I'm sure this question has been asked, I've looked, looked and looked...
How do you ID an A riser from a B riser...
"A" handle is a 15" riser
"B" handle is a 19" riser
So where do I take the measurements from...
Also there are some writing on the top limb pocket...B and some numbers.
I have numerous 1 piece Bears, this is my 1st take down.
Thanks in advance

Bear has a history of changing their serial numbers, you can ask in the forum titled Trad History/Collecting they will know.  My 1980's Green Stripe S/N starts with a B-xxxx; and my newer Bubinga riser has the "A" in the S/N.  I haven't measured the "B" or the "A".  I don't think it makes any difference, Bear hasn't said, or changed the two risers.

The AMO standard is to measure the bow across the back.  The Bear TD "B" is 60" with their No. 1 limbs, and 56" on the "A" riser.  They are currently making the No. 1 and 2 limbs and maybe the No. 3 again.  On the "B" riser the combination makes a 60", 62" and 64"  on the "A" it would be 56", 58" and 60".  Hope that helps you.

My A riser is 16.5 inches from the end of the steel hardware to the other end of the steel hardware.

My B riser is a tad under 20.5 measured the same way.