Chain mismatch help

[RedSchmutz]

Hey all,

I am in the middle of a build, everything stripped and undergoing machining and painting, but I have realized that I have overlooked what should have been obvious to a more experienced mechanic. But, as this is my first build and I take one step back for every step forward, I came seeking help from the sages of the internet. My situation is this; I have a 77' CB750F engine and frame that I am pairing to an 08' Yamaha R6 rear swing arm. I am fabricating the necessary frame to align the swing arm and mono-shock. However, when I checked my original chain against the R6 sprocket, it wont seat. I have read that I can drill holes in a stock cb750 rear sprocket in order to mount it to the R6 rear wheel. However, with the additional power resulting from my boring the engine to 832cc, I was hoping to keep the larger R6 rear sprocket to prevent too much torque to the rear wheel and creating a bike that is prone to rear wheel spin. Should I explore a new drive sprocket? I am kind of at a loss as to where to go from here. So, suggestions anyone? Has anyone else already come to some suitable solution? I look forward to your suggestions.

 

[dan1951]

Hey Red, I,m not real keen on Your situation but a larger rear sprocket will give You more torque and power to the rear wheel, Smaller on the rear will give less and a higher top end speed, A 48 tooth rear would be in the ballpark, Sorry I could not be of more help. Good luck with Your project.

 

[dirtdigger]

Dan is correct, the bigger the rear sprocket the more torque you will have to the rear and the more prone it will be to wheel spin. The r6 is probably a 520 chain where the 750 is a 530. You will have to decide what you want to do as far as gearing. There are 520 sprockets available for the 750 if you want to keep the r6 sprocket.

 

[RedSchmutz]

There are 520 sprockets available for the 750 if you want to keep the r6 sprocket.

At this point, my main point of concern is getting the front sprocket in order while I have the engine torn apart. I'll adjust the rear sprocket as necessary once I see how it rides and how the power feels. Thanks for the help, turns out it is a much, much more simple resolution than I feared, but it was the one I hoped for.

 

[RedSchmutz]

Any recommendations where to purchase a 520 front sprocket?

 

[RedSchmutz]

EDIT: As I have looked it up, as far as I can tell, the Yamaha used a 525# O-ring chain. So I will need to find a directly compatible front sprocket. I may need to adjust the rear sprocket as well after all.

 

[kdesmo996]

Hello sorry to steal your thread but im in the same dilemma.
Where can I find a 525 front sprocket?

Thanks