GEAR SET 16*42 FOR 139QMB 49/50CC 4-STROKE ENGINES. THE FINAL DRIVE RATIO IS THE LAST BIT OF GEARING BETWEEN YOUR TRANSMISSION AND THE DRIVEN WHEELS. IN GENERAL, A LOWER FINAL DRIVE RATIO WILL LEAD TO LESS TORQUE AT THE WHEELS BUT HIGHER TOP SPEED. MEANWHILE, A HIGHER RATIO WILL RESULT IN THE OPPOSITE, I.E. MORE TORQUE AT THE WHEELS BUT LOWER TOP SPEED. GET THE MOST OUT OF YOUR BIG BORE KIT, WITH INCREASED TOP SPEED AND A MORE USABLE REV RANGE PERFORMANCE. HOCA GEAR SET 42/16 = RATIO 2.625:1 IS BEST FOR STOCK/MILD 70-90CC BUILDS. WE SUGGEST GOING TO THIS 16/42 TALLER GEAR SET IF YOU PLANNING ON PLAIN ROAD TOP-SPEED RIDING.

HERE'S HOW TO CALCULATE THE GEAR RATIO FOR HOCA GEAR SET 16*42 JUST DIVIDE THE NUMBER OF FINAL DRIVE GEAR TEETH 42 BY THE NUMBER OF THE COUNTER SHAFT TEETH 16. IT'S 42 / 16 = 2.625:1 GEAR RATIO. THIS MEANS THE 16-TEETH COUNTER SHAFT GEAR TAKES 2.625 FULL-TURNS TO DRIVE 1 FULL-TURN THE LARGER 42-TEETH DRIVE GEAR. OVERALL IT WILL TAKE LESS COUNTER SHAFT GEAR TURN FOR THE REAR WHEEL TO SPIN COMPARED TO THE STOCK GEAR RATIO. NOW YOU KNOW. GET THE MOST OUT OF YOUR BIG BORE KIT, WITH INCREASED TOP SPEED AND A MORE USABLE REV RANGE PERFORMANCE WITH THE RIGHT TRANSMISSION GEAR SET CHANGED BY TAIDA.

NOTE: NOT INCLUDED, MUST REUSE STOCK 52-TEETH COUNTER SHAFT GEAR OR PURCHASE PART# 1100-1322. A 12-TON HYDRAULIC COMPRESSOR IS REQUIRED FOR REMOVING THE STOCK 52-TEETH COUNTER SHAFT GEAR OFF ITS 15-TEETH COUNTER SHAFT AND THEN RE-PRESSING THE STOCK 52-TEETH COUNTER SHAFT GEAR ONTO THE NEW HOCA 16-TEETH COUNTER SHAFT. PLEASE COMPARE OE DIMENSION BEFORE ORDERING TO ASSURE CORRECT FITMENT.

SPECIFICATIONS:

INCLUDE THE FOLLOWING TRANSMISSION GEAR SET

• • 1X FRONT COUNTER SHAFT TEETH: 16 / SPLINES L: 24MM / OD: 27MM / OVERALL L: 56.7MM
• • GEAR PRESS-ON AREA L: MM X OD: 19.1MM / ENDS L: MM X OD: 12MM
• • 1X REAR FINAL DRIVE GEAR TEETH: 42 / INNER SPLINE: 19
• • OD: 80.9MM / ID: 18MM / W: 15.5MM
• • MADE IN TAIWAN
• • FIT QMB 49/50CC