AeroPod, PowerPod and Newton

Hi guys - I've searched the forums and read the manuals but haven't managed to answer these questions:

Why the 5min outdoor acclimitisation?
How important is this and what does it do? The difference between where I store my bike and outdoor temp would rarely be more then 10 degrees C so is this still important?

Block or shelter wind port?
I live in a windy city (Wellington NZ) so there is just about always wind. Should I be physically covering / blocking the wind port during auto wind, or just trying to shelter it from most of the wind? Can do it indoors sometimes, but not always.

Also how do I deal with the auto wind when doing triathlons? If I do the auto wind pre-swim the unit will probably have gone back to sleep by the time I'm ready to get on the bike!

Mounting
My handlebars taper from fat in the centre to narrower as you go out further. The best place to mount the ibike for me is on this taper which means it has a slight tilt to the side. Is this ok? (my tilt cal worked fine first time).

Also the gear cable sits approx 10cm in front of the ibike - is this a problem (affecting wind sensor?)

Replacing batteries
Do I understand correctly that if I need to replace batteries I need to replace BOTH the ibike and wireless mount batteries at the same time?

Is there any warning that cad and spd sensor batteries are getting low, or do they just stop working at some point?

0 watts when riding downhill
When moving fast downhill but still exerting pressure on the pedals my wattage is often reading 0 (or a very low number - sub 60). Does this mean even though I am putting effort in it's not contributing to my speed? In this case I might as well just stop pedalling?

Profiles
Over winter when I wear heavier/more wind resistant gear it's no problem to change the weight settings etc. Should I also be doing a new calibration ride and coast downs to cater for these changes? I guess I'll end up with a number of different profiles for different times of year and riding conditions?

What about small differences like whether I take 1 bottle or 4 on a ride? Over the course of a ride I'll drink 4 bottles, sweat, have toilet stops, refill bottles, etc. How does all of this affect profiles and readings?

Calibration rides and coast downs
MOST of the roads I ride are rough chip seal, although there are some roads (or patches on other roads) of smooth seal. Should I be doing cal rides and coast downs on these rougher chip roads? Should I be changing the Crr manually for this?

Any other advice for ensuring accuracy on these rough roads (and times when it changes from rough to smooth?)

If make any changes that may affect the bike performance (e.g. different tires or tire pressure, race wheels vs training wheels, get a new aero helmet, etc) do i need to do new calibration ride and coast downs?



Sorry, a big barrage there, but I want to get the most out of using my ibike!

Cheers
Gerrard

Bump. Can anyone help me?

So many Q's scare off the best of us.... I'll tackle a few.

gerrard wrote:Why the 5min outdoor acclimitisation?
How important is this and what does it do? The difference between where I store my bike and outdoor temp would rarely be more then 10 degrees C so is this still important?

Since the elevation is done via barometric pressure (and PV=nRT, meaning pressure is directly proportional to temperature), it is best to be acclimated to outdoor temps for the best accuracy.

gerrard wrote:Block or shelter wind port?
I live in a windy city (Wellington NZ) so there is just about always wind. Should I be physically covering / blocking the wind port during auto wind, or just trying to shelter it from most of the wind? Can do it indoors sometimes, but not always.

Get yourself out of the wind or cup your hand over the wind port.... Autowind at power on should only take a minute or so. I think I read it is best to not totally block the port, just keep the wind out.

gerrard wrote:Also how do I deal with the auto wind when doing triathlons? If I do the auto wind pre-swim the unit will probably have gone back to sleep by the time I'm ready to get on the bike!

Good question... I guess you could hit the power button first thing when you enter transition? Maybe have a sock or sandwich bag over unit so there is no wind at power on so it can wind offset while you transition? How important is this data to you? Perhaps someone else can chime in on that.... no triathlons for me.

gerrard wrote:Mounting
My handlebars taper from fat in the centre to narrower as you go out further. The best place to mount the ibike for me is on this taper which means it has a slight tilt to the side. Is this ok? (my tilt cal worked fine first time).

I think the stem mount may be a better option for you, or the new rechargeable mount that mounts on the stem cap (but that tilt may not matter if it is mounted solidly and not too very offset). I have round bars on one bike and molded/aero bars on another. My first bike uses a handlebar mount, I went stem mount for the aero bars. I have the new rechargeable mount on order.

gerrard wrote:Also the gear cable sits approx 10cm in front of the ibike - is this a problem (affecting wind sensor?)

My guess is no, not really, but I am not speaking from experience. Again the stem mount(s) might help here should it be an issue.

gerrard wrote:Replacing batteries
Do I understand correctly that if I need to replace batteries I need to replace BOTH the ibike and wireless mount batteries at the same time?

Is there any warning that cad and spd sensor batteries are getting low, or do they just stop working at some point?

Nah, replace on battery warning in the head unit only (no warnings for the other batteries). Wireless mount less frequently (I ride 5-12 hours per week and I'd guess I am replacing the mount battery 2x per year, but I do have 2 bikes). Speed/cadence I'd guess 1x per year or so unless you see flaky readings.

gerrard wrote:0 watts when riding downhill
When moving fast downhill but still exerting pressure on the pedals my wattage is often reading 0 (or a very low number - sub 60). Does this mean even though I am putting effort in it's not contributing to my speed? In this case I might as well just stop pedalling?

I am due for a new calibration ride (same bars, new bike, have not tweaked my profile) and I see this (so in my case it may be that my profile is whacked). Make sure you have a good tilt and wind offset.

gerrard wrote:Profiles
Over winter when I wear heavier/more wind resistant gear it's no problem to change the weight settings etc. Should I also be doing a new calibration ride and coast downs to cater for these changes? I guess I'll end up with a number of different profiles for different times of year and riding conditions?

Ideally, probably yes. I don't bother.

gerrard wrote:What about small differences like whether I take 1 bottle or 4 on a ride? Over the course of a ride I'll drink 4 bottles, sweat, have toilet stops, refill bottles, etc. How does all of this affect profiles and readings?

I use 2 bottles and typical clothes... see how much your total weight fluctuates. I think you could easily update your weight in the profile, but I think your "sweating" the small stuff (pun intended). I weigh myself every single morning and I fluctuate 2-4 pounds all the time anyhow, I pick my mean weight as my rider weight.

gerrard wrote:Calibration rides and coast downs
MOST of the roads I ride are rough chip seal, although there are some roads (or patches on other roads) of smooth seal. Should I be doing cal rides and coast downs on these rougher chip roads? Should I be changing the Crr manually for this?

My current profiles were derived with coastdowns. My next one with the new mount will likely be a 4 mile out-and-back cal ride only. Comments from John and Coach Boyd seem to indicate the cal ride is so close, coastdowns are not really needed. They are a giant pain to do (in my eyes), and I'd rather be riding, not fidgeting with the iBike if it isn't gaining me much.

That's all I think I can accurately tackle.

Thanks - that's all really useful.

Cheers
Gerrard

"How do I deal with auto wind when doing triathlons?"

I asked the same question last year. This is Velocomps reply (my original post is in the triathlon section of the forum):

"3) Regarding Wind Cal: on race day, take your bike to the transition area, let it stabilize, then do a Cal Wind. This will get the iBike in good shape. Later in the day, during the race, when you get to hop on the bike, click the center button, and the "Auto Wind" will appear. Just click the center button to abort it. Your prior wind calibration will still be preserved and you'll get good results. This, essentially, is the "start riding and press the red button" routine you want!

I agree that the full start-up sequence (including Auto Wind) takes 20 seconds, but clicking the center button twice (once to wake up, once to abort Auto Wind) takes about one second. That would seem to be fast enough..."

Great - thanks.

I think the gain you might get from coast downs is with the crr. But at the same time that may make more sense if you really run soft or wide tires and not anything close to the default value. If you do this once and get a good calibration - use the same crr in the future for any new calibrations.

Tom