Speed/RPM Question

[jagans]

Hi Guys,

I just finished getting my 1980CB 650c running well, but something is bugging me. I really feels like it needs at least another gear. In 5th, I am turning around 3,000 RPM at 45mph. Is this normal? Can anyone tell me about what the correct RPM/MPH should be for each gear? Like what RPM should she be turning at 60MPH in 5th?

Thank You, I really appreciate it.

[my79650]

I can tell you with a 100/90-19 front and a 130/90-17 rear at 50 mph it shows 4000 rpm. its round 4300 rpm with a 16 inch rear which i am running now. Depends on your tire/rim size and sprockets. Are you running with stock front and rear sets? If you change the size for the front 1 tooth up or down it will change your power curve.

[cb650]

My 81 standard is hi on the rpms also. its designed like that. Seems hi unless its a track or city only bike. Change to what you like.

[MiGhost]

@ 60 mph I am turning just over 4700 rpm using 17/39 sprockets.
You will find the bike more responsive in the higher rpms range.

Ghost

[jagans]

Thanks very much guys. I appreciate your responses without my stating what sprockets, tire/ rim size I am running. I am pretty sure everything is stock. I guess I just have to get used to the high RPM's or change sprockets. I find it really weird that they geared this bike so low with an engine that produces over 60 hp. I had a Hawk (390cc) that only developed 19+ HP and it did not feel like it was winding up like this bike.

The RPM's you all describe sound right, and I thank you all for your efforts.

JimA

[cb650]

Then why didnt you count and post what sprockets you have????
There are a few diff models and over 30 years who knows what has been put ob "YOUR" bike. I was just trying to give a general guideline to a general question.

[jagans]

Darn good point. Ill do it and post what I have. Maybe some of you have a combo that works good for you. Im about 250lbs, so I need more power than speed, but maybe I can hit a happy medium. Maybe I need a bigger cruiser

[my79650]

These old inline 4 engines were made to produce the power at hi revs, Despite that they are pretty reliable and plenty powerful depending on how you drive it....its all a personal preference on how you drive. Any tweaking is for personal gain. Mine is stock for gas mileage and cruising from 50 to 60 mph on the rural roads; i don't do too much hiway driving.