My Gen 3 is back with Velocomp for repair as it suffered from the cracked gasket issue a few others have noticed presumably with the tight fit on the USB mount.
So I intend to use my old Gen 1 unit (rel 1.18) on my wireless mounts.
I have imported my Gen 3 profile (fric and aero etc) - so this should be good to go as a stop gap should it not, until my repaired gen 3 comes back? Aside from some of the features like the intervals, absolute wind etc, if I recall correctly the only downside should be the lower stability on rough roads?
Anyone think of any other issues, it is important to me as I am conducting a MAP test over the weekend ( starting at 150 watts and increasing by 25 watts each minute until I can not go any further). I don't want anything to invalidate the test or make the numbers unrepeatable on my Gen 3. As the business end of the test will be on a hill and speed will be less than 20 mph, rough road should not spike my output.
Gen 1 unit
Re: Gen 1 unit
I had a similar problem and fell back to a GenII unit.
In theory you should be able to load the profile and go, but in reality I found that didn't work for me. I just did a new cal ride/coast downs.
Things like wind scaling may be different between the units and of course gen I doesn't have tilt correction.
In theory you should be able to load the profile and go, but in reality I found that didn't work for me. I just did a new cal ride/coast downs.
Things like wind scaling may be different between the units and of course gen I doesn't have tilt correction.
Re: Gen 1 unit
Wellmt - thanks for the comments. I wzs hoping to avoid doing coastdowns again and a cal ride.
How long were you without your Gen 3?
How long were you without your Gen 3?
Re: Gen 1 unit
About 11 days in total I think. That was to the UK. Service from Velocomp is excellent.
Re: Gen 1 unit
Benlane,
I would give a handbuilt profile a try (if you have time) because the gen3 probably has given you a good (or at least better) set of values for CdA and Crr.
So I would copy my old gen 1 profile (if you don't have one, do a short ride with your gen 1 and then extract the profile from the ride file.
Then insert the CdA and Crr values, use the tilt (I think) from the gen3 as that should be good and tweek the fric, if necessary, to register the Crr value from gen3. Also use your old wind scaling from the gen1 and tweek the aero value to achieve the CdA (or do the math) for gen3 CdA * wind scale to get aero.
Try it out for reasonability on a known course, compare to prior gen3 ride, if possible using software correction in ibike3 software first.
If that isn't good enough then do the new profile.
Just my speculations, hope may help.
Russ
I would give a handbuilt profile a try (if you have time) because the gen3 probably has given you a good (or at least better) set of values for CdA and Crr.
So I would copy my old gen 1 profile (if you don't have one, do a short ride with your gen 1 and then extract the profile from the ride file.
Then insert the CdA and Crr values, use the tilt (I think) from the gen3 as that should be good and tweek the fric, if necessary, to register the Crr value from gen3. Also use your old wind scaling from the gen1 and tweek the aero value to achieve the CdA (or do the math) for gen3 CdA * wind scale to get aero.
Try it out for reasonability on a known course, compare to prior gen3 ride, if possible using software correction in ibike3 software first.
If that isn't good enough then do the new profile.
Just my speculations, hope may help.
Russ
Re: Gen 1 unit
Russ thqat's what I am trying to do, I dod a couple of coast downs and a cal ride this morning. Intend to take the new windscale number and then tweak aero value to get my Gen 3 cda. I did get a new riding tilt from todays cal ride which is hugle different to my Gen3 value (gen 3 -0.3, todays gen 1 +0.8)
So I was unsure what to do, as if I take the cal ride value of +0.8 then I can't really manipulate fric to get to my CRR of 0.0057.
I am in the UK like Wellmt and i find like he does that I get CRR values way outside the 'accepted' range e.g. my coastdown and cal ride on gen1 setup today yielded a crr of 0.0200.
By the time I have it cracked my gen 3 will be back
So I was unsure what to do, as if I take the cal ride value of +0.8 then I can't really manipulate fric to get to my CRR of 0.0057.
I am in the UK like Wellmt and i find like he does that I get CRR values way outside the 'accepted' range e.g. my coastdown and cal ride on gen1 setup today yielded a crr of 0.0200.
By the time I have it cracked my gen 3 will be back
Re: Gen 1 unit
Benlane do you mean a CRR of .0200 as you posted, or .0020? I tended to get .0020 (the normal range is usually .0040 to 0090).
I've never seen a tilt like that before. Everytime I've had a big positive tilt it's because the tilt is wrong, but I'm using a stem mount. How about you?
By the way, in the end with GenIII V4 firmware, I've found the key (thanks to John Hamann's guidance) to a better CRR is to do a 4 mile cal ride (not 2 mile) and not to not use estimated CRR when doing numerous coast downs. I know that doesn't help you today though
I've never seen a tilt like that before. Everytime I've had a big positive tilt it's because the tilt is wrong, but I'm using a stem mount. How about you?
By the way, in the end with GenIII V4 firmware, I've found the key (thanks to John Hamann's guidance) to a better CRR is to do a 4 mile cal ride (not 2 mile) and not to not use estimated CRR when doing numerous coast downs. I know that doesn't help you today though
Re: Gen 1 unit
Wellmt - definatley as posted, i haven't missed a zero after the decimal point. I think it must be because of that big 0.8% riding tilt figure.
Every time i have done the calibration process whether months back on Gen 1 or recently on gen3 I never end up with a CRR within the 'norm' range.
I use a wireless stem mount.
it does my head in.
Every time i have done the calibration process whether months back on Gen 1 or recently on gen3 I never end up with a CRR within the 'norm' range.
I use a wireless stem mount.
it does my head in.
Re: Gen 1 unit
I hear you. I was there a couple of weeks back too.
I've now got hold of a Powertap and can actually see that the iBike can really work and the numbers obtained can be spot on.
So it's worth persevering to get a good profile..Be super careful with the tilt calibration (especially on the older units as these don't have the same 3 direction checking as GenIII), do the cal ride and coast down on as calm a day as possible and do multiple coast downs - I do 6-12 usually. One or two just isn't enough data to get a good average.
I've now got hold of a Powertap and can actually see that the iBike can really work and the numbers obtained can be spot on.
So it's worth persevering to get a good profile..Be super careful with the tilt calibration (especially on the older units as these don't have the same 3 direction checking as GenIII), do the cal ride and coast down on as calm a day as possible and do multiple coast downs - I do 6-12 usually. One or two just isn't enough data to get a good average.
Last edited by wellmt on Mon Jul 20, 2009 8:28 am, edited 1 time in total.
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lorduintah
- Posts: 642
- Joined: Fri Jan 11, 2008 9:37 am
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Re: Gen 1 unit
The positive tilt that I have run across was a ever so slightly loose mount. You do the coast downs and also cal ride - hit the center button and end up with a slight change in the tilt. Slight may not seem like much but these things are very sensitive to exactly that.
Check your tilt after doing the CDs and Cal Ride - the usual take a reading in one direction, do a 180 in the same position and take another - the change should just be a sign change of the same value. Also, doing this in the same place before and after your rides - you should get the same values.
Tom
Check your tilt after doing the CDs and Cal Ride - the usual take a reading in one direction, do a 180 in the same position and take another - the change should just be a sign change of the same value. Also, doing this in the same place before and after your rides - you should get the same values.
Tom