2 Bikes, 1 Profile

[tbarczak]

So I have a road bike setup with a stem mount, wireless iPro. It's been working great. I just bought a new road bike. Same size, very similar weight. Wheels and configuration are all identical to the bike I've had. Just a new frame. Position is the same on the bike as well.

So the question is, do I really need to change my profile much between these two bikes? If I do the Tilt Calibration when I switch the unit between the two bikes, assuming I position the iBike in the exact same (as close as possible) position on both stems, my thinking is that the profile numbers should be about the same. At least close enough...

Thoughts?

[lorduintah]

I would think a cal ride will tell you if anything else is needed.

The iBike will get a different wind scaling - you just cannot duplicate the exact potion - same result with the tilt correction - both of these you get from the cal ride. Then you could at the very least use the other values in the profile from the previous bike - for a start. Or do the whole cal ride and coast downs and get a comparison - and post the similarity or delta to the forum!

Tom

[jparker]

I've also got two bikes that are set up with the same measurements (both Specialized Tarmacs but different year models) and the wind scaling and aero are almost the same but with the two profiles avalible on the Bike I think you should do the calibration and coast downs and make it as accurate as possible especially if you use one for poor weather/training and one for good weather/racing which usually involve different clothing which will effect your numbers as you know. You should be able to cross reference your current numbers(winter and summer etc...)with the new calibration and coast downs to determine how close they actually are and save them all and keep 4 profiles, 2 for each bike, in your software and depending on which bike and what time of year it is etc... just download which profile you need, check your tilt and go.

[tbarczak]

Your points are well taken about re-doing the cal ride. I actually did that yesterday using a linked powertap and the what it said was that these are the new values:
Aero: 0.353
Wind Scaling: 1.101
CdA: 0.320

Versus my existing profile:
Aero: 0.289
WS: 0.877
Cda: 0.330


In any case, did a very standard 4.5hr ride today with it using the old profile (new bike). The numbers are on the low side, but not entirely bad. I actually know a segment of the ride in terms of what the watts should be so I was hoping to manually tweak the file to fix it. In short the file is about 500kJ low.

But I am impressed at how close it is relatively speaking.

So two questions. First, how do I manually change the wind scaling value of a file? And do the differences shown look reasonable for the theory of two very similar bikes and setups?

[jparker]

To change your windscaling, aero...etc. and apply it to that ride you'll need to go in tools and use the first selection which is select profile after ride and it will give you the option to choose between the profiles you've set up in your profile tab. If you don't have the profile numbers that you want to change it to you can go to a previous ride, hit the profile tab and then use the Extract from ride file and it will pull the profile numbers in and then you can use the edit profile tab labeled Advanced and play with numbers and tweak them to compare to your exsisting numbers. This way you can delete this file if needed and not have worry about messing with any of your current (Good) profiles that already exsist and it's numbers or if you get the numbers to a point where they work then you can just keep the new profile you've tweaked, download it into the iBike for your new bikes profile. That's what I did but my numbers were so close I really could have gone with one profile but like I said why when the computer allows for 2. Hope this helped - I'm not the best at explaning how I went though my process but I gave it a shot.

[tbarczak]

Thanks, that approach worked well.