Topic: Sprocket set on k7 is 41/15 with stock 630 chain. Need a new chain for next season, should I upgrade

[Pielz]

Curious about what would really make a difference. My sprocket set looks great. There's not a noticeable amount of wear on the teeth so I don't think they really NEED replaced. I'm wondering though if I should go with a 530 chain as I've heard good things about their strength and benefits. Any opinions? I've seen threads about this but none on my model with the smaller sprocket sets. I wouldn't mind a little snappier low-end power as I'm not going to be using the upper limits of this thing's speed.

[slikwilli420]

Modern 530 chains are found on all of the most powerful bikes put on the road today. A 530 kit with aluminum rear sprocket will reduce overall weight of that system considerably and will likely cost less for better quality than finding 630 components. If its time to change, there is absolutely no downside to going 530.

[Pielz]

Awesome good to know! Is there a site that sells kits for our bikes that have everything? Or should I just verify fitment and get things separately? I'm making a little list of things I need to get in the future before it warms up again

[mrbreeze]

Another reason to change over to 530 is the availability of 630 components on the road. Roughly 10 years ago while doing the SOHC rally, a member that we were riding with encountered a stretched out chain that couldn't wait to be replaced when we got back home. After trying a handful of local shops to no avail, we found a 630 chain but it was roughly 50 miles out of our way to go get it. Not that we minded the extra riding we got in to go fetch the new chain it still could have cost a lot of headaches if the chain wasn't available. If I remember correctly all of the other shops had the 530 in stock.

[Pielz]

Wow that's a really great point. I hadn't actually thought of that. Btw how much do you typically spend on a chain? I've heard people talking about a few different brands and o ring or x ring. Not sure what to get!

[pjlogue]

When I restored my '76 750 I went with a 530 set up.  I had looked for a 630 set up like I had but I could not find the  sprocket combos I wanted in that size so I went with the 530. 

-P.

[ekpent]

When I restored my '76 750 I went with a 530 set up.  I had looked for a 630 set up like I had but I could not find the  sprocket combos I wanted in that size so I went with the 530. 

-P.

Hmm- no 630's in 1976 on either the K's or F's.

[evinrude7]

When I restored my '76 750 I went with a 530 set up.  I had looked for a 630 set up like I had but I could not find the  sprocket combos I wanted in that size so I went with the 530. 

-P.

Hmm- no 630's in 1976 on either the K's or F's.

that threw me for a loop too. 

Modern 530 chains are found on all of the most powerful bikes put on the road today. A 530 kit with aluminum rear sprocket will reduce overall weight of that system considerably and will likely cost less for better quality than finding 630 components. If its time to change, there is absolutely no downside to going 530.

any recommendation on the aluminum rear sprocket?  seems like a soft metal to me for a sprocket.

[Pielz]

So I'm searching the internet and I can only find 15 tooth or 14 tooth gears in 630 and 17 tooth and 18t in 530. In order to get the final drive ratio that's higher than my current id have to get like 17/51 and I definitely can't find rear sprockets with that many teeth. I may get a 14/43 or 15/46 and stay with 630. As much as I'd like a 530 lighter chain I can't seem to find what I need unless I'm just looking in the wrong place

[Dolomite]

Awesome good to know! Is there a site that sells kits for our bikes that have everything? Or should I just verify fitment and get things separately? I'm making a little list of things I need to get in the future before it warms up again

Cyclex sells the offset from sprocket for the 530 chain and I got my rear from JT. I'm running a JT 530  Z3 x ring chain. Working great so far.

[Pielz]

So is the offset front sprocket for only certain bikes or is it offset to accommodate the smaller chain? I saw that but was nervous about it because I hadn't heard anyone mention those. what teeth #s are you using? What's your final drive ratio? Also what model bike?

I was hoping to bump my ratio up to 3 from the 2.7 it is for a little boost but I'm not sure what all is available.

[1976cb750f836]

Defiantly do the small chain conversion. Less rotating mass, less unsprung weight, a tad more power, and mpg. No negitive.

[pjlogue]

When I restored my '76 750 I went with a 530 set up.  I had looked for a 630 set up like I had but I could not find the  sprocket combos I wanted in that size so I went with the 530. 

-P.

Hmm- no 630's in 1976 on either the K's or F's.

that threw me for a loop too. 

Modern 530 chains are found on all of the most powerful bikes put on the road today. A 530 kit with aluminum rear sprocket will reduce overall weight of that system considerably and will likely cost less for better quality than finding 630 components. If its time to change, there is absolutely no downside to going 530.

any recommendation on the aluminum rear sprocket?  seems like a soft metal to me for a sprocket.

I had put the 630 on in 1977 or 78.  When I went to the 630 chain I put  JT Aluminum sprocket on the rear.  I think I had a 38 tooth rear (maybe 42) sprocket and 15 T front.  The diamond chain I had was a plain chain but very good quality and had very little power loss though it.  I was skeptical of the Aluminum rear sprocket but it did hold up well and because it was soft the road grit didn't chew up the chain.  I did take care of the chain though with regular cleaning and lubing.

-P. 

[slikwilli420]

A number of places sell a nice 530 aluminum sprocket for our bikes. I run 520 on my race bike so I won't be much help there. I do run a DID X-ring chain though and it was under $70. Should last thousands of miles with little maintenance.

[Dolomite]

So is the offset front sprocket for only certain bikes or is it offset to accommodate the smaller chain? I saw that but was nervous about it because I hadn't heard anyone mention those. what teeth #s are you using? What's your final drive ratio? Also what model bike?

I was hoping to bump my ratio up to 3 from the 2.7 it is for a little boost but I'm not sure what all is available.

I am at work right now but I am trying to find those numbers for you. I believe i stuck with the stock number of teeth though so as to not change anything but the chain. The front offset if i remember correctly is for running the 530 on pre 77 motors because they had the spacer as part of the sprocket while the 77/78 had the proper offset machined into the spline. If someone could confirm or deny that?

[maxheadflow]

I used a 79 cb650 front sprocket on my 78 CB750.  It fit perfect.   Rear sprocket only needs to be flat.

[Pielz]

Is it offset? And are you using 530 or 630 chain?

[maxheadflow]

The back side is flat, no offset. It was recommended here.

I used a PBI Steel Front Sprocket 15T 348-15 off of ebay but you can get other teeth counts.

[Tracksnblades1]

Modern 530 chains are found on all of the most powerful bikes put on the road today. A 530 kit with aluminum rear sprocket will reduce overall weight of that system considerably and will likely cost less for better quality than finding 630 components. If its time to change, there is absolutely no downside to going 530.

Silk,

Have you ran an aluminum sprocket on yours for any length....

I've got a 01 CR500R with expensive 48t 520 aluminum sprocket on back with a rototiller knobby.
The Regina 520 chain (huge overkill never needs adjusted) will lay the teeth forward in no time...

Worst thing about CR500, only 5 gears....Best thing about CR500, what ever gear your in, that's the right gear...😎

[slikwilli420]

Modern 530 chains are found on all of the most powerful bikes put on the road today. A 530 kit with aluminum rear sprocket will reduce overall weight of that system considerably and will likely cost less for better quality than finding 630 components. If its time to change, there is absolutely no downside to going 530.

Silk,

Have you ran an aluminum sprocket on yours for any length....

I've got a 01 CR500R with expensive 48t 520 aluminum sprocket on back with a rototiller knobby.
The Regina 520 chain (huge overkill never needs adjusted) will lay the teeth forward in no time...

Worst thing about CR500, only 5 gears....Best thing about CR500, what ever gear your in, that's the right gear...😎

I roadrace with aluminium sprockets and notice very little wear if any. Granted I'm not eating up miles like road riders but I'm hard on them every second the bike is running. Plenty of far more powerful bikes running aluminium sprockets.

[Erny]

Not long time ago I checked options with for K7 going from 630 to 530 chain. Primary reason was my friend who has K7 with chain to be replaced and secondary to prepare my replacement for the future.

Stock 630 (88 links) has 15/41 ratio, front sprocket has flange on outside rear is flat.
References from JT catalogue are JTF331 http://www.jtsprockets.com/catalogue/sprocket/JTF331/ and JTF333 http://www.jtsprockets.com/catalogue/sprocket/JTR333/
Calculated centers distance 566mm

practically 1:1 equivalent in terms of ratio, spockets centers distance is 530 chain (102 links) 16/43, front JTF338 http://www.jtsprockets.com/catalogue/sprocket/JTF338/, rear JTR284 http://www.jtsprockets.com/catalogue/sprocket/JTR284/. Calculated distance 571mm.

[Pielz]

Not long time ago I checked options with for K7 going from 630 to 530 chain. Primary reason was my friend who has K7 with chain to be replaced and secondary to prepare my replacement for the future.

Stock 630 (88 links) has 15/41 ratio, front sprocket has flange on outside rear is flat.
References from JT catalogue are JTF331 http://www.jtsprockets.com/catalogue/sprocket/JTF331/ and JTF333 http://www.jtsprockets.com/catalogue/sprocket/JTR333/
Calculated centers distance 566mm

practically 1:1 equivalent in terms of ratio, spockets centers distance is 530 chain (102 links) 16/43, front JTF338 http://www.jtsprockets.com/catalogue/sprocket/JTF338/, rear JTR284 http://www.jtsprockets.com/catalogue/sprocket/JTR284/. Calculated distance 571mm.

Thank you for the info!! That's super super helpful. So I see the 530 options have the 2 bolt mounting system. I'm guessing that won't matter?
 
Also the 530 option, the 16/43 gives me a final drive ratio that's less than my current. Won't that make the bike feel a little less snappy on the low end? Or does that not matter as much as I think it does? Id like to raise it if possible.

[Erny]

if you want to change ratio, just select different front and/or rear sprockets.
You can use sprocket calculator here to compare options : https://sprocketcalculator.com/
also more detailed info incli. centers distance is here : https://www.blocklayer.com/chain-sprocket.aspx

[Pielz]

if you want to change ratio, just select different front and/or rear sprockets.
You can use sprocket calculator here to compare options : https://sprocketcalculator.com/
also more detailed info incli. centers distance is here : https://www.blocklayer.com/chain-sprocket.aspx

Oh okay I see! And it tells me the estimated number of links. See, ive never done this before so I'm not sure how to know the lengths of chain and all of this. I just really want to make sure I do this right. I'm thinking about doing 16/48. That should give me the ratio that I'm looking for.

[1976cb750f836]

I was hoping to bump my ratio up to 3 from the 2.7 it is for a little boost but I'm not sure what all is available.

Be sure u go the right way? Going from 3 to 2.7 will increase mph, lower rpm at speed. If u want quicker take off u go the other way. Once u get the conversion on, u can change only the front sprocket for mph, or take off. I have 2 front sprockets, a 17 for take off, and a 18 for long trips.

[Pielz]

I was hoping to bump my ratio UP TO 3 from the 2.7 that IT IS. lol I think you misread what I said

[Pielz]

Thread has been sitting for a bit but I'm thinking of going with the 16T JTF338 front sprocket and the 48T JTR284 rear. Folks that know, will that work? I'm just trying to make sure before I order so I don't get it and realize I have to return it lol

Also how many links for the chain, think 102 would be good?

[Rosinante]

Resurrecting an old (8 months old) thread.  My K7 1978 CB750K needs chain and sprockets.  I would prefer to switch to the 530 chain/sprocket setup, and I just need to know how to ensure they will fit and function properly.  Since the 530 chain/sprocket is not stock, I cannot just order the "stock" setup.  How do I ensure there will be no problems with fitment and function - offsets - mounting holes, etc.?

Anecdotally, I was imagining my current sprockets are non-stock hotrod units with higher RPMs and more impressive torque.  I do not think that now.  I just looked at some specs showing about 4000 rpm at 55-ish mph.  This is how my bike performs now.  I am a little surprised the factory did not set these up for closer to 3500 or even 3000 RPM cruising at 60 mph.  That would be WAY higher gearing, it seems.  In related news:  I also notice these things will do a 14-second quarter mile.  Pretty impressive for forty year-old technology.

[Bankerdanny]

Resurrecting an old (8 months old) thread.  My K7 1978 CB750K needs chain and sprockets.  I would prefer to switch to the 530 chain/sprocket setup, and I just need to know how to ensure they will fit and function properly.  Since the 530 chain/sprocket is not stock, I cannot just order the "stock" setup.  How do I ensure there will be no problems with fitment and function - offsets - mounting holes, etc.?

Anecdotally, I was imagining my current sprockets are non-stock hotrod units with higher RPMs and more impressive torque.  I do not think that now.  I just looked at some specs showing about 4000 rpm at 55-ish mph.  This is how my bike performs now.  I am a little surprised the factory did not set these up for closer to 3500 or even 3000 RPM cruising at 60 mph.  That would be WAY higher gearing, it seems.  In related news:  I also notice these things will do a 14-second quarter mile.  Pretty impressive for forty year-old technology.

Other will chime in on this, but I know that Cognito Moto sells sprockets with the correct offset to run a 50 chain on a K7/K8

[Rosinante]

Thank you!  I am not finding this on their website but I have send them a question.

Please tell me this, if you know:  Would a chain and sprocket set from an earlier CB750 work?  I think the chain might need to be a little longer (later CB750s have longer swing arms, I think), but would the fitment of the sprockets be correct if I used sprockets from, say, a 1976?

[seanbarney41]

You want a cb650 front sprocket...generally 17 or 18 tooth with a 48 tooth rear for any year cb750...you like to accelerate and understand that these engines are perfectly happy at 7000 rpm all day on the freeway run 17.  You are old and boring and think you need lower revs at 55mph get an 18.  ha ha just kidding guys.  102 link 530 chain is long enough, might be able to get away with 100 link...I always buy long so it can be trimmed to correct length, but I have a cut off wheel on a die grinder and good chain tools...even so, I always buy a clip type master link.  The only hassle then, is you will have to buy it separate.

[seanbarney41]

the other alternative is getting any year cb750 front sprocket and mill the shoulder off one side...most front sprockets are case hardened though so warn your machinist that he is in for a challenge or a trip to the grinder

[Pielz]

I think I ended up with 16 in the front and 48 in the back. So one down in the front from I think what stock conversion would be if you're conserving the final drive ratio. I just wanted peppier lower end cause I hate highway riding and love zipping around the city. 102 link chain I believe as well. Bought a 104 and trimmed 2 links off. Worked really well and hasn't stretched more than a tiny tiny bit I'm the initial few miles. I've put 400 miles on this parts unlimited X-ring chain and I've had no issues at all.

Also 75 on the highway I'm sitting at 7000 rpm or so. So I don't have a ton of overhead but that's not speed I use anyway. I like to cruise the back roads

The sprocket numbers from JT sprockets were 16T JTF338 for the front sprocket and 48T JTR284 for the rear. Had the correct offset and bolt pattern I didn't have to mess with it at all. Although I did smooth the sharp edges of the sprocket teeth with a bench grinder wire wheel at the recommendation of hondaman. He said it helps with break-in wear if they're a cast type steel gear which my front sprocket is

[grcamna2]

Brent,Your 750 has a torque-curve which works best with a certain final ratio;with a lighter 530 chain and sprockets it may run well with a larger countershaft sprocket than what you think.The 750 has a long stroke and is well able to be short-shifted through the gears,plenty of mid-range on those engines.

[Pielz]

Brent,Your 750 has a torque-curve which works best with a certain final ratio;with a lighter 530 chain and sprockets it may run well with a larger countershaft sprocket than what you think.The 750 has a long stroke and is well able to be short-shifted through the gears,plenty of mid-range on those engines.

I was honestly thinking of trying out a 17 tooth front sprocket but wasn't exceptionally excited to buy another chain. Wonder if I could make my current chain work? Wonder if there's any risk in doing that? Cause I don't really want to spend another 100 bucks almost on a chain

[grcamna2]

Depends how close your rear wheel is to the front of the adjustment,a 17 is a very small amount and should be easily 'do-able'.