Redline and gear speeds.

4getful2 said:

I wonder what the rpms are at say 65mph with the stock drive verses the c90 drive ?

Click to expand...

At 65mph, the C50 is turning ~ 4100 rpm in 5th gear with the stock gearing.
At 65mph, the C50 is turning ~ 3650 rpm in 5th gear with the C90 drive.

It is enough to tell a difference in the way the engine sounds and feels, but it is still buzzy and feels like it needs another gear.

The C50 will top out somewhere between 90 and 95 mph (actual). The speedo is a bit optimistic and will tell you you're doing the ton, when you're really almost 10mph slower...

It is a fine mid sized cruiser, but it is not quick nor is it intended for long stretches at interstate speeds (70mph and above)

90kph, sure. 90mph? Not possible.

At 90mph, your engine is running between 5600 and 6300 rpm. 2001-2004 VL800s used a dual fire ignition, meaning both coils fired at the same time. From 2005 on, the C50 uses a single fire ignition, meaning only the cylinder at TDC of the compression stroke is firing. If your tach is only showing 3k rpm, then you have the wrong tach on the bike. That is expecting a dual fire ignition, but only reading single fire - which is HALF of what the engine is turning in RPM. Sorry to burst your bubble.

Nobody modified the drivetrain. This little engine doesn't have the gonads to turn 3k RPM at 90mph. Sorry. You're actually running it up close to its redline of 7250rpm.

LOL. Sure it does. We all have the same bike. You're at the end of WOT at 90 my friend. You cannot change the laws of physics.

A bike with the modified C90 drive will have obvious machine marks where the old shock mount was ground off, or to make the fake swing arm fit. Other than that, the only way would be to pull the drive and look for the tell tales - shortened driveshaft modified shoulders on the end, etc.

The C90 drive only lowers the rpm by around 10% at a given speed. It makes things more comfortable, but it doesn't eliminate the vibrations.