Combobox zeigt nichts an

Private Sub ComboBox1_Change()
ComboBox1.AddItem "60"
ComboBox1.AddItem "80"
ComboBox1.AddItem "100"
ComboBox1.AddItem "120"
ComboBox1.AddItem "140"
ComboBox1.AddItem "160"
ComboBox1.AddItem "180"
ComboBox1.AddItem "200"
uBreite = ComboBox1.Value
End Sub

Private Sub maxKraft_Berechnung()
If uBreite = "60" Then
maxKraft = ((3 * 210000 * 31.6 * (Worksheets("Tabelle1").Range("C3").Value) * (Worksheets(" _
Tabelle1").Range("C3").Value) * Traegerdurchbiegung) / ((0.5 * (Worksheets("Tabelle1").Range(" _
C3").Value) * (0.5 * (Worksheets("Tabelle1").Range("C3").Value) * (0.5 * (Worksheets("Tabelle1").Range("C3").Value)) * 30 * 30 * 30))
Else
End If
End Sub

Private Sub TextBox4_Change()
maxWasserhoehe = TextBox4.Value
End Sub