Motorcycle Owners Club

Honda CG125 but also some universal motorcycle information

Honda CG125 MPH to RPM

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1999 CG 125 version with max speed indicators on speedometer for every gear
1st = 21mph, 2nd = 32mph, 3rd = 45mph, 4th = 58mph, 5th = 70mph
Peak Torque 7500 rpm, Peak Power 8500 rpm

2002 km/h version with max speed on speedometer for every gear

Gear km/h mph
1 30 18.6
2 50 31.1
3 70 43.5
4 90 55.9
5 110 68.3
Peak Torque 7000 rpm
Peak Power 8500 rpm

Front Disc Brake model (2005) Test Ride flat out

3rd = 55mph (felt like a rev limiter cut in = 10500 rpm)
4th = 60 / 62mph (downhill, headwind)
5th = 60mph (same headwind, level ground)

The test ride seems to show there is a rev limiter at
10500 rpm. It also shows if the bike had an rpm dial the
red line would start at 9000 rpm and end at 10500 rpm.
9609rpm develops less power and torque than 8160rpm
I expect rev limiter is in the CDI (electronic ignition) box

Front Disc Brake Model (2004 to 2008)

                                       Gear
1 2 3 4 5
mph         rpm
5 2129 1324 978 801 680
10 4258 2648 1957 1602 1360
15 6387 3972 2935 2403 2040
20 8516 5296 3914 3203 2720
25 10645 6620 4892 4004 3401
30   7944 5871 4805 4081
35   9268 6849 5606 4761
40   10593 7828 6407 5441
45     8806 7208 6121
50     9785 8008 6801
55     10763 8809 7481
60       9610 8161
65       10411 8841
70         9521
75         10202
80         10882

                              Gear (% = Gear Gap)
  1 2 3 4 5
rpm 37.8% 26.1% 18.2% 15.1% mph
7000 16.4 26.4 35.8 43.7 51.5
8000 18.8 30.2 40.9 49.9 58.8
9000 21.1 34.0 46.0 56.2 66.2
3500 8.2 13.2 17.9 21.9 25.7
4000 9.4 15.1 20.4 25.0 29.4
4500 10.6 17.0 23.0 28.1 33.1
5000 11.7 18.9 25.5 31.2 36.8
5500 12.9 20.8 28.1 34.3 40.4
6000 14.1 22.7 30.7 37.5 44.1
6500 15.3 24.5 33.2 40.6 47.8
7000 16.4 26.4 35.8 43.7 51.5
7500 17.6 28.3 38.3 46.8 55.1
8000 18.8 30.2 40.9 49.9 58.8
8500 20.0 32.1 43.4 53.1 62.5
9000 21.1 34.0 46.0 56.2 66.2
9500 22.3 35.9 48.5 59.3 69.8
10000 23.5 37.8 51.1 62.4 73.5
10500 24.7 39.7 53.7 65.6 77.2
11000 25.8 41.5 56.2 68.7 80.9

5500 rpm is my advised warming up speed.
It's also the maximum speed I would run a new engine in.
It probably takes 3.5 to 5 miles to warm up, dependant on outside temperature.

I would not go past peak power,
the engines power will dramatically drop off above this
(because it's a pushrod OHV engine, not OHC) and increase engine wear.

If you use the bike above 7000rpm (51mph 5th Gear),
please read all of the Spark Plug page and Which Oil Quality to use in the Servicing page.

Peak Torque = 7000 rpm, Peak Power = 9000 rpm, Generator Full Power = 5000 rpm

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