much more accurate.
Again, I have never had a PT to compare with but I can compare the (still short) experience of the Newton with the Gen III and prior.
I expect atmospheric pressure changes will still rule elevation reports in the iBike since the elevation and slope are corrected to the pressure, I think starting with Gen III if I recall correctly. So that can be corrected after the fact but you have to live with that during the ride. I do not see that drastically affecting anything other than the climbing total. btw My Garmin gps's with atmospheric pressure sensor correction do noticeably worse than the iBike for elevation data for what that is worth
I cannot explain the apparently improved stability of the readings. It is my observation to be the case. Perhaps John would care to lift the vale a bit in this area if there are indeed technical details to brag about (hint hint)
Regards,
Russ
"How was it fixed? Looking at the net wind on the ride sort of works, but not very well."
Yes the air sensors are temperature compensated in hardware with the Newton and the Dash, per John's posts in this forum. I am not sure about the improvements in the accelerometers but I think he said all sensors are much more accurate.
Again, I have never had a PT to compare with but I can compare the (still short) experience of the Newton with the Gen III and prior.
I expect atmospheric pressure changes will still rule elevation reports in the iBike since the elevation and slope are corrected to the pressure, I think starting with Gen III if I recall correctly. So that can be corrected after the fact but you have to live with that during the ride. I do not see that drastically affecting anything other than the climbing total. btw My Garmin gps's with atmospheric pressure sensor correction do noticeably worse than the iBike for elevation data for what that is worth
I cannot explain the apparently improved stability of the readings. It is my observation to be the case. Perhaps John would care to lift the vale a bit in this area if there are indeed technical details to brag about (hint hint)
Regards,
Russ
Re: iBike Newton or iBike Gen III
The original iBike was designed in 2004-2005, with analog sensors. We kept this same architecture through the Gen III.
The Newton was designed in 2011-2012, with digital sensors and latest-generation microprocessors. The electronics is a complete redesign.
Of particular note, all sensors are MUCH better than their predecessors, in terms of sensitivity, accuracy, noise, and temperature stability. We have added considerable cost to the circuit board in order to use these sensors.
The cross-fin wind port design is important, too, because it does a much better job of dealing with cross-wind situations.
Finally, the wind port shape has changed, too, so that RWS usage is much more user-friendly.
All of the early reports on the Newton I have seen have been quite favorable, and with good reason.
There's no doubt that (with your help) we will find firmware tweaks that will optimize even more the performance of the Newton.
The Newton was designed in 2011-2012, with digital sensors and latest-generation microprocessors. The electronics is a complete redesign.
Of particular note, all sensors are MUCH better than their predecessors, in terms of sensitivity, accuracy, noise, and temperature stability. We have added considerable cost to the circuit board in order to use these sensors.
The cross-fin wind port design is important, too, because it does a much better job of dealing with cross-wind situations.
Finally, the wind port shape has changed, too, so that RWS usage is much more user-friendly.
All of the early reports on the Newton I have seen have been quite favorable, and with good reason.
There's no doubt that (with your help) we will find firmware tweaks that will optimize even more the performance of the Newton.
John Hamann
Re: iBike Newton or iBike Gen III
Thanks for the info John! Good to know.
I wondered if you could provide any insight regarding the altimeter. The altitude variations I've seen are not due to the pressure changing during the ride, since the altitude when I come back down will be about the same as it was before. If I set the altitude at the bottom of the climb, the altitude change to the top will vary ~5% (or in other words a ~5% variation in slope and power) . This is going from about 7800ft to 10000ft, so ~100ft of scatter in the elevation at the top.
Do you know what would cause it? The sensor appears to be much more precise than this. I wonder if it is due to a random variations in atmospheric pressure vs altitude... or maybe it *could* be accounted for with more info... like an input of the current sea level pressure?
I wondered if you could provide any insight regarding the altimeter. The altitude variations I've seen are not due to the pressure changing during the ride, since the altitude when I come back down will be about the same as it was before. If I set the altitude at the bottom of the climb, the altitude change to the top will vary ~5% (or in other words a ~5% variation in slope and power) . This is going from about 7800ft to 10000ft, so ~100ft of scatter in the elevation at the top.
Do you know what would cause it? The sensor appears to be much more precise than this. I wonder if it is due to a random variations in atmospheric pressure vs altitude... or maybe it *could* be accounted for with more info... like an input of the current sea level pressure?
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lorduintah
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Re: iBike Newton or iBike Gen III
Wind is the result of pressure diffentials - gradients - at the same elevation --- an altimeter does not know about wind - just pressure - so any breeze/gust will look like an elevation change.
http://upload.wikimedia.org/wikipedia/c ... titude.png
Things like humidity can also have an impact.
What I do not know is how much sensitivity and response time the altimeter has in this application (and resolution.)
Tom
A graph of pressure vs. altitude -The pressure gradient is the change in barometric pressure over a distance. Big changes within shorter distances equals high wind speeds, while environments that exhibit less change in pressure with distance generate lower or non-existent winds. This is because higher-pressure air always moves toward air of lower pressure in an attempt to gain balance within the atmosphere. Steeper gradients result in a stronger push.
Read more: The Relationship Between Pressure Gradient & Wind Speed | eHow.com http://www.ehow.com/about_5052107_relat ... z1yAcMqFiP
http://upload.wikimedia.org/wikipedia/c ... titude.png
Things like humidity can also have an impact.
What I do not know is how much sensitivity and response time the altimeter has in this application (and resolution.)
Tom
Re: iBike Newton or iBike Gen III
I assume you are talking about the Gen III baro sensor. I have seen extremely stable performance out of the Newton baro sensor.rruff wrote:Thanks for the info John! Good to know.
I wondered if you could provide any insight regarding the altimeter. The altitude variations I've seen are not due to the pressure changing during the ride, since the altitude when I come back down will be about the same as it was before. If I set the altitude at the bottom of the climb, the altitude change to the top will vary ~5% (or in other words a ~5% variation in slope and power) . This is going from about 7800ft to 10000ft, so ~100ft of scatter in the elevation at the top.
Do you know what would cause it? The sensor appears to be much more precise than this. I wonder if it is due to a random variations in atmospheric pressure vs altitude... or maybe it *could* be accounted for with more info... like an input of the current sea level pressure?
John Hamann
Re: iBike Newton or iBike Gen III
The pressure sensor responds very quickly and appears to be precise... it needs to be to measure relative wind speed. I'll have to investigate this more to see if barometric altitude is effected enough by wind to cause the variation I see. I was hoping that there was a way to get more accurate data using the iBike sensors, but it may already be as good as it can get.
John... yes, it's the Gen3.
John... yes, it's the Gen3.
Re: iBike Newton or iBike Gen III
Wind and baro sensors in the Newton are of much more recent design, and are significantly better.rruff wrote:The pressure sensor responds very quickly and appears to be precise... it needs to be to measure relative wind speed. I'll have to investigate this more to see if barometric altitude is effected enough by wind to cause the variation I see. I was hoping that there was a way to get more accurate data using the iBike sensors, but it may already be as good as it can get.
John... yes, it's the Gen3.
John Hamann
Re: iBike Newton or iBike Gen III
Best site I found discussing baro altitude measurements. http://www.hills-database.co.uk/altim.html
If I understand correctly, it looks like the uncertainty concerning the temperature of the air column is the most likely cause of errors, if the barometric drift is small... this is even if the sensor is perfect in its accuracy. Whenever I do this climb the humidity is usually low and the temperature between 65-75 at the base, so not a huge amount of variation typically.
So I wonder... what is the algorithm the iBike uses to compute altitude? Is it is good as it could be? Is the temperature measurement even used?
If I understand correctly, it looks like the uncertainty concerning the temperature of the air column is the most likely cause of errors, if the barometric drift is small... this is even if the sensor is perfect in its accuracy. Whenever I do this climb the humidity is usually low and the temperature between 65-75 at the base, so not a huge amount of variation typically.
So I wonder... what is the algorithm the iBike uses to compute altitude? Is it is good as it could be? Is the temperature measurement even used?