Author Topic: CB750 rear sprocket fit on CB550?  (Read 359 times)

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Offline Matow123

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CB750 rear sprocket fit on CB550?
« on: January 19, 2023, 11:32:10 AM »
Hello all,
I am trying to do small modifications to my 1973 CB550K. I read under an older Hondaman post that it may be a good idea to add 4 teeth to the rear sprocket to change the rev range and add some acceleration power? Unfortunately I have not been able to source such an object but have noticed that the CB750 new stock sprockets do have 41 teeth. I've seen people put whole wheels from a 750 to a 550, but what about just the sprocket?

Offline bryanj

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Re: CB750 rear sprocket fit on CB550?
« Reply #1 on: January 19, 2023, 11:33:17 AM »
Not to my knowledge
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

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Offline robvangulik

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Re: CB750 rear sprocket fit on CB550?
« Reply #2 on: January 19, 2023, 12:16:50 PM »
You could put a 16 teeth front sprocket on, just to try if you like it, is cheaper too....

Offline Matow123

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Re: CB750 rear sprocket fit on CB550?
« Reply #3 on: January 19, 2023, 04:22:15 PM »
Darn, and would changing the front rather than the rear have a similar effect on the final gearing then? I understand it changes the ratio but would the effect be comparable?

Offline nvr2old

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Re: CB750 rear sprocket fit on CB550?
« Reply #4 on: January 19, 2023, 04:44:08 PM »
Darn, and would changing the front rather than the rear have a similar effect on the final gearing then? I understand it changes the ratio but would the effect be comparable?

You'll notice the same effect.  It'll accelerate quicker, but it also effects the higher speed range, too.  I did the 16 tooth front on my '76 CB550F and liked the change but I also wanted to cruise easier at 65-80mph, so I went back to stock front and rear sprockets.  The bike was happier that way.
'76 CB550F-'72 XL250-'82 MB5-'82 CX500 Turbo-'77 naked Goldwing-'75 CB400F cafe'-'79 Suzuki GS1000S..hey, it's a Wes Cooley..

Offline BenelliSEI

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Re: CB750 rear sprocket fit on CB550?
« Reply #5 on: January 19, 2023, 05:18:46 PM »
I’m pretty sure I used a few different cb750 sprockets (1969-76) on my 1978 cb550K. Not sure about your earlier cb550, but the later bikes used the same brake/drive hub in the 18” rear wheel. Lookup on line, I think JT Sprockets often post drawings of each sprocket theyoffer, including bolt hole sizes and bolt circle diameters. Measure yours up and compare.
« Last Edit: January 20, 2023, 05:39:15 AM by BenelliSEI »

Offline scottly

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Re: CB750 rear sprocket fit on CB550?
« Reply #6 on: January 19, 2023, 05:53:08 PM »
Hello all,
but have noticed that the CB750 new stock sprockets do have 41 teeth.
The 41 tooth sprockets fit the K7/K8 750 models, which used a 630 size chain instead of a 530 chain like most 750s, as well as 550s. The standard 750 rear sprocket is 48 teeth.
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Offline dave500

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Re: CB750 rear sprocket fit on CB550?
« Reply #7 on: January 19, 2023, 11:08:24 PM »
leave it as it is believe you me!if you gear it down any youll be chasing another gear thinking its stuck in 3rd or 4th no #$%*!if your track racing it yeah but on the road in real life i think Honda got these smaller bikes gearing pretty well spot on,ive toyed with the gearing on these and stock is perfect to me.

Offline dave500

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Re: CB750 rear sprocket fit on CB550?
« Reply #8 on: January 19, 2023, 11:18:12 PM »
just out of interest the 500 had 17x34,the 550 17x37 but retained the same overall final drive by the 550 having a taller primary reduction,the idea was to drive the transmission and clutch faster giving better selection plus a few other changes in the transmission,i once tried a 37 rear on a 500 and got two blocks then went straight home and swapped it back,and i live in a hill n dale area!