Tuning HiT Clutch – Road Test

Tuning HiT Clutch – Road Test

Tuning HiT Clutch

Test Condition

  • Original Variator
  • Original Ramp Plate
  • Original Boss
  • Original Fan
  • Original Torque Spring
  • Sliding Roller Weight, SR1814-6, 16g
  • Original Driven Pulley
  • Original Clutch Bell
  • Original V-Belt
test environment

  The road for the riding test is beside a windbreak forest, which is not affected by the weather and wind, the only disadvantage is that the distance is not long enough.

Kymco Famous 125

Kymco Famous 125c.c
Vehicle weight is 110 kg (243 lb)


  Additional load is 130kg (286 lb), equivalent to about 20 degrees of climbing or headwind of grade 4~5. Why choose this weight? Because sometimes it takes adversity to better discern whether a horse is good or not.

Tire pressure

Tire pressure is 28 psi.

  Tire pressure will affect acceleration so we need to maintain the tire pressure of 28 psi for all testings to avoid any error due to tire pressure variation.

All test conditions are the same, only the clutch is different.

What to test? And what is the difference ?

test route

Test the acceleration time needed to reach distance: 402 meter (1/4 mile)

HiT Clutch 181401

  Dr.Pulley, HiT Clutch, HiT181401 will test the following three specifications of Pillow Springs.

PS 11 kg, PS 20 kg, PS 25 kg, each test 5 times to get the average value.

Original Clutch

  The original clutch is tested 5 times to get the average value.

  Both Clutches Engaged RPM are 1550.

  To understand the detailed mechanism of HiT clutch, the official website link is attached below for first-time users’ reference.

Primary film begins

Original Clutch

ItemTime (s)
0~50 km/hr7.0
0~80 km/hr23.7
0~402 m23.8

HiT181401, Pillow Spring 25 kg

ItemTime (s)
0~50 km/hr7.3
0~80 km/hr24.8
0~402 m24.1

HiT181401, Pillow Spring 20 kg

ItemTime (s)
0~50 km/hr6.8
0~80 km/hr23.7
0~402 m23.8

HiT 181401, Pillow Spring 11 kg

ItemTime (s)
0~50 km/hr6.3
0~80 km/hr22.4
0~402 m23.4

Summarized Comparison (Conclusion)

Average dataOriginal clutchHiT181401
PS 11 kg
0~50 km/hr7.0 sec6.3 sec
0~80 km/hr23.7 sec22.4 sec
0~402 m23.8 sec23.4 sec

  Actually, during this testing period , we not only have tested PS springs, but also CS springs. For the Kymco Famous 125 scooter and a carrying load of 130kg, the test results were classified into three levels. The following are provided for reference.

HiT Clutch
1550 rpm, 11 kg
HiT Clutch
1550 rpm, 20 kg
HiT Clutch
1360 rpm, 20 kg
<Best combination>HiT Clutch
1550 rpm, 25 kg
HiT Clutch
1650 rpm, 20 kg
HiT Clutch
1360 rpm, 11 kg
HiT Clutch
1360 rpm, 25 kg
*Rpm mean engaging RPMHiT Clutch
1650 rpm, 11 kg
HiT Clutch
1650 rpm, 25 kg
*KG mean Pillow SpringOriginal Clutch

Youtube Video

More Information

Our Youtube url : https://www.youtube.com/c/DrPulley

Online Shop : High Thrust Clutch