diff --git a/ball-link.scad b/ball-link.scad
index 66223aa..83425d7 100644
--- a/ball-link.scad
+++ b/ball-link.scad
@@ -1,5 +1,5 @@
 // Link with ends for ball inserts
-// (c) Vitaliy Filippov 2014, license: CC-BY-SA 3.0
+// (c) Vitaliy Filippov 2014, license: CC-BY-SA 4.0
 
 $fn=40;
 length=64; // 8U spacing between balls, like LEGO Black Link 9 (32293)
diff --git a/small-shock-piston.scad b/small-shock-piston.scad
index 9c45377..91db78a 100644
--- a/small-shock-piston.scad
+++ b/small-shock-piston.scad
@@ -1,5 +1,5 @@
 // Piston for LEGO 76537 - Small Shock Absorber with Extra Hard Spring
-// (c) Vitaliy Filippov 2014, license: CC-BY-SA 3.0
+// (c) Vitaliy Filippov 2014, license: CC-BY-SA 4.0
 // Printed with Slic3r, 0.1mm layer, 0.3mm first layer and support enabled.
 
 $fn=40;
diff --git a/tire/tire_81.6_50.scad b/tire/tire_81.6_50.scad
index a2973aa..0876f1c 100644
--- a/tire/tire_81.6_50.scad
+++ b/tire/tire_81.6_50.scad
@@ -1,10 +1,19 @@
-// LEGO-like tire 81.6x50... Dunno where it's 81.6, it's 84 in fact...
-// (c) Vitaliy Filippov 2014, license: CC-BY-SA 3.0
+// LEGO-like parametric tire...
+// (c) Vitaliy Filippov 2014, license: CC-BY-SA 4.0
 
 $fn=60;
-R=42; // outer radius
+
+// 81.6x50:
+
+R=40.8; // outer radius
 R_I=26.5; // innermost radius
+BEVEL=2;
+THICKNESS=2.5;
+PROT_DEPTH=1;
+PROT_L_WIDTH=2;
+PROT_A_WIDTH=2;
 B=2.5; // width of edge for the rim
+B2=B+2;
 B_W=1.6; // thickness of edge for the rim
 B_P=4; // position of edge for the rim
 W=50; // tire width
@@ -17,29 +26,54 @@ CUT_ANGLE=12;
 CUT_I_R=1.5;
 CUT_O_R=2;
 
-// 6-spoke variant
+/*// 6-spoke variant
 N_SPOKE=6;
 CUT_ANGLE=21;
 CUT_I_R=2.5;
 CUT_O_R=2;
+N_L=2;
 
-rim();
+// small
+R=22;
+BEVEL=1;
+THICKNESS=1.5;
+PROT_A_WIDTH=1;
+PROT_L_WIDTH=1;
+B=1.5;
+B2=B+0.5;
+R_I=15;
+CUT_O_R=1;
+CUT_BASE=5;
+W=20;*/
+
+translate([0, 0, W]) rotate([180, 0, 0]) {
+  rim();
+/*
+  // Support ...
+  translate([0, 0, SPOKE_THICKNESS+(R_I-2-CUT_BASE)/2+0.4]) cylinder(r=CUT_BASE, h=W-(SPOKE_THICKNESS+(R_I-2-CUT_BASE)/2+0.4));
+  translate([0, 0, W-(B_P-2-0.2)+0.4]) cylinder(r=R_I+B+2, h=(B_P-2-0.2)-0.4);
+  translate([0, 0, W-(B_P-2-0.2)-2-B+0.5+0.4]) difference() {
+    cylinder(r=R_I+B+2, h=(B_P-2-0.2)+2+B-0.5-0.4);
+    translate([0, 0, -0.5]) cylinder(r=R_I+B+0.4, h=1+(B_P-2-0.2)+2+B-0.5-0.4);
+  }
+*/
+}
 tire();
 
 module rim() {
-  translate([0, 0, B_P-2-0.2]) color([0.5, 0.5, 1]) {
+  color([0.5, 0.5, 1]) {
     difference() {
       union() {
-        cylinder(r=R_I-0.2, h=W-2*(B_P-2-0.2));
-        cylinder(r=R_I+B-0.5, h=2);
-        translate([0, 0, W-2*(B_P-2-0.2)-2]) cylinder(r=R_I+B-0.5, h=2);
+        cylinder(r=R_I-0.2, h=W-(B_P-2-0.2));
+        cylinder(r=R_I+B-0.5, h=2+(B_P-2-0.2));
+        translate([0, 0, W-(B_P-2-0.2)-2]) cylinder(r=R_I+B-0.5, h=2);
         hull() {
-          translate([0, 0, B_P]) cylinder(r=R_I+B+2, h=2);
-          translate([0, 0, B_P+B+2+0.2]) cylinder(r=R_I-0.2, h=2);
+          translate([0, 0, (B_P-2-0.2)+B_P]) cylinder(r=R_I+B2, h=2);
+          translate([0, 0, (B_P-2-0.2)+B_P+B2+0.2]) cylinder(r=R_I-0.2, h=2);
         }
         hull() {
-          translate([0, 0, W-2*(B_P-2-0.2)-6]) cylinder(r=R_I+B+2, h=2);
-          translate([0, 0, W-2*(B_P-2-0.2)-6-B-2-0.2]) cylinder(r=R_I-0.2, h=2);
+          translate([0, 0, W-(B_P-2-0.2)-6]) cylinder(r=R_I+B2, h=2);
+          translate([0, 0, W-(B_P-2-0.2)-6-B2-0.2]) cylinder(r=R_I-0.2, h=2);
         }
       }
       for (i = [1 : N_SPOKE])
@@ -49,10 +83,13 @@ module rim() {
         translate([(R_I-2-CUT_BASE)/2+CUT_BASE, 0, 0]) circle(r = (R_I-2-CUT_BASE)/2);
       translate([0, 0, SPOKE_THICKNESS+(R_I-2-CUT_BASE)/2]) cylinder(r=R_I-2, h=W);
       translate([0, 0, -0.5]) linear_extrude(height=W+1) axle();
-      translate([0, 0, -1]) cylinder(r=CUT_BASE-3, h=5);
-      hull() {
-        translate([0, 0, -1]) cylinder(r=CUT_BASE-2, h=1);
-        translate([0, 0, -1]) cylinder(r=CUT_BASE-3, h=2);
+      translate([0, 0, -1]) cylinder(r=CUT_BASE-2, h=5+(B_P-2-0.2));
+      difference() {
+        translate([0, 0, -1]) cylinder(r=1+R_I+B-0.5/*R_I-2*/, h=1+(B_P-2-0.2));
+        translate([0, 0, (B_P-2-0.2)])
+          scale([1, 1, (B_P-2-0.2)/((R_I-2-CUT_BASE+2)/2)])
+          rotate_extrude(convexity = 10)
+          translate([(R_I-2-CUT_BASE+2)/2+CUT_BASE-2, 0, 0]) circle(r = (R_I-2-CUT_BASE+2)/2);
       }
     }
   }
@@ -77,50 +114,55 @@ module rim_cut() {
 module tire() {
 difference() {
   hull() {
-    translate([0, 0, 2]) cylinder(r=R, h=W-4);
-    cylinder(r=R-2, h=W);
+    translate([0, 0, BEVEL]) cylinder(r=R, h=W-BEVEL*2);
+    cylinder(r=R-BEVEL, h=W);
   }
   // center hole through all piece
   translate([0, 0, -0.5]) cylinder(r=R_I, h=W+1);
   // top hole
   translate([0, 0, W-B_P]) cylinder(r=R_I+B, h=B_P+1);
   hull() {
-    translate([0, 0, W-1.5]) cylinder(r=R_I+B, h=1.5);
-    translate([0, 0, W]) cylinder(r=R_I+B+1.5, h=1);
+    translate([0, 0, W-BEVEL]) cylinder(r=R_I+B, h=BEVEL);
+    translate([0, 0, W]) cylinder(r=R_I+B+BEVEL, h=1);
   }
   // bottom hole
   translate([0, 0, -1]) cylinder(r=R_I+B, h=B_P+1);
   hull() {
-    translate([0, 0, 0]) cylinder(r=R_I+B, h=1.5);
-    translate([0, 0, -1]) cylinder(r=R_I+B+1.5, h=1);
+    translate([0, 0, 0]) cylinder(r=R_I+B, h=BEVEL);
+    translate([0, 0, -1]) cylinder(r=R_I+B+BEVEL, h=1);
   }
   // inside cut
-  translate([0, 0, B_P+B_W]) cylinder(r=R-3, h=W-(B_P+B_W)*2);
+  translate([0, 0, B_P+B_W]) cylinder(r=R-THICKNESS-PROT_DEPTH/2, h=W-(B_P+B_W)*2);
   difference() {
-    translate([0, 0, 2.5]) cylinder(r=R-3, h=W-2.5*2);
-    cylinder(r=R_I+B+2, h=W);
+    translate([0, 0, THICKNESS]) cylinder(r=R-THICKNESS-PROT_DEPTH/2, h=W-THICKNESS*2);
+    cylinder(r=R_I+B+THICKNESS, h=W);
   }
   // lateral protector
   for (i = [1 : N_L])
-    translate([0, 0, -1+i*W/(N_L+1)]) difference() {
-      cylinder(r=R+1, h=2.5);
-      translate([0, 0, -0.1]) cylinder(r=R-1, h=2.5+0.2);
-    }
+    translate([0, 0, -PROT_L_WIDTH/2+i*W/(N_L+1)])
+      difference() {
+        cylinder(r=R+1, h=PROT_L_WIDTH);
+        translate([0, 0, -0.01]) linear_extrude(height=min(PROT_L_WIDTH/2-0.1, PROT_DEPTH/2)+0.01, scale=(R-PROT_DEPTH)/(R+0.01)) circle(r=R+0.01);
+        translate([0, 0, PROT_L_WIDTH]) rotate([180, 0, 0]) translate([0, 0, -0.01]) linear_extrude(height=min(PROT_L_WIDTH/2-0.1, PROT_DEPTH/2)+0.01, scale=(R-PROT_DEPTH)/(R+0.01)) circle(r=R+0.01);
+        translate([0, 0, -0.1]) cylinder(r=R-PROT_DEPTH, h=PROT_L_WIDTH+0.2);
+      }
   // angular protector
   for (i = [1 : N_A])
     rotate([0, 0, 360/N_A*i]) protector_single();
   // to cut and look inside :)
-  //translate([0, 0, -0.1]) cube(size=[100, 100,100]);
+  translate([0, 0, -0.5]) cube(size=[R+10, R+10, W+1]);
 }
 }
 
 module protector_single() {
   difference() {
     union() {
-      translate([(W/2)/2, 0, W/2]) rotate([0, -45, 0]) cube(size=[2, R+4, sqrt((W/2)*(W/2)*2)]);
-      translate([-(W/2+2)/2, 0, 0]) rotate([0, 45, 0]) cube(size=[2, R+4, sqrt((W/2+2)*(W/2+2)*2)]);
+      translate([(W/2)/2, 0, W/2]) rotate([0, -45, 0])
+        cube(size=[PROT_A_WIDTH, R+4, sqrt((W/2)*(W/2)*2)]);
+      translate([-(W/2)/2, 0, 0]) rotate([0, 45, 0])
+        cube(size=[PROT_A_WIDTH, R+4, PROT_A_WIDTH+sqrt((W/2)*(W/2)*2)]);
     }
-    translate([0, 0, -0.5]) cylinder(r=R-1, h=W+1);
+    translate([0, 0, -0.5]) cylinder(r=R-PROT_DEPTH, h=W+1);
     translate([0, 0, W]) cylinder(r=R+10, h=10);
     translate([0, 0, -10]) cylinder(r=R+10, h=10);
   }
diff --git a/wakeboard/wakeboard.scad b/wakeboard/wakeboard.scad
index e969955..4790542 100644
--- a/wakeboard/wakeboard.scad
+++ b/wakeboard/wakeboard.scad
@@ -1,5 +1,5 @@
 // Simple wakeboard model
-// (c) Vitaliy Filippov 2014, license: CC-BY-SA 3.0
+// (c) Vitaliy Filippov 2014, license: CC-BY-SA 4.0
 // Print with Slic3r 1.1.3-dev rotated 45 degree to the edge with following settings
 // 0.1mm layer, 0.3mm first layer, enforce support for first layers = 40,
 // skirt distance = 0, skirt loops = 4, skirt height = 1 layer