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Agreed on most of your points, except that altitude precision is lower on average than lat/long. Given the triangulation angles between satellites, and the fact that you can't obviously detect signals from satellites that are below you through the earth (to have a good altitude angle with the ones that are above you), the precision is around 1.5 times worse for altitude.

You are right about all the problems for barometric altitude estimation, it needs calibration from known points at the beginning of a trace, although a constant offset is not a problem for cycling, but also changing meteorologic conditions during a ride can offset altitude (you can see it if you do a closed circuit and the final measured altitude differs from the initial one). I wasn't aware of the the temperature issue though, I guess that could be a real problem given the heat most of these phones generate.

I, for one, welcome the tech look that is slowly rising again for skate shoes... Please bring back the Koston IIs...

You're not going to get it as accurate as 1m. Garmin quote the accuracy of an 800, when properly calibrated, as a range of accuracy of +/- 10ft.

So that's a 20ft range of accuracy, or 6 metres. I'm fairly sure the barometer in a Garmin, being specifically designed for the task and made by a company who have a lot of experience in aviation will be more accurate than the barometer in a phone...

Sorry I didn't get the numbers right, they were just orders of magnitude. GPS altitude is more like +/- 25 m, i.e. 50 m range compared to 6 meters for the Garmin according to you. I even think it is worse than that for GPS, given that Strava prefers to map altitude from GPS lat/long coordinates using 90 m precision altitude maps rather than use the GPS altitude. So there is a 10X factor to be gained by using barometer-based altitude compared to GPS altitude.

As regards the precision of smart phones barometers, it seems to rely mostly on good software that properly calibrate it, for example using good reference GPS lat/long points or successive readings at the same point, as the Garmin do. As for pressure sensors themselves I don't think the hardware quality is vastly different.

I was wondering,
Does any of you know an android GPS logging app (preferably targeted for cyclists) that would use the built-in pressure sensor (barometer) present in the Nexus 4 for measuring the altitude with a good precision (1m instead of >10m with GPS)? I've found an app called ipBike, but it doesn't seem to leverage the barometer on the Nexus 4 (other pressure sensor equipped phones like Galaxy Nexus or Galaxy S3 are listed as compatible though).

The SONY Xperia i1 as I've said before, will be my next phone. Here's why:

http://www.knowyourmobile.com/sony/sony-xperia-honami-i1/20875/sony-xperia-honami-i1-destroys-htc-one-and-galaxy-s4-benchmarks

working link

too bad I can only give +zero rep.

how does it compare to a Brompton?

Indeed I have, hence the question. I was wondering why (is it standard for rear/front, 650/700, clinchers vs tubulars, or different generations?) As Gaston has seen more 4-spokes than I'll ever I thought he'd tell.

There are different valve positions on rear and front corimas? Is the valve hidden by the black stuff on the front wheel ?

We do it here, disguising phone masts as trees.

http://waynesword.palomar.edu/faketree.htm

Anyone know what the cranks are?

Yes they are first generation Campagnolo Record carbon, 2001 or 2002 I think.

Dibs before it crunches into a black hole

+1 for Giro LX. I have the long finger ones, now looking for black fingerless L for a decent price online...

Nice to see Biz has lost some weight.

Get out of the pool

Riding fixed is like playing water polo on a horse

Jamaïcain skid.

Does anyone know if Strava will accept GPS coordinates including altitude from altimeter-equipped GPS devices other than Garmin? From what I understand Strava uses only latitude-longitude from smartphones and GPS without altimeters, and latitude-longitude-altitude for specific Garmin models.

This is so weak
http://road.cc/content/news/89191-lance-armstrong-legal-team-moves-dismiss-federal-fraud-lawsuit

I don't think you can stream local media, at least as announced.

Anyone here fluent in French and English and able to help me with some translating? I really don't think my translations are cutting the mustard, so would appreciate a second eye to go over a few paragraphs for me.

If you're still looking, I'm French and maybe I can have a look at it if it's just a few paragraphs.

Thanks for the wheel advice. Do Shimano sell wheels compatible with a Campagnolo drive train ? Or would I have to change the freewheel body ?

A question about wheels. I'm thinking about upgrading my Mavic Aksiums on the road bike.

I mostly ride 1000 m D+ for every 50 km. I'd like to stay with clinchers and I tend to brake a lot on descents, so no carbon for me I guess.

Is it worth it to upgrade for Campagnolo Neutrons (you can get them for ~300€ used)? Should I go for something else or keep the Aksiums?

French-speaking media comment sections, like l'Équipe, Rue89, Le Monde etc. are the worst, no matter the quality of the media/website. A bunch of arrogant know-it-all and angry bedwetters... Maybe it's because most of them discovered the internet last year, but still. Only on Youtube can you find something worst in english.