Topic: Sprocket talk

[KrautKoffin]

I'm replacing my sprocket and chain in the coming days and was looking for some advice. The PO graciously gave me a bin of new parts he planned on putting on the bike but never got around to, and a new 630 chain was in bottom, still nicely wrapped and gold (looks cool he said). I was looking at sprockets and am utterly (and easily) confused. I know I need a 630 front sprocket, but how many teeth? I'm looking to just replace the stock OE unit and not change the gearing if possible. Do you gurus recommend any brands in particular, and why them? Some tips on buying and or installing would be extremely appreciated! I read the threads google offered and 90% of what I found was Frank saying to take a blank sprocket in to get it machined or people doing a 530 swap.

[Jerry Rxman Griffin aka MuthaF'er]

I think you've told us everything EXCEPT what bike you are referring to and how many links your new pretty chain is!

[goldarrow]

I think you've told us everything EXCEPT what bike you are referring to and how many links your new pretty chain is!

And that's the key

[Cqyqte]

If you follow the link on the bottom of his post, it says he wants to buy a part for a CB450!  Maybe this is a contest or challenge?

[KrautKoffin]

If you follow the link on the bottom of his post, it says he wants to buy a part for a CB450!  Maybe this is a contest or challenge?

Hahahah late night last night.. 77 cb750k.

[TwoTired]

If you follow the link on the bottom of his post, it says he wants to buy a part for a CB450!  Maybe this is a contest or challenge?

Hahahah late night last night.. 77 cb750k.

Shop manual says the front is a 15T and the rear 41T for the K7.

[754]

So do you have any 630 sprockets right now?

[KrautKoffin]

So do you have any 630 sprockets right now?

Yea, they are on the bike now. I'd like to replace them with new ones.

Frank, did you get that plug mailed?

[754]

Yes i believe i PM,d stating that..

[750K]

I'd count the teeth on what you already have on the bike if you don't want to change the existing gearing, 15t f and 41t r are as TT said the stock sizes for the 630 sprockets on a 77-78k. If you want more jam off the line and do more in city riding drop the front to a 14t, you'll be in higher rpm's on the highway though.

Check JT sprockets online, they show what's available in the 630 sizes and give gearing ratios, pretty limited in the 630 sizes but you have more options going to 530. Although seeing as you have a chain you already have the most expensive part of the equation, sprockets are cheap compared to chains.

[zeech]

Here's a quick sprocket ratio chart I made up while deciding what to go with as well as I'm swapping out my 630 for a 530 and will need new sprockets and chain.

14/41 = 2.93
15/41 = 2.73 — Stock Ratio
16/41 = 2.56
17/41 = 2.41
18/41 = 2.28

14/48 = 3.42
15/48 = 3.20
16/48 = 3.00
17/48 = 2.82
18/48 = 2.66 — Stock Ratio

14/43 = 3.07
15/43 = 2.86
16/43 = 2.69
17/43 = 2.53
18/43 = 2.39

[lucky]

I'm replacing my sprocket and chain in the coming days and was looking for some advice. The PO graciously gave me a bin of new parts he planned on putting on the bike but never got around to, and a new 630 chain was in bottom, still nicely wrapped and gold (looks cool he said). I was looking at sprockets and am utterly (and easily) confused. I know I need a 630 front sprocket, but how many teeth? I'm looking to just replace the stock OE unit and not change the gearing if possible. Do you gurus recommend any brands in particular, and why them? Some tips on buying and or installing would be extremely appreciated! I read the threads google offered and 90% of what I found was Frank saying to take a blank sprocket in to get it machined or people doing a 530 swap.

I would not use that big a$$ heavy #630 chain unless you want a hole in your engine case.

 Hang it on the wall for decoration or something.
Make bracelets out of it.
A #530 chain is more than enough.
Cycle-x uses a #520 chain and sprockets on their CB750 race bike.

[TwoTired]

I would not use that big a$$ heavy #630 chain unless you want a hole in your engine case.

LOL  Gotta love internet unsubstantiated speculation.

That is exactly what Honda was preventing with the bigger chain.  I've never seen a 630 chain break on the CB750 even when severely abused.  But, lots of cases were broken with the 70s era 530 chains on the cb750.  Arguable if they were abused, as the owners would seldom admit to that.  Then there is that battery overflow drain dripping acid on the chain. 

[750K]

Are you retarded lucky? I'd like to see you break a modern 630 chain on a cb750, highly doubt it will happen...

[BobbyR]

I think you would do well to keep your 630 chain and stock gearing. If you are just running around Town find a gear that keeps you around 3K on local streets. This gives you good engine braking and plenty of jump.

When you get out on the open road the stock gearing gives you passing power and it is not buzzy.

Lucky must have been using brake cleaner in a small space tonight. 

[Stev-o]

+1 JT Sprockets.....


http://www.ebay.com/itm/JT-Sprockets-Steel-Front-Sprocket-14T-JTF331-14-Honda-CB750K-77-78-/350613550604?pt=Motorcycles_Parts_Accessories&fits=Model%3ACB750&hash=item51a232360c&vxp=mtr

[KrautKoffin]

So we've deduced that lucky doesn't take the proper meds, and JT sprockets are the way to go. I'll see if that same seller has a rear sprocket. 41 teeth for the rear?

I decided on going with the 14 tooth front sprocket because this bike will rarely see highway speeds.the downfall of living in Southern California is the traffic, and unfortunately I'll be in the thick of it.

[Black 750K8]

My  78 750K had a 14 when I got it and I just put a new 630 setup on it 15/41 I did not feel a big difference when I am in the city. I keep it in 2nd maybe 3rd. It does feel more relaxed on the open road and that is what I was after. DSS has them to compare price.

Lucky never has liked the 630 I don't know why. But there is no way in hell my stock motor is going to break my chain.

[750K]

So we've deduced that lucky doesn't take the proper meds, and JT sprockets are the way to go. I'll see if that same seller has a rear sprocket. 41 teeth for the

Hahaha, lol on the meds.

I really liked the 14t around town, it felt good to stomp people into the dirt at a green light :$ I spend equal amounts of time on the highway as I do in the city so the stock setup made more sense for me. I recently picked up a cycle-x 520 sprocket set and will swap out the heavy 630 chain when ever it's worn out or I happen across a good deal on a high tensile 520 chain.

[70CB750]

My F motor (F as supersport, not F as fcuking motor and rear wheel came with 530 sprocket(s) and I see no reason to change back to 630. 

Time to lay off the brake kleener