diff --git a/src/Core/RideCache.cpp b/src/Core/RideCache.cpp
index 410ef2e46..9daf31457 100644
--- a/src/Core/RideCache.cpp
+++ b/src/Core/RideCache.cpp
@@ -287,6 +287,9 @@ RideCache::addRide(QString name, bool dosignal, bool select, bool useTempActivit
         // notify everyone to select the one we were already on
         context->notifyRideSelected(prior);
     }
+
+    // model estimates (lazy refresh)
+    estimator->refresh();
 }
 
 void
@@ -376,6 +379,9 @@ RideCache::removeCurrentRide()
 
     // now select another ride
     context->notifyRideSelected(select);
+
+    // model estimates (lazy refresh)
+    estimator->refresh();
 }
 
 // NOTE:
diff --git a/src/Core/RideCache.h b/src/Core/RideCache.h
index 92ab90633..f129088fd 100644
--- a/src/Core/RideCache.h
+++ b/src/Core/RideCache.h
@@ -132,6 +132,7 @@ class RideCache : public QObject
     protected:
 
         friend class ::Athlete;
+        friend class ::MainWindow; // save dialog
         friend class ::RideCacheBackgroundRefresh;
 
         Context *context;
diff --git a/src/Gui/SaveDialogs.cpp b/src/Gui/SaveDialogs.cpp
index 0042d79ae..3a31e4424 100644
--- a/src/Gui/SaveDialogs.cpp
+++ b/src/Gui/SaveDialogs.cpp
@@ -19,6 +19,7 @@
 #include "Tab.h"
 #include "Athlete.h"
 #include "RideCache.h"
+#include "Estimator.h"
 #include "GcRideFile.h"
 #include "JsonRideFile.h"
 #include "RideItem.h"
@@ -197,6 +198,9 @@ MainWindow::saveSilent(Context *context, RideItem *rideItem)
 
     // mark clean as we have now saved the data
     rideItem->ride()->emitSaved();
+
+    // model estimates (lazy refresh)
+    context->athlete->rideCache->estimator->refresh();
 }
 
 
diff --git a/src/Metrics/Estimator.cpp b/src/Metrics/Estimator.cpp
index 7ee7cf5fd..9ae2453ec 100644
--- a/src/Metrics/Estimator.cpp
+++ b/src/Metrics/Estimator.cpp
@@ -99,10 +99,51 @@ class RollingBests {
 
 Estimator::Estimator(Context *context) : context(context)
 {
+    // used to flag when we need to stop
+    abort = false;
+
+    // lazy start signal
+    connect(&singleshot, SIGNAL(timeout()), this, SLOT(calculate()));
+
     // when thread finishes we can let everyone know estimates are updated
     connect(this, SIGNAL(finished()), context, SLOT(notifyEstimatesRefreshed()));
 }
 
+void
+Estimator::stop()
+{
+    if (isRunning()) {
+
+        // we could use requestInterruption but would mean we need QT > 5.2
+        // and there isn't much value in that.
+        abort = true;
+
+        // now wait for the thread to stop
+        while(isRunning() && abort == true)  msleep(50);
+    }
+}
+
+// terminate thread before closing
+Estimator::~Estimator()
+{
+    stop();
+}
+
+// refresh
+void
+Estimator::refresh()
+{
+    printd("Lazy start triggered.\n");
+
+    stop(); // stop any running threads
+    singleshot.stop(); // stop any pending threads
+
+    // 15 secs delay before calculate() is triggered
+    singleshot.setSingleShot(true);
+    singleshot.setInterval(15000);
+    singleshot.start();
+}
+
 // setup and run, if not already running
 void
 Estimator::calculate()
@@ -184,6 +225,13 @@ Estimator::run()
     QDate date = from;
     while (date < to) {
 
+        // check if we've been asked to stop
+        if (abort == true) {
+            printd("Model estimator aborted.\n");
+            abort = false;
+            return;
+        }
+
         QDate begin = date;
         QDate end = date.addDays(6);
 
diff --git a/src/Metrics/Estimator.h b/src/Metrics/Estimator.h
index 594fe2887..416c1fd2d 100644
--- a/src/Metrics/Estimator.h
+++ b/src/Metrics/Estimator.h
@@ -38,13 +38,22 @@ class Estimator : public QThread {
     public:
 
         Estimator(Context *);
-
-        // sets up and kicks off thread
-        void calculate();
+        ~Estimator();
 
         // perform calculation in thread
         void run();
 
+        // halt the thread
+        void stop();
+
+        // cancel any pending/running and kick off with 15 sec delay
+        void refresh();
+
+    public slots:
+
+        // setup and run estimators
+        void calculate();
+
     protected:
 
         friend class ::Athlete;
@@ -53,7 +62,9 @@ class Estimator : public QThread {
         QMutex lock;
         QList<PDEstimate> estimates;
         QVector<RideItem*> rides; // worklist
+        QTimer singleshot;
 
+        bool abort;
 };
 
 #endif