Here is Profile's Spline Drive sprocket, in 19mm to fit any 19mm 48-spline spindle crank. This ensures a nice snug fit and should finally eliminate that annoying up-and-down you get in your chain and of course is required if you are running bossless cranks. 

FOR SIZES NOT AVAILABLE PLEASE CONTACT US, WE CAN TRY TO ADD IT ONTO OUR NEXT PROFILE ORDER FOR YOU.

NOTE: Spline drive sprockets are not compatible with 2-piece cranks for Right Side Drive (not enough room for splines). Spline drive sprockets are compatible on Left Side Drive 2-piece cranks though.

• The brand new Profile Spline Drive sprocket is manufactured from 7075 Aluminum in the USA.
• This sprocket requires no sprocket bolt, instead it has a hardened CrMo steel insert in that matches up to the 48 splines in your Profile BB spindle.
• These can be used with all 19mm 48s spline cranks but Profile have some specific no boss Profile Cranks for a clean look and lighter set up.
• Sizes: 18-42T.
• 1/8 Teeth on all except 3/32" on 18T and 20T..