The tunning systems of conventional American invented drum sets are designed originaly for calf skin heads which were not as uniformly mounted onto drums & had natural irregularities as well. The single flange rims, double flange & later the triple flange rims were evolved to enhance tunning & sticking & general durablilty. These early rims did flex to allow varying tensions at various tunning lug locations as the drummer fine tunned the focal tones of each drum * retunning was common w/ calf since it was affected by humidity & tempratures & just the act of playing. In time, these rims would warp & a drummer who cared enough, would replace the rim when he replaced the drum head. Since modern drumheads are more uniform & we play them harder than old days, the hardwares are still old school & need tweaking and care. In the case of Timbales which old models had shins mounted either directly to a cold rolled metal rim, the head was expertly mounted & stretched uniformly and rough tunned when wet so as it dried, you had relative even tunning and made fine tunning w/ less lugs acceptable. The heavy Cuban tunning system of nuts & bolts w/ crude lugs were also designed durring calf skin days and are not very scientific in light of modern designs in drum tunning systems we now see on drumsets thanks to innovators like George Way of the Leedy & Leedy / Ludwig companies. Most his innovations were adopted by the drumcompanies of his day & continue to be the standard today. Variations may include cast rims & retro wood rims but its still a system from the 30's/40's/50's still used on heavier torqued plastic heads. Most drums compensate by adding more tunning hardware + bulk, weight & mass which deadens the drum tone & resonance...not to mention the mounting sysyem bulk that at times are mounted to the Shells. Innovative drum builders like Nobble & Cooley, strive to find & design the happy medium of strength vs weight & maximum resonace of a drum shell & drum head w/ great looking finnished product. Cast metal tunning lugs & rims all are prone to breakage no matter how shinny the chrome plating may make them attractive ! Every drummer must be aware of his style of drumming and the kit & its hardware abilities to be a good fit for the gigs/jobs at hand. A jazz kit will have a diferent approach to tunnings & hardwares than a hard rock kit. Import companies took advantage of design flaws in American & European deigns in the 60's, Copied the ones that worked & advanced those designs in later models. All the principles had already been designed into drums but commercial objectives over powered musical ones & we buy whatever the hype tells us to buy ! ? Most drummers take little care in tunning so it wont matter if a crude sound is ok for them...regardless of the cost of the kit ! I have seen drums of crude design & materials...have more musical tone & simplicity of pracitical use than commercial drum sets. Mostly...its the drum head....I loved calf skiin over plastic , just as I love rawhides over plastics for Congas,bongos etc. Its got rebound, tone & every head has a uniqueness of sorts. Plastics have a limeted sweet spot and then its only benifit is durability, weatherproofness,and common availablility. Timbales dont have bottom heads so a good head of any kind must be well tunned and selected to produce musical tone & sustain as well as brightness & volumes. Most Timbales now are 14 " & 15 " steel shells & younger timbale drummers tune them so tight, they loose tone & sound too bright & tinny. They are trying to make large shells sound like smaller 13" & 14 " shells. The shell sizes & materials are key factors in timbales...just like any drum. % lug tunning can be as good as 6 lug tunnings but w/ less hardwares. But you need a true level bottom edge to mate w/ factory perfect heads, and a proper fitting true round rim as well. My simple deduction is : Drums designed for calf...will not be durable enough or properly fit plastic heads which can actualy damage the drums from these increased higer tension requirements of plastic heads. Cast lug casings can break or strip out the mounting screws, thinner shells can delaminate etc rims can warp out of shape. Vintage American drums...are American tech collectables...dont destroy the few remaining examples just to have a old style Radio King set to play heavy rock on !? Ernesto Pediangco.