I do have a concern regarding the design.
What is holding the clutch plates on the flywheel is a collection of eight bolts and eight aluminum stands. The diaphragm spring housing is not directly attached to the flywheel. So, evidently the flywheel drives the eight bolts which drive the plates via the aluminum stands, unless they are steel, of course, but having torque resisted by a bolt that is experiencing most of its stress in single shear is not something I would regard as a recipe for long-term reliability.
In fact, single shear is one of the worst-case scenarios, especially if it is combined with an additional bending load from leverage of the furthest component, namely the spring housing, and the plates as one continues further from the flywheel.
Evidently, the clutch steel plates slide up and down these stands during normal operations. This is a source of wear.
Assuming the maximum torque of the three-disk version, 1515 foot-pounds, with six friction surfaces total, one of which is the flywheel and does not count in the pressure places on the stands, so 1515/6X5 =1262.5 foot-pounds experienced by the eight bolts and stands. or 157.1825 foot-pounds dedicated to each of the 22.5 degree slices of the assembly. Since the eight stands are about 10 inches in diameter in their bolt circle, the torque is one foot/10 inches X 157.1825=189.375 pounds of force exerted on each stand at the rated torque. This is not a static load, but it is sliding up and down that stand every time the clutch is engaged.
The McLeod has a one-piece stamped cover, that experiences no friction or movement. However, the intermediate clutch disk still has to move a bit during clutch disengagement and engagement, and it is supported by three bolts, evidently, but they are not in single shear, but have one end secured to the flywheel or whatever McLeod bolts thereto, and the other end supported by the stamped clutch cover which is bolted to the flywheel, so on the McLeod unit, the bolts undergoing the most stress are mounted in double shear, which is the ideal shear situation, and though there is movement up and down said bolts of the clutch disk, it is taking only 1/2 of the torque (the other half borne by the clutch housing and the flywheel, which is retained with separate, shorter bolts) and the parts experiencing said sliding are made of steel.
3/8 as many surfaces, each surface (given same torque values) would experience 303 pounds of force at rated torque. on a smaller area, as there is only one additional disk in the Mcleod.
Conclusion: my main concern on the Mantic or similar designs with a pressure plate floated off the flywheel standing only on bolts with stands around them is that the aluminum stands would wear over time and/or loosen, being fastened in single shear and for the Mantic, bolted into an aluminum flywheel.
I like the idea of an aluminum flywheel, but not combining single shear bolt mounting with said aluminum.
I would think a single-piece stamped or billet aluminum pressure plate bolted directly to the flywheel would be more desirable, with the clutch disks moving on hardened steel bolts/rods/whatever that are mounted in double shear with said pressure plate.
I don't know of any long-term reviews of either brand, though. I could do some more research. I think it is possible that through-bolting the eight stands (as in putting an additional nut on the far side of the flywheel in addition to the existing threads in the flywheel and using high-strength steel stands could provide more clamping power and thus more stabilityfor the stands and greater longevity.
