diff --git a/README.md b/README.md
index 8930d8f..632476d 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 Design of a highly experimental recumbent tricycle, not software at all.
 
-![Early sketch of the tricycle](tricycle-2b-export.svg)
+![Subframe and four bar linkage](subframe-and-fourbar.png)
 
 ## Status
 
@@ -20,7 +20,6 @@ The following libraries are used into this model. They should be downloaded and
 | [Sprocket Generator V2](https://www.thingiverse.com/thing:3059422) | SprocketGenerator2 | [Hampus Andersson](https://www.thingiverse.com/haand001/designs) | [Creative Commons Attribution](https://creativecommons.org/licenses/by/4.0/) |
 | [NACA Airfoils - 4 digit fully parametric](https://www.thingiverse.com/thing:898554)] | NACAAirfoils       | [Rudolf Huttary](https://www.thingiverse.com/parkinbot/designs) | [Creative Commons - Attribution - Non-Commercial](https://creativecommons.org/licenses/by-nc/4.0/) |
 | [The Belfry OpenScad Library, v2](https://github.com/BelfrySCAD/BOSL2) | BOSL2              | Numerous contributors                                        | [BSD 2-Clause](https://github.com/BelfrySCAD/BOSL2/blob/master/LICENSE) |
-|                                                              |                    |                                                              |                                                              |
 
 
 
diff --git a/model/subframe.scad b/model/subframe.scad
index aefe693..b93bfc1 100644
--- a/model/subframe.scad
+++ b/model/subframe.scad
@@ -1,4 +1,4 @@
-// tricycle.scad: 
+// subframe.scad: 
 
 // (c) Simon Brooke 2025; CC-BY-SA
 
diff --git a/subframe-and-fourbar.png b/subframe-and-fourbar.png
new file mode 100644
index 0000000..db78f55
Binary files /dev/null and b/subframe-and-fourbar.png differ