Quoted message said:Quoted message said:
BobT wrote:
I'm having difficulty installing my Polar power sensor.
Quoted message said:Quoted message said:"Qui si parla Campagnolo" <[email hidden]> wrote in message
news:[email hidden]...
Probably don't want to hear this but get a refund and get a Powertap
Pro rear wheel. More accurate, easier to set up, all around a better
system that relies on chain frequency.
Thanks, but you are right, I didn't want to hear that. In fact, I would
love to have a Powertap Pro (or SRM for that matter) but I paid $250.00 for
my Polar unit compared to $900.00 plus a wheel build. Based on head-to-head
comparisons I've seen on the web, I'm hoping to get reasonable results with
this much less expensive product.
"JayofMontreal" <[email hidden]> wrote in message
news:[email hidden]...
Quoted message said:There is no rule with regards to the mounting of the magnet, nor what
magnet to use. Try a rare earth magnet. They are very powerful and you can
mount it quite a distance from the pickup and still get a reading.
I tried using several rare earth magnets I purchased from Radio Shack to no
avail. The problem is that the chainstay is 4 cm from the inside of the
crankarm where the cadence sensor needs to be. If I mount the power /
cadence sensor on top of and parallel to the chain stay, I'm going to need a
really strong magnet. In fact, when I put 4 of the 1/8" Radio Shack rare
earth magnets in place, they pulled the chain against the crankarm magnets
but didn't trigger the cadence sensor.
I have reached a solution that I will post here for others who might have
this problem in the future.
For the shape of my chainstay and my chainline (Onix Orbea, Shimano Ultegra
10-speed triple), I need to mount the power / cadence sensor at an angle to
the chainstay with the front of the sensor outboard. I made a spacer that I
zip tied to the outside of the front of the chainstay. I then zip tied the
front of the sensor to the top of the spacer positioning the front of the
sensor much closer to the crankarm. I think one could make a spacer to move
the front or back of the sensor up or down or inboard or outboard.
I made the spacer out of wood. Plastic like Nylon or Delrin might be better
but I couldn't find any locally. First, I measured how much above the top
and how much outboard of the outside of the chainstay I needed to position
the sensor. I used a contour gage to transfer the shape of the chainstay to
a small block of wood. I then used a Dremel tool to shape the inboard side
of the wood to fit the chainstay. I then shaped the upper outboard part of
the block to fit the sensor at the correct position. I cut a shallow
channel for the zip tie. I finished the wood to protect it from the
elements. Now the system works!
BobT