Tandem Cycling - Incredible Tandem Cadence Sensor Mounting Bracket Thing (patent pending)

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.




andr0id
04-25-09, 08:03 PM
I've got two pretty inexperienced stokers that are very enthusiastic, but often don't realize when the cadence has dropped to a crawl. I tried the typical mounting on the left chain stay, but as others have experienced, the magnet on the crank arm pulled at the timing chain.

I figured the cleanest place to put the sensor would be on the captain's right arm if I could just figure out an easy way. After about cruising the PVC section of the hardware store, I think I came up with a pretty decent solution.

I found this CPVC T joint for a whopping 45 cents. It looked promising as it was about the same diameter as a chain stay and about as long as my Garmin sensor.



I reverse wrapped the boob tube with sandpaper to match the contour on the T joint.


Bracket after contouring the bottom of the T to fit the boob tube and grinding out a few holes with the Dremel for a wire tie.


Now the fun part, assembling the sensor to the bracket.


Mounting it to the bike. I was hoping I could use two wire ties, but one worked fine and it is on pretty snug.




We have a Garmin front and rear from our singles, so we just made both of them learn the same cadence sensor. Works like a charm. Now I just have to wind tunnel test it to determine if I should leave the hole open. I'll probaby paint it black too. Oh, and I did trim the wire tie after I took the picture.


TandemGeek
04-25-09, 08:54 PM
Necessity is the mother of invention: a similar solution for a smaller SigmaSports HAC4 cadence sensor that I described in a July '07 posting: http://www.bikeforums.net/showpost.php?p=4807771&postcount=5

apage4u
04-26-09, 06:16 AM
This is not as clean as mounting to the eccentric but it was quick and easy.
I use a metal rod from with a flat end and a hole in it from a screen door. Mounted it to a bottle cage screw.


PDub62
04-26-09, 08:52 AM
What problem did you have with the cadence sensor mounted on the chainstay? We have ours mounted there and have never had a problem. I realize that it will pull the timing chain but the only time I've seen it have an effect is if the pedals stop with the magnet near the chain. No big deal right?

andr0id
04-26-09, 09:02 AM
It was making a ticking noise on every pass as it pulled the chain. I can't have ticking noises as I hate them. Although I now realize I could try the timing ring on the inside of the spider trick.