Topic: Front Drive sprockets and Partsnmore

[rivetslag]

As of today, at parts-unlimited.com  http://www.parts-unlimited.com/fitment/searchParts.do
You can get either 630 or 530 front and rear sprockets. You can probably find them on other sites too.
I found the parts unlimited catalog on mawonline.com

I see two 15T 630 front sprockets for a K7, but no 530 front sprockets. Nothing at all for K8s, although obviously that's because of the 77-78 identity.

[CB750Ken8]

  Cry, and my rear sprocket and chain are 530..... Grrr i suck at making the right decisions and choosing the right parts.

[zzpete]

Cry, and my rear sprocket and chain are 530..... Grrr i suck at making the right decisions and choosing the right parts.

Here is a 530 conversion kit on ebay for your bike
http://cgi.ebay.com/ebaymotors/530-Conversion-Chain-Sprocket-Honda-CB750K-77-78-18-38T-_W0QQcmdZViewItemQQhashZitem4cf053aedbQQitemZ330449530587QQptZMotorcyclesQ5fPartsQ5fAccessories#ht_1955wt_808

[CB750Ken8]

Thanks for the find Pete, I'm just complaining because I'm not into the idea of spending more money  on something I already bought, I could TRY and return the stuff since I have had it for year, I think most places have a 30day return policy.

[zzpete]

Thanks for the find Pete, I'm just complaining because I'm not into the idea of spending more money  on something I already bought, I could TRY and return the stuff since I have had it for year, I think most places have a 30day return policy.

Sorry to hear that. Put them in the Bikes & Parts For Sale section.
http://forums.sohc4.net/index.php?board=34.0
But first let me get this straight, you have a 530 chain and rear sprocket (that fits your bike). If thats true you just need a 530 front sprocket (that fits a 1978 CB750 K)....right?

[CB750Ken8]

I don't know if it will fit or not I just know I ordered it the chain and the front sprocket at the same time, I double checked my old chain and sprocket against the new chain and sprockets.

The old chain had 630 stamped on the links, and meshed with the old sprockets fine, but wouldn't mesh with the new sprockets at all, then I tried the new chain which meshed perfectly with the sprockets I had ordered, but was too small of a pitch to mesh with the old front sprocket. If I could ever get the wheels off the bike and maybe do a test to see if the new rear sprocket fits and aligns then I could give a definitive answer.



Edit: I just got the message back from the guy on ebay I got the newer front sprocket from and he says its for a 530 chain, now just get to see if partsnmore is correct about the rear sprocket being for a '78 CB750 K8.

[CB750Ken8]

Update, The rear sprocket fits onto the rear wheel just fine, and the front sprocket came in...the guys is either misinformed or did not bother to check for actual fitment...its a 630 sprocket.....and I was so pumped up about being able to ride around this weekend and to work on Monday. 

[zzpete]

Update, The rear sprocket fits onto the rear wheel just fine, and the front sprocket came in...the guys is either misinformed or did not bother to check for actual fitment...its a 630 sprocket.....and I was so pumped up about being able to ride around this weekend and to work on Monday. 

O.k. you have a 530 chain and rear sprocket. Return the 630 front sprocket and get a 530
The following link discusses a 530 chain conversion on a 1978 CB750. Focusing on the front sprocket. Looks like some good info.
http://forums.sohc4.net/index.php?topic=2743.0

[CB750Ken8]

Thanks for that informative link zz, and yes I'm working on replacing both front sprockets the one off ebay I'm gonna send back to the guy if he'll let me (should I've got 7 days to return it) and I'm talking with Partsnmore now that I've found the old invoice and talked to their tech department about the sprocket fitment issues, now lets just hope they will let me send it back and get a different one, I'm going crazy not being able to ride my bike in this nice weather, especial now that I now it runs and I'm only missing a slight carb tune up and syncing and installing hte drive chain and front sprocket!

[zzpete]

Sounds like your so close you can taste it! Get the carbs set and the rest all ready to go so the day the sprocket comes you can put it on and go!!!! That is, if the weather holds.

[rivetslag]

I just noticed an available 530 conversion front sprocket on this site: Mavrik-Powersports. I think the place is owned by another SOHC4 member here. There is a 77-78K 530 sprocket at the very bottom of the list.

17 and 18 tooth available...18/48 puts you at the closest possible final ratio to stock. I chose 17/48, it makes a very enjoyable boost in acceleration, but puts you closer to 5k rpm when cruising (5k rpm @ 70 mph indicated on my bike).

[cb750k7]

Hi CB750Ken8
I had the same issue like .
My bike is a K8 with a K6 motor.

One of the PO had installed the 530 chain and sprockets,  and when I wanted to change the outfit, I had ordered the Diamond chain and JT sprockets.

I wanted to improve the fuel consumption,  so I went to change the front sprocket by one tooth,  guess what?  I ordered 16 instead of 18.....
The bike was never so responsive and zappy but the fuel consumption....

So a new order for a 18 teeth  was placed,  but the chain was now too short!
The 530 chain 102 links is not long enough for a K8,  you need 104 links !!!!!

Facing this,  and the fact that Diamond is not shipping overseas the 2 missing links,  I had to buy a new chain,  this time an RK  O-Ring with 104 links,  planning to get the missing links in the future and put the Diamond back.

Some insight from my latest ordeals,  the 16/48 ratio had me on 4700 rpm at 60 Mph,
the 18/48  is about 3950rpm at 60 Mph.  I hadn't check the fuel consumption yet, (fresh from last night) but when I'll have info I'll put it here.

I have installed Pampadori's new SS brake hose and sure enough,  it feels better already.  TNX Pampadori.

BTW,  I am going to meet Medic09 next friday in Jerusalem,  so I guess we will have a lot to talk about our K8...


Cheers,

Jona

[rivetslag]

So a new order for a 18 teeth  was placed,  but the chain was now too short!
The 530 chain 102 links is not long enough for a K8,  you need 104 links !!!!!

I can confirm that you'll need 104 links. I got a 110 link EK standard chain to be safe, had to take off 6 links, I believe.

[CB750Ken8]

Yeah, I have an Izumi 110 link 530 chain.

[CB750Ken8]

So for an update....I got the new front sprocket on Sat to only find out its a 630 pitch, messaged the guy I got it off of and he refunded (great ebay seller), so now I'm back to trying to find JUST a front 530 chain sprocket, Rivetslag I tried that link to mavrik but got a web error. Now I'm almost wondering if I can find somewhere or way to get a 530 sprocket made just so I don't have to buy an entire kit since  have 2/3 the stuff already.

I checked out bike bandit, but the only aftermarket ones they have are all the wrong spline, what in the world is with every place that has just the front sprocket for a ""'77-78 750 K"" all have the wrong sprocket?

Either way I have half a notion to try and get a custom sprocket made up, maybe cut the spline out of the old front sprocket and new 530 sprocket and have them welded together, or get one made up....sorry for the ranting, I just want to ride and 1 stupid piece that costs about $20 is holding me up.

[rivetslag]

You should maybe re-read the suggestions made in this thread before you do something crazy like that. That link to mavrik-powersports a couple posts up indicates a proper 530 front sprocket for 77-78 CB750K. My front sprocket thread from an earlier post in this thread lists the part number for a JT front sprocket, for a 530 chain, that does fit on 77-78 K bikes. I use this sprocket right now (after having milled off the shoulders). This JT sprocket is also listed in the Chain and Sprocket FAQ, the guy there did not mill the shoulders off. So as I see it, you have at least three options already suggested here. The JT sprocket can be ordered from any Parts Unlimited local dealer or website, or any other place that carries JT.

To reiterate: if you want a 530 chain setup, you need a front/rear combination of 17/48 or 18/48 sprockets, and a 104+ link chain. The rear is easy to come by, the front is scarce but it IS around.