diff --git a/src/Dispatcher.h b/src/Dispatcher.h
index 0abfa9ab..d32633f1 100644
--- a/src/Dispatcher.h
+++ b/src/Dispatcher.h
@@ -39,6 +39,7 @@ public:
   virtual float packetScore(float snr, int packet_len) = 0;
 
   virtual int getMaxTextLen() const { return 10 * 16; }  // default: non-JP
+  virtual int getMaxGroupTextLen() const { return 10 * 16; }  // default: non-JP
 
   /**
    * \brief  starts the raw packet send. (no wait)
diff --git a/src/helpers/BaseChatMesh.cpp b/src/helpers/BaseChatMesh.cpp
index 2003db44..220a375b 100644
--- a/src/helpers/BaseChatMesh.cpp
+++ b/src/helpers/BaseChatMesh.cpp
@@ -436,7 +436,8 @@ int  BaseChatMesh::sendMessage(const ContactInfo& recipient, uint32_t timestamp,
 
 int  BaseChatMesh::sendCommandData(const ContactInfo& recipient, uint32_t timestamp, uint8_t attempt, const char* text, uint32_t& est_timeout) {
   int text_len = strlen(text);
-  if (text_len > MAX_TEXT_LEN) return MSG_SEND_FAILED;
+  int max_len = _radio->getMaxTextLen();
+  if (text_len > max_len) return MSG_SEND_FAILED;
 
   uint8_t temp[5+MAX_TEXT_LEN+1];
   memcpy(temp, &timestamp, 4);   // mostly an extra blob to help make packet_hash unique
@@ -469,7 +470,9 @@ bool BaseChatMesh::sendGroupMessage(uint32_t timestamp, mesh::GroupChannel& chan
   char *ep = strchr((char *) &temp[5], 0);
   int prefix_len = ep - (char *) &temp[5];
 
-  if (text_len + prefix_len > MAX_TEXT_LEN) text_len = MAX_TEXT_LEN - prefix_len;
+  int max_len = _radio->getMaxGroupTextLen();
+  if (text_len + prefix_len > max_len) text_len = max_len - prefix_len;
+
   memcpy(ep, text, text_len);
   ep[text_len] = 0;  // null terminator
 
diff --git a/src/helpers/radiolib/RadioLibWrappers.h b/src/helpers/radiolib/RadioLibWrappers.h
index 6c1035de..dfa702ce 100644
--- a/src/helpers/radiolib/RadioLibWrappers.h
+++ b/src/helpers/radiolib/RadioLibWrappers.h
@@ -50,12 +50,21 @@ public:
   }
 
   int getMaxTextLen() const {
-    if (!isJapanMode()) return 10 * 16;  // default
+    if (!isJapanMode()) return 10 * 16;  // default 160 bytes
     uint8_t cr = getCodingRate();
-    if (cr <= 5) return 3 * 16;   // 48 bytes ~16 JP chars
-    if (cr == 6) return 2 * 16;   // 32 bytes ~10 JP chars
-    if (cr == 7) return 1 * 16 + 8; // 24 bytes ~8 JP chars
-    return 1 * 16;                 // 16 bytes ~5 JP chars
+    if (cr <= 5) return 64;  // 3874ms @ SF12/BW125/CR4-5
+    if (cr == 6) return 48;  // 3874ms @ SF12/BW125/CR4-6
+    if (cr == 7) return 32;  // 3678ms @ SF12/BW125/CR4-7
+    return 24;               // 3547ms @ SF12/BW125/CR4-8
+  }
+
+  int getMaxGroupTextLen() const {
+    if (!isJapanMode()) return 10 * 16;  // default 160 bytes
+    uint8_t cr = getCodingRate();
+    if (cr <= 5) return 64;  // 3710ms @ SF12/BW125/CR4-5
+    if (cr == 6) return 48;  // 3678ms @ SF12/BW125/CR4-6
+    if (cr == 7) return 39;  // 3907ms @ SF12/BW125/CR4-7
+    return 29;               // 3809ms @ SF12/BW125/CR4-8
   }
 
   virtual int16_t performChannelScan();