Garmin hub speed sensor aerodynamics

Everything about building wheels, glueing tubs, etc.
Hexsense
Posts: 933
Joined: Wed Dec 30, 2015 12:41 am

by Hexsense

kervelo wrote:
Sat Mar 23, 2019 8:54 pm
@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.

by Weenie


User avatar
marcelflash
Posts: 125
Joined: Mon Sep 01, 2008 5:07 pm
Location: Zwaag Nederland

by marcelflash

Image

dim
Posts: 534
Joined: Fri Oct 13, 2017 11:25 am
Location: Cambridge UK

by 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
Trek Emonda SL6
Miyata One Thousand

Butcher
Shop Owner
Posts: 944
Joined: Sun Jan 03, 2010 4:58 am

by Butcher

Ribeye of course.

User avatar
Calnago
Posts: 8530
Joined: Sun Nov 07, 2010 9:14 pm

by Calnago

Butcher wrote:Ribeye of course.
See, your advice is spot on! Don’t doubt yourself. Ribeye it is.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

kervelo
Posts: 334
Joined: Wed Jan 21, 2009 6:58 am
Location: Finland

by kervelo

Hexsense wrote:
Sat Mar 23, 2019 9:08 pm
kervelo wrote:
Sat Mar 23, 2019 8:54 pm
@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.

User avatar
573
Posts: 337
Joined: Wed Sep 05, 2012 2:38 pm
Location: West Sussex, UK.

by 573

marcelflash wrote:
Sat Mar 23, 2019 9:14 pm
Image
Nice, thanks. :thumbup:

PrimO
Posts: 108
Joined: Thu Nov 20, 2014 8:49 pm

by 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
Posts: 2208
Joined: Mon Aug 29, 2016 11:19 am

by 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.

User avatar
skidrrr
Posts: 71
Joined: Fri Jun 29, 2018 12:25 pm
Location: Moldova

by skidrrr

marcelflash wrote:
Sat Mar 23, 2019 9:14 pm
Image
Looks good but why font wheel? I think that putting it on a back wheel is even better.

User avatar
ms6073
Posts: 2769
Joined: Fri Jul 23, 2004 8:24 pm
Location: Houston, Texas

by ms6073

dim wrote:
Sat Mar 23, 2019 9:33 pm
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?.
Michael - The Anaerobic Threshold is neither...

jfranci3
Posts: 705
Joined: Tue Jul 26, 2016 5:21 pm

by 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.

User avatar
marcelflash
Posts: 125
Joined: Mon Sep 01, 2008 5:07 pm
Location: Zwaag Nederland

by marcelflash

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

User avatar
wheelsONfire
Posts: 2953
Joined: Mon Jul 07, 2014 8:15 am
Location: NorthEU

by wheelsONfire

Probably better to move the sensor to the rear wheel
Bikes:

Ax Lightness Vial EVO Race (2018.12.21)
viewtopic.php?f=10&t=156137
Paduano Racing Fidia (kind of shelved)
Open *UP* (2016.04.14)


Ex bike; Vial EVO D

by Weenie


Swannie
Posts: 288
Joined: Thu Jan 11, 2007 3:48 pm
Location: Belgium
Contact:

by Swannie

marcelflash wrote:
Fri May 03, 2019 7:41 am
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:
Image
Image
Image
Image

Post Reply
  • Similar Topics
    Replies
    Views
    Last post