The International CBX Owners Association

chavcat wrote:Hi-Falicon in the past limited the stroke to 5mm (thay recommended 2-4mm for longevity).

The limitation you may run into is not the rods and the crank, but may be piston/ring problems. If Falicon recommends these numbers particularly for the CBX, the maximum stroke would be around 58-59mm. This will give you a mean piston speed of close to 20m/sec at 10,000 rpm, and I can see why Falicon would say that 2-4mm should be the ideal for longevity. Long stroke motors are usually not high rev units.

I think a speed of 20-25m/sec should still be acceptable for motorcycle pistons. The long 6-cylinder crank and the oscillation and bending would concern me more, though.

EMS wrote:

chavcat wrote:Hi-Falicon in the past limited the stroke to 5mm (thay recommended 2-4mm for longevity).

The limitation you may run into is not the rods and the crank, but may be piston/ring problems. If Falicon recommends these numbers particularly for the CBX, the maximum stroke would be around 58-59mm. This will give you a mean piston speed of close to 20m/sec at 10,000 rpm, and I can see why Falicon would say that 2-4mm should be the ideal for longevity. Long stroke motors are usually not high rev units.

...hello the 750 F has a 62mm stroke!! 900-1100F has a 69mm stroke!! why should a CBX stay below 60mm???...not because of piston speed.....chuck

They have longer rods then the CBX. Rod length effects piston speed, piston acceleration, and lateral forces on the piston.

HI............I can use either a 750 or a 900 deck height & either rod size(will be using a 17mm pin size for 1100 overbore pistons).....chuck

chuck_b24 wrote:HI............I can use either a 750 or a 900 deck height & either rod size(will be using a 17mm pin size for 1100 overbore pistons).....chuck

Keep us updated on your progress. You are working on a very interesting project.