How to measure BCD size?
Measure the distance from the Center of a chainring bolt to the center of the crank. That gives you the bolt circle radius. Multiply that by 2 and you get the bolt circle diameter. Bolt Circle Diameter (BCD) is the diameter of the circle that goes through the center of all of the bolts on your chainring. On bicycle chainrings, this dimension is usually measured in millimeters. It is critical to know the BCD of your crankset when you are selecting a new chainring for your bike.
How to pick a BCD?
When it comes to choosing the right BCD, lots of factors will affect your decision. You’ll want to consider how much to spend, which type of BCD goes best with your diving style, how much weight you carry, where you want the jacket’s air to sit on your body, and even your body type. How can I know if the BCD I have chosen will be my size and fit correctly? While it’s always best to try on a dive suit or a BCD in a dive shop, SCUBAPRO provides a sizing chart for each BCD that matches a diver’s height and weight to each BCD size. It also provides the BCD’s lift capacity and dry weight.
How to calculate a BCD?
If anyone knows the binary representation of the numbers 0 to 9, he/she can make a BCD code of any number because, in BCD, we just convert each individual digit of any number to binary and then write them together. The Binary-Coded Decimal (BCD) representation of the decimal number 42 is 0100 0010.In the 8421 code, the weights linked with 4 bits are 8, 4, 2, 1 from MSB to LSB. That is, the weight of the 3rd bit is 8, the weight for the 2nd bit is 4, the weight linked with the 1st bit is 2 and the weight associated with the 0th bit is 1. Below is an example to understand the 8421 code.The weights of the individual positions of the bits of a BCD code are: 23 = 8, 22 = 4, 21 = 2, 20 = 1.BCD Code uses four bits to represent the 10 decimal digits of 0 to 9. BCD code is often called 8421 because the BCD is a weighted code and the weights used in binary coded decimal code are 8, 4, 2, 1.
Is my BCD too big?
If someone is diving with a BCD that is too big, the jacket will shift around during the dive. A too small BCD will sit too high on the waist or squeeze the diver when inflated. Again, it would better for beginners to stick with jacket, back-inflate, or hybrid style BCDs.