Advertise on Bikeforums.net



User Tag List

Results 1 to 7 of 7
  1. #1
    Rookie
    Join Date
    Nov 2011
    Location
    Baytown Texas
    Posts
    38
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Cateye Micro Wireless speed incorrect

    I installed a New Cateye CC-MC200W
    Micro Wireless on my New Rockhopper 29. I set the wheel diameter at 2288 as per the instructions.
    I've checked it against 2 seperate GPS units and it consistently read 2 mph slower,
    Any ideas? Could I adjust the numbers up or down a little to correct?

    thank you
    Dave
    2015 Trek Superfly 5
    2015 Rockhopper Sport 29

  2. #2
    Senior Member
    Join Date
    Aug 2014
    Location
    Halifax, NS
    My Bikes
    Peugeot Evasion
    Posts
    79
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Did you measure your circumference or take it from the chart.

  3. #3
    Rookie
    Join Date
    Nov 2011
    Location
    Baytown Texas
    Posts
    38
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by WarrenR View Post
    Did you measure your circumference or take it from the chart.

    I took the number from the Cateye instructions

    thanks
    Dave
    2015 Trek Superfly 5
    2015 Rockhopper Sport 29

  4. #4
    Senior Member RoadTire's Avatar
    Join Date
    Mar 2012
    Location
    Minnesota
    My Bikes
    '09 Trek 2.1 * '75 Sekine * 2010 Raleigh Talus 8.0 * '90 Giant Mtb * Raleigh M20 * Fuji Nevada mtb
    Posts
    1,942
    Mentioned
    5 Post(s)
    Tagged
    3 Thread(s)
    You probably have a "custom wheel size" option, us that instead of the presets. Make a change, ride, check, change, ride, check .... until it's averaging the same as the GPS. You will always get some variation, but it will be both > and <.

    I do this on my road bikes, using my phone cycling app, and most of the time the same rides come in within 1 %, other times they are 5% or so. Depends on the GPS signals at the time.
    Last edited by RoadTire; 11-02-14 at 06:38 AM.
    FB4K - This December, 2014, 5288 kids received bikes for Christmas. For many, it was their first bike, ever. Every bike, new and used, was donated, built, cleaned and repaired. That amounts to well over 10,000 volunteer hours this fall, just in the Twin Cities. Check us out on FaceBook: FB4K.
    Disclaimer: 99% of what I know about cycling I learned on BF. That would make, ummm, 1% experience. And a lot of posts.

  5. #5
    Senior Member Looigi's Avatar
    Join Date
    Dec 2010
    Posts
    8,018
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Or: Measure the actual circumference of the tire using the roll-out method. Stand the bike up on a smooth surface. Position the wheel with the sensor with the valve stem at the bottom. Mark the floor directly below the valve stem, roll the bike forward one wheel rotation and mark the floor when the valve is again at the bottom. Measure the distance between the marks to get the tire circumference. Weighting the bike as it would be while riding will improve the accuracy and yield a slightly lower number, roughly 1% lower.
    Eschew simplistic dogma.

  6. #6
    Senior Member RoadTire's Avatar
    Join Date
    Mar 2012
    Location
    Minnesota
    My Bikes
    '09 Trek 2.1 * '75 Sekine * 2010 Raleigh Talus 8.0 * '90 Giant Mtb * Raleigh M20 * Fuji Nevada mtb
    Posts
    1,942
    Mentioned
    5 Post(s)
    Tagged
    3 Thread(s)
    Looigi is correct - that works too.

    Alternate methods, obsessions, and general attitude are described in this thread. Pretty entertaining:


    confused about calibrating bike speedometer
    FB4K - This December, 2014, 5288 kids received bikes for Christmas. For many, it was their first bike, ever. Every bike, new and used, was donated, built, cleaned and repaired. That amounts to well over 10,000 volunteer hours this fall, just in the Twin Cities. Check us out on FaceBook: FB4K.
    Disclaimer: 99% of what I know about cycling I learned on BF. That would make, ummm, 1% experience. And a lot of posts.

  7. #7
    Senior Member
    Join Date
    Aug 2014
    Location
    Halifax, NS
    My Bikes
    Peugeot Evasion
    Posts
    79
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    This

    Quote Originally Posted by Looigi View Post
    Or: Measure the actual circumference of the tire using the roll-out method. Stand the bike up on a smooth surface. Position the wheel with the sensor with the valve stem at the bottom. Mark the floor directly below the valve stem, roll the bike forward one wheel rotation and mark the floor when the valve is again at the bottom. Measure the distance between the marks to get the tire circumference. Weighting the bike as it would be while riding will improve the accuracy and yield a slightly lower number, roughly 1% lower.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •