Topic: chain and sprockets

[WilliamA]

Gentlemen,
I know this subject has been beat to death but here goes.
I want to replace the sprockets and chain on my 1978 CB750K.
as I understand it the 530 x-ring chain is the best and is strong enough for the motor size.
I get lost on the sprocket sizes versus the rpms and who I can purchase from that is knowledgable.
Heeeeeeeeeeeeeeeeeeeeeeeeeeeelp!

[GammaFlat]

78 CB750's came with a 630 O-Ring.  It's easier to find a front sprocket that is 630 for your setup.  You should have a single bolt in the center of the front sprocket.  Assuming your engine is a '78, it does not have an "automatic oiler".  I hear that X-Ring chains are a lot more expensive than O-Ring chains. 

Your choice, but your easiest path is stay 630 due to the way the front sprocket mounts.  Some folks here have mounted up a 530 front sprocket on 77 and 78 bikes.  The shoulder of the 530 sprocket is wider at it's base.  The 530 sprocket in the front will therefor not become flush to the end of the final shaft when you bolt it down.  530 (76 and prior) front sprockets normally mount with 2 bolts and a slotted retainer and are engineered to float a little on the final shaft.  Most of the 76 and prior engines have provisions to "auto-oil" the chain. 

[MCRider]

Along with whjat gamma has said, if you are looking to convert your 630 to a 530, there may be alignment issues with the sprockets. You'll need to get a 530 rear sprocket and a sprocket carrier from an earlier bike, or something like that. I am more alerting you to the problem than giving the details on how to do it, as i don't know for sure.

Sticking with the 630 is the easiest. If it were mine I'd switch to the 530, less rotating weight, and modern 530s are more than up to the challenge. But there are issues.

[ksmith0034]

I don't know if this help you, but I just ordered DIA XMC-1548-M-102P
530 RIV 102P
from kscdirect.com for $53.70 incl shipping.  I also ordered 17 and a 48 tooth 530 sprockets from Z1 Enterprises.

[GammaFlat]

I don't know if this help you, but I just ordered DIA XMC-1548-M-102P
530 RIV 102P
from kscdirect.com for $53.70 incl shipping.  I also ordered 17 and a 48 tooth 530 sprockets from Z1 Enterprises.

That stuff will fit a 77/78 bike with some caveats.  The front sprocket mounts "other than intended from the factory".  Is it okay to mount the 530 sprocket on a K7/K8 engine?  As mentioned, folks here have done it.  The swing arm on a K7/K8 is a bit longer and a 102 link chain may be "testing" how far forward you can move your rear wheel.  I believe it will fit.   

I don't believe there to be any alignment issues if you put 530 sprockets on a K7/K8.  Alignment issues come into play when you put a K7/K8 engine in a K6 or prior bike or vice versa.  The sprocket on the engine on K7/K8 engines is 10mm more outboard than K6 and prior.  A K7/K8 swing arm and wheel setup correspondingly moves the sprocket out 10mm (it's in the carrier).  There are goofy sprockets available to "adjust" the chain inward or outward by the 10mm difference but I'd try real hard not to go there. 

Having said all that, I'm with MCRider, I'd go 530 as well.  Also, that chain that ksmith got is an excellent chain (I own one). 

[Skunk Stripe]

If you get the right sprockets, you do not need any carrier or any other goofy thing from an earlier bike.
When I went 530, I got a 6 spline front sprocket and a standard rear and it bolted in just fine and aligns just fine too.
wax on, wax off. it was that easy. Maybe I have been lucky but it has been like this for 4 years or something like that with no issues of any sort.