Topic: cb750 rear sprocket

[jreich]

I'm trying to determine the year 750 that this rear sprocket came off of, so that I can buy a 37t. This one is a 48t.

The distance from hole to hole is 3 1/8" center to center.



There may a an easier way to determine what year hub this is, so if there is, I'm all ears.

Thanks in advance.

JD

[Gordon]

The bolt holes on my K1 sprocket measure the same as that one, so any sprocket made for a 750 up through K6 should work. 

Just curious, why such a big change in gearing? 

[jreich]

I am using a 750 rear hub laced to a 16" rim on my cb550 build.

My old gearing was 16t up front and 37t on the old 550 hub in the rear.

Would using a 37t 750 rear sprocket equate with using a 37t 550 rear sprocket?


Is the width of the 550 and 750 rear sprockets the same, so that I can use the same old stock 550 chain?

whew...thanks for the help

JD

[Gordon]

Yes, the sprocket width is the same because both bikes use a 530 chain.  Have you checked the difference between the hub widths? 

[jreich]

Thanks so much Gordon...I greatly appreciate it

I never did measure the difference in hub width between the 550 and 750.

I am using this on a hardtail that I bent up and welded on, and therefore fabricated spacers to accommodate this specific hub and to achieve the correct chainline.

Thanks again for the help Gordon

Cheers
JD

[Gordon]

Cool!  Pictures will be required when you're finished!   (or even before you're finished)

[jreich]

Here are a few pictures of where I was at a few weeks ago....

http://forums.sohc4.net/index.php?topic=36458.0

Haven't had much time to take pictures in the meantime, but have handrolled a fake oiltank to house the electrics, and done a number of other things.

It is really amazing how much goes into a ground up build....as this is my first, I'm learning what works (and what doesn't) for next time.

Speaking of next projects...I just picked up a '63 Triumph TR6SS engine that I will be working on, and building up over the winter

So, I should quit rambling as I just took this thread from sprocket identification to Triumphs....

thanks again Gordon...much appreciated.

JD