Garmin hub speed sensor aerodynamics

[Hexsense]

@lelandjt: I use the measured tire circumference.

Change to measured distance from one complete wheel rotation with rider weight on?
Because tire compress and getting less circumference when there is a rider on the bike vs not.
Just mark chalk or dirt on a part of your tire then roll on flat ground, finally, measure distance between two marks on the floor.

[marcelflash]

[dim]

as I understand it, a speed sensor is important.

when you ride, you have a satellite recording your speed etc but it is high up in the sky and records in a straight line .... so when you are climbing a hill, or decending a steep hill, the satellite does not read accurately, as it see's you riding on a flat

I may be wrong but that's the way I understand it .... I have my speed sensor on the front wheel, as it's closer to my Garmin Edge

[Butcher]

Ribeye of course.

[Calnago]

Ribeye of course.

See, your advice is spot on! Don’t doubt yourself. Ribeye it is.

[kervelo]

@lelandjt: I use the measured tire circumference.

Change to measured distance from one complete wheel rotation with rider weight on?
Because tire compress and getting less circumference...

Yes, I could try that. However, I really don’t have any issue when all my bikes use speed sensors (Wahoo hub sensor or built in with my PT hubs). All bikes now measure identical distances for identical rides. The difference in distance is shown only if I used the GPS for distance.

[573]

Nice, thanks.

[PrimO]

I prefer the GSC10, it does two jobs with one unit rather than having the hub sensor for speed or the goddam ugly cadence sensor strapped to the crank.

I also have a very thin (2mm x 10mm) neodymium magnet on the spoke for the speed sensor and not an ugly round bulky thing like you usually see.

[alcatraz]

I stopped using mine after a battery change or two. Less sensors means less stuff that can fail. Gps works ok except in tunnels.

Something odd has happened to my garmin 520 though. It seems even without any speed sensors added the speed reading is zero for a few minutes.

Gps lock usually occurs fast. I can't imagine that being the reason.

[skidrrr]

Looks good but why font wheel? I think that putting it on a back wheel is even better.

[ms6073]

I may be wrong but that's the way I understand it .... I have my speed sensor on the front wheel, as it's closer to my Garmin Edge

The satellite is not recording anything, your GPS enabled device is using calculating position based on differences in arrival times of signals transmitted by the orbiting satellites. Here is a link to site with an explanation of How Does GPS Work?.

[jfranci3]

just to answer the orginal question... the rear hub is in some pretty dirty air and in a vacuum. If you can run it back there, you're probably not going to see more than a gram of difference. If you're concerned about it, run a rear chainstay sensor.

[marcelflash]

Ordered the Garmin Speed 2 sensor, looks more aero. Should arrive in 2 weeks.

[wheelsONfire]

Probably better to move the sensor to the rear wheel

[Swannie]

Ordered the Garmin Speed 2 sensor, looks more aero. Should arrive in 2 weeks.

It's smaller, fits better on my dt hub. Got mine a few days now: