ibike on e-motion rollers

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NCH1
Posts: 100
Joined: Mon Dec 28, 2009 12:33 am
Location: Sydney, Australia

ibike on e-motion rollers

Post by NCH1 »

I have a set of e-motion rollers on order and I was wondering what sort of experiences people were having training with power (with the ibike) on them. I have read several post here about tyre pressure, rider weight etc affecting the accuracy of the speed/power curve compared to riding outdoors.

I have noticed too that when editing the roller setting for weight in the ibike software, this differs somewhat from the 2008 excel spreadsheet calculation provided by the insideride calculator. I noticed that for my weight and on resistance level 3 at 20 mph I can achieve 293 watts approx. In the ibike calculation for the same speed and weight I can achieve 283 watts. Therefore is ibike's calculation more recent and based on speed/power tests conducted by ibike?

Nik
MdC
Posts: 45
Joined: Mon Apr 28, 2008 12:08 am

Re: ibike on e-motion rollers

Post by MdC »

I cannot comment on the e-motions per se, but I will say the resistance varies considerably with ambient tempreature. For example, I get around 100 watts more according to the curve compared to winter for the same speed, weight, pressure. Perhaps it's just my rollers but I would not be surprised if you saw the a difference also. It doesn't mean you can't get a benefit from them. Rollers are great, you just might have to go by heart rate and feel.
You'll soon figure out what you can do.
smhagger707
Posts: 38
Joined: Thu May 27, 2010 1:37 pm

Re: ibike on e-motion rollers

Post by smhagger707 »

NCH1 wrote:I have a set of e-motion rollers on order and I was wondering what sort of experiences people were having training with power (with the ibike) on them. I have read several post here about tyre pressure, rider weight etc affecting the accuracy of the speed/power curve compared to riding outdoors.

I have noticed too that when editing the roller setting for weight in the ibike software, this differs somewhat from the 2008 excel spreadsheet calculation provided by the insideride calculator. I noticed that for my weight and on resistance level 3 at 20 mph I can achieve 293 watts approx. In the ibike calculation for the same speed and weight I can achieve 283 watts. Therefore is ibike's calculation more recent and based on speed/power tests conducted by ibike?

Nik
I have a iPro with the trainer firmware and set of e-motion rollers. I haven't yet begun riding much on the rollers as the snow hasn't started falling quite yet where I live. I will be starting to ride the rollers more in the next week or so and will be sure to check how the power curve programmed into the iBike compares to the spreadsheet's prediction. In case you're interested, I did have someone with a PowerTap compared their power readings against the e-motion spreadsheet and report back on the correlation. This information can be found at the following link: http://www.bikeforums.net/archive/index ... 13294.html . Hope this information is useful. I'll keep in touch with what I find as I start riding the rollers more...
NCH1
Posts: 100
Joined: Mon Dec 28, 2009 12:33 am
Location: Sydney, Australia

Re: ibike on e-motion rollers

Post by NCH1 »

Thanks very much for your response, mate. These figures will be very useful. Having placed the order for the unit, doubt was starting to creep into my mind as to the rollers speed/curve accuracy and whether it was a wise choice. Please do keep us posted on any other information you obtain.

Thanks again.

Nik
NCH1
Posts: 100
Joined: Mon Dec 28, 2009 12:33 am
Location: Sydney, Australia

Re: ibike on e-motion rollers

Post by NCH1 »

Plugging in the numbers from the link that smhagger707 posted, it looks like for resistance level 1 the ibike's calculation of the speed/power curve is almost spot on with the numbers experienced with a powertap. If anyone has done any speed/power testing on resistance levels 2 and 3 and could post any data, it would be much appreciated.

Why the need?. I'm hoping to use the rollers for FTP intervals. There are just to many traffic lights where I live and these constant pauses of greater than 30 seconds reduce the effect of the interval work outs.

Nik
smhagger707
Posts: 38
Joined: Thu May 27, 2010 1:37 pm

Re: ibike on e-motion rollers

Post by smhagger707 »

I'm back-sorry for taking so long to post the results. The weather has been 'good enough' to do my easy riding outdoors and the end of Oct thru this past week has mostly been taking time off from a long year (for me) of riding. Today's inclement weather kept me inside on the rollers so I decided to get the data requested at the end of my ride tonight. Thus, you'll have to scroll to the end of the attached iBike file to get the raw data as the first 46:30 is from a 'fat burning level 1' workout (from the iSport booklet).

Attached is the data file from the ride along with the screen shot of the comparison matrix showing my numbers on the left 3 columns and the reference linked above (PT comparison) in the rightmost 3 columns. A few notes: my iPro weight was set at 158 lbs, so I used that weight in the e-motion calculator spreadsheet to see how the iPro values compared. My actual measured weight halfway through the ride (where my HR drops down) was 157.4 as I walked off the rollers (bike, bottles, gloves, etc). Body weight at the beginning of the ride (naked) was 134.2, at the end it was 134.0. Not sure if it matters or not, but my tire pressure was 85 psi Front, 95 psi Rear. Mag setting = 1 for all data I collected tonight (can gather more data in the coming weeks if desired).

Conclusion: the curve in the iPro really follows the calculated value very closely.

Questions, comments? Did I leave anything out?
Attachments
iPro to E-motion power comparison.jpg
iPro to E-motion power comparison.jpg (236.63 KiB) Viewed 7114 times
iPro__Trainer_Ride_11_24_2010_1728_12_Miles.csv
(696.64 KiB) Downloaded 360 times
NCH1
Posts: 100
Joined: Mon Dec 28, 2009 12:33 am
Location: Sydney, Australia

Re: ibike on e-motion rollers

Post by NCH1 »

Thanks very much mate for taking the time to put that together. The figures do seem to correlate quite closely.

I'm more of Thor Hushovd's type build: 84 kg, so It looks like at my weight +bike weight of 7kg I can approximately attain the required 300 watts at about 21.9 mph on resistance level 1, so that s good to know.

Are you using trainer specific tyres or just slick road tyres on the e-motion rollers?.

Nik
smhagger707
Posts: 38
Joined: Thu May 27, 2010 1:37 pm

Re: ibike on e-motion rollers

Post by smhagger707 »

NCH1 wrote:
Are you using trainer specific tyres or just slick road tyres on the e-motion rollers?.

Nik
I was riding Conti GP4000s tires. I don't plan to continue to ride those on my rollers as I don't wish to chew them up indoors. I'll probably put my nearly dead Conti Race tires back on and squeeze the last bit of life out of them on the rollers, the switch to something else...
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