diff --git a/src/GUI/gearratiographitem.cpp b/src/GUI/gearratiographitem.cpp
index db4e4006..5c128466 100644
--- a/src/GUI/gearratiographitem.cpp
+++ b/src/GUI/gearratiographitem.cpp
@@ -7,16 +7,11 @@
 GearRatioGraphItem::GearRatioGraphItem(const Graph &graph, GraphType type,
   QGraphicsItem *parent) : GraphItem(graph, type, parent), _top(NAN)
 {
-	qreal val = NAN;
-
-	for (QMap<qreal, qreal>::const_iterator it = _map.constBegin();
-	  it != _map.constEnd(); ++it) {
-		if (it == _map.constBegin()) {
-			val = it.value();
-			_top = it.key();
-		} else if (it.value() > val) {
-			val = it.value();
-			_top = it.key();
+	for (int i = 0; i < graph.size(); i++) {
+		const GraphSegment &segment = graph.at(i);
+		for (int j = 1; j < segment.size(); j++) {
+			qreal dx = segment.at(j).s() - segment.at(j-1).s();
+			_map.insert(segment.at(j).y(), _map.value(segment.at(j).y()) + dx);
 		}
 	}