Question about Sigma Cycling

1 Answer

I replaced the battery in a Sigma bicycle computer(BC 506). I need a manual to reset the wheel size and set/reset the speed, miles, time, total miles, time of day. Can you refer me to a pdf download?

Posted by Gail Schott on


1 Answer

Donald Ayers-Marsh

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • Sigma Master
  • 1,389 Answers

Google "sigma bc 506 manual" or contact Signma:

I’m happy to help further over the phone at

Posted on Aug 26, 2017


2 Related Answers


  • 119 Answers

SOURCE: A code for 27inch 700 wheels for sigma bicycle computer needed

Dear spinnerrr

  • Multiply the wheel diameter in mm or cm by 3.14.
  • Measure the distance travelled in one complete turn of the wheel.
this is the four digit number you are looking, it should be between 2145 and 2149


Posted on Mar 28, 2008


David Dunn

  • 8546 Answers

SOURCE: I have a sigma 506

Roll the wheel one revolution and enter the ditance in millimeters..

Posted on Sep 16, 2011

Add Your Answer


Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Turning off a sigma bc 506

Sigma bicycle computers go to sleep after a programmed time.

Jun 12, 2017 | Sigma Cycling

2 Answers

Sigma BC 1609 Cadence Bicycle Speedometer reads my movement much slower than I am actually going. E.g. moving about 15, reads as 5 mph.

I had the same problem. It is caused because the mount is facing the wrong direction and your computer is swapping speed and cadence. 5 mph would mean 63 RPM of the wheel which probably what your pedal is actually doing. The wheel is actually turning at about 3 times that rate so if you check your cadence it is probably maxing out at 180 even though that wouldn't be possible.

To fix this, just twist your mount 180 degrees on your handlebars or stem and try again. That way the computer is correctly lined up with the mount.

Mar 10, 2012 | Sigma Sport BC 1609 Cadence Wired Computer

1 Answer

Need help reseting for tire size 26x2.1 changed to road tires can't find my book it's a sigma bc 906

you can measure your wheel by placing your bike on a flat surface with the valve stem on the wheel in the bottom most position or 6 o clock position. mark the floor where the valve stem is. now roll the bike forward so that the wheels gets one full revolution and the valve stem comes back to the 6 o clock position and mark the floor at the valve stem. now get a tape measure and measure the distance between your two marks. Convert this measurement to usually centimeters. that will be the number that put into your computer.

the manual can be downloaded here


Bicycle Parts and Accessories

Jul 03, 2009 | Sigma Bc 906 Computer

Not finding what you are looking for?
Cycling Logo

Related Topics:

816 people viewed this question

Ask a Question

Usually answered in minutes!

Top Sigma Cycling Experts

Michael Thomas
Michael Thomas

Level 3 Expert

3053 Answers

Vincent G
Vincent G

Level 3 Expert

2363 Answers

The Knight
The Knight

Level 3 Expert

76416 Answers

Are you a Sigma Cycling Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides