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Old 08-07-09, 06:22 PM   #1
dorkypants
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Garmin GSC10 on Bike Friday?

Anyone successfully mount a Garmin GSC10 (speed and cadence sensor) on a Bike Friday, specifically an Air Friday? Looks to me like the distance between the cranks and the spokes on the back wheel exceeds the reach of the 2 sensors on the GSC10 !
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Old 08-09-09, 07:06 AM   #2
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Originally Posted by dorkypants View Post
Anyone successfully mount a Garmin GSC10 (speed and cadence sensor) on a Bike Friday, specifically an Air Friday? Looks to me like the distance between the cranks and the spokes on the back wheel exceeds the reach of the 2 sensors on the GSC10 !
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I see what you're saying. The pedals do not cross the arc of the wheel (and vis-versa)

Wheel RPM (speed) is either the primary or secondary source of MPH/KPH calculations ... depending on the Garmin GPS device you have. If the primary is not available, the device defaults to the secondary.
Either way, for the most part, MPH/KPH will be established with or without a wheel RPM (speed) sensor.

Cadence ... there is no substitue. It's either there or not. I would set the device to read cadence and then let the GPS receiver (via position and time) calculate your speed.

Unless you're good at disassembling small electronic devices and wiring a "jumper" wire between the two sensors ...
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Old 10-29-11, 12:34 PM   #3
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Anyone successfully mount a Garmin GSC10 (speed and cadence sensor) on a Bike Friday, specifically an Air Friday? Looks to me like the distance between the cranks and the spokes on the back wheel exceeds the reach of the 2 sensors on the GSC10 !
Well I have managed this for a Crusoe and the technique may work for you also. The trick is to realize you have somewhat more leeway fore and aft of the device. So I'm mounting on the brake arm using the optional rubber pad Garmin provide. See blog entry drrw.blogspot.com/2011_10_01_a*rchive.html

I also thought about mounting upside down on upper chain stay on drive side. Same trick - getting the sensors near to crankarm on one end, and button magnet on spokes for the arm on the other.
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Old 10-30-11, 02:08 PM   #4
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Hey dorkeypants....I'm a fellow BF owner. I personally don't use a cadence sensor on my BF. My philosophy is "the less you install on the bike...The less you have to remove/install each time you pack" Basically, if it takes more than 15 minutes to get in the suitcase or out again, you have too many accessories.

To that end I use a Garmin Forerunner 101. No wires, no sensors, and comes off with Velcro. My advice is to pitch the cadence sensor or use it on your 700C wheeled bike.

There is a mailing list called the "Yak" that consists of bike-Friday owners. I'm sure you are not the first person to encounter this problem. Post your question on the "YAK" and I would almost be willing to bet someone there has a solution. You can sign up for the YAK at the BF website.
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Old 10-30-11, 05:05 PM   #5
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Don't do it! If you don't have a wheel magnet within sense of the GSC10 and you tell your Garmin to read the GSC10, you'll see speed=0. We had trouble on our tandem with the magnet flinging to the outer end of the spoke on fast downhills, and speed=0 (and therefore auto-pause kicks in).
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Old 10-30-11, 05:06 PM   #6
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This has come up in the official Garmin users forums a few times with respect to folding bikes as well trainers. Some have removed the speed arm from the cadence sensor by removing the pivot screw that is loosened to adjust it, and then extended the wires so they could mount the speed arm separately from the body of the GSC10. The wires are pretty fine so it takes some care and skill with a soldering iron to accomplish successfully. FYI, GSC10s go for $30 with free shipping on Amazon.

With a Garmin 705 and 800, if the speed sensor isn't sending, the unit reverts to using gps for speed. I'm not sure about other models, but you could inquire in the Garmin forums. https://forums.garmin.com/forumdisplay.php?f=20
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Old 10-31-11, 06:49 PM   #7
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Originally Posted by Looigi View Post
Some have removed the speed arm from the cadence sensor by removing the pivot screw that is loosened to adjust it, and then extended the wires so they could mount the speed arm separately from the body of the GSC10. The wires are pretty fine so it takes some care and skill with a soldering iron to accomplish successfully.
If you need to splice the wires, it might be easier to start with a Wahoo or Timex sensor. DC Rainmaker spliced a Wahoo sensor, apparently pretty easily.
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Old 10-31-11, 07:22 PM   #8
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I have the GSC 10 and Cadence and Speed sensors working no problem!

The other posters clearly not reading what I'm saying. This works. It is easy. Set the Garmin computer to show you cadence and speed - match to ANT+ device connect - spin the back wheel - rotate pedal - watch display for readings. You can adjust until both display. I've been using this for a week now - and its working fine - and I hammer on my rides - 40mph top speed - rough roads - the works.

Because the wheel magnet is locked on to the nipple it is NOT flying anywhere.

There are NO wires to remove - the folding of the bike is NOT effected.

Note this is with 175 crank and 451 wheels - now for 170 cranks and 406 wheels - you may not have enough spread to play with - but you may - there is more tolerance than you think in the width that the GSC 10 will accept than Garmin's instructions make you think...
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Old 11-01-11, 07:27 AM   #9
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The other posters clearly not reading what I'm saying. This works. I've been using this for a week now - and its working fine - and I hammer on my rides - 40mph top speed - rough roads - the works.

Because the wheel magnet is locked on to the nipple it is NOT flying anywhere.
Oh good, you've "tested" this for a week. That's clinical experience, not testing. I've read what you said just fine.

Granted, on a BF you're apt to have the magnet at the end of the spoke, but we ride a tandem, with top speeds of 54, and we've seen the magnet dancing around far too often. (We've changed to another method of cadence reading, so the GSC10 came off the bike.)
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Old 11-01-11, 12:54 PM   #10
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The other posters clearly not reading what I'm saying. .
We all read it. We're just dismissing it is irrelevant.

The greatest distance I can get between the cadence magnet and the spoke magnet is ~9cm with the GSC10 arm maximally extended, and that's at about a 45 degree angle with respect to it's mounting surface. If you can get your magnets that close and mount the GSC10 at the appropriate angle, it might work.
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