Author Topic: Sigma BC1200 Cyclometer Installation ( ST1100 ) *  (Read 11834 times)

Offline KoTAOW

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Sigma BC1200 Cyclometer Installation ( ST1100 ) *
« on: December 07, 2007, 06:43:50 PM »
Sigma BC1200 Cyclometer Installation ( ST1100 )

Sigma BC1200 Features

1. KMH / MPH                                     speed readout up to 183 mph / 300 kmh
2. TRP                                               trip distance
3. CLK                                                clock - 12hr ( mph ) / 24 hr [ kmh ]
4. STP                                               riding time - auto start/stop
5. MAX                                               maximum speed
6. AVS                                               average speed
7. + -                                               comparison - actual / average speed
8. WS                                                2 wheel size programmable
9. DST 1 / DST 2                                 2 odometer logs - each up to 99,999 miles
10. TOTDST                                        total riding distance. DST 1 + DST 2
11. CAD                                              cadence - accessory is seperate
12. TOT                                              toal riding time, aggregate stop watch

The Sigma BC1200 cyclometer provides an extremely accurate odometer/speedometer alternative to the notoriously optimistic Honda stock speedometer. Over the production run of the ST1100, it has been determined that ST's speedometer runs a fairly consistent 5-7% ABOVE actual ground speed. Curiously, the odometer does not share this optimism; indeed, the stock odometer seems to be quite accurate.
The Sigma series of cyclometers has been a favorite accessory add-on among the Long Distance community over the years. Endurance rallies are all about time/speed management, thus the Sigma is an excellent and extremely useful weapon in the Endurance Rider's arsenal.
There are many mounting opportunities in the ST1100's cockpit to allow placement of the display module in a good location for viewing while underway. I took this concept to the max by mounting my Sigma in a heads up display (HUD) manner: it is affixed on the top center portion of the windscreen, under the SEANG edging, directly in my line of sight, as shown in the photo below:

And you can see from the bug-splattered windscreen, this photo was taken at the end of a Nevada rally (note max speed since reset! :^)
Small 26-gauge wire was used to connect to the input leads on the rear of the Sigma, and then routed underneath (inside) the SEANG edging for a clean, wire-free appearance. This HUD placement means I never have to take my eyes off the road and look down at the dash area to read my speed. Sweet.
Critical to a properly functioning Sigma is the rock-solid mounting of the pickup sensor and magnet. While many like to mount the sensor and magnet on the front wheel, I wanted to avoid any potential impact damage from small rocks, road debris, etc. So I elected to use the rear wheel to mount the sensor. I fabricated a small 'L'-bracket out of a small piece of aluminum, and used 5-ton clear epoxy to affixed both the 'L'-bracket and magnet to the wheel, as depicted below:

Discard the magnet that came with the Sigma in favor of a small rear earth magnet found at any Radio Shack store. The magnet is epoxied to the small "dimple" found in the middle of any of the three "spokes" of the wheel; the 'L'-bracket (with sensor appropriately zip-tied in place) is also epoxied into place at the top of the rear drive housing, on the inner nylon ring. Note how wire feed is encased in loom and zip-tied extensively to preclude damage.
But whichever wheel or sensor placement you select, ensure you follow the instructions for calibrating the wheel circumference closely. An accurate wheel measurement is critical to an accurate speedometer display.

Original write-up posted by 'Warchild', re-posted here with thanks to STOC'er Tom Melnik.
« Last Edit: January 16, 2013, 07:47:51 AM by Tom Melnik »