Don't make life hard on yourself. Do it the easy way.
Buy one of these magnets because they are VERY strong and project a field up to 1/2 inch. Then put the magnet on the rim of your front wheel rim and glue the sensor on the bottom edge of your fender bracket (an invisible location).
(actually, buy like 4 of the little magnets as you find uses for them and the shipping costs are way way more than the cost of the 4 little magnets)
The stronger sensor "sender" magnet can bridge the larger air gaps between your motorcycle front wheel rim to the side of the front fender. You can mount your sensor under your fender next to the edge of the rim and put one of these on the top of the rim (narrow side out) exactly opposite from the air stem so as to not affect wheel balance adversely. This magnet is a "lengthwise" oriented magnet so it projects the strongest field distance from the narrow ends.
The Sigma unit is neat for our use because the wire length works out to be exactly what we need on a Savage when we do it with this stronger "sender" magnet to make the tucked under the fender across from the rim mount position for the sensor work correctly. Buy yourself at least 4 of the little magnets, because they double as BALANCE WEIGHTS for your tires (and they cost a lot less than the chrome plated lead spoke weights they sell for $7.00 EACH)
http://www.supermagnetman.net/product_info.php?products_id=346 Instructions on how to set the speedo up can be found on this excellent web page. Don't be fooled by the different model numbers, the same company makes both and your x06 is a newer version of the same speedo this guy is talking about.
http://www.geocities.com/toms_toys/bc80.htmlDo use the mile marker setting trick on the black background web page referred to above. If you take a trip on an interstate just stop at a mile marker and restart your computer as per his directions and write down all the info you get when you stop at a goodly distant mile marker. Mile markers are not dead nuts accurate as individuals, but when you are averaging say 40 to 100 of them you get a very very accurate setting for your speedo computer.
If you can't find it on the web page, here is the calculator that makes all this math and mm-to-mph translation dirt easy.
http://www.geocities.com/toms_toys/bc80c.html