Topic: 78 750f 530 chain links?

[bender01]

Ive decided on converting to 18/48 sprockets on my 78 750f. Ive found lots of info but nothing on how many links for the chain! I just want to put on standard roller chain. Any body remember? Thanks.

[nobody]

I had a little chat with Hondaman last night and was told that there's a bit of an odd phenomena with cb750 front sprockets. He said that not only does a 17t sprocket transfer more power it actually raises your top speed by ten miles an hour or so.

[bender01]

Well if I went with a 17/48 combo How many links in the chain will I need?
I think I might get more life from the 18/48 according to my searching here. Its been done alot but No one posts how many links for the 530 chain on a 78750f. I really dont care which I go with I just want a "This worked on my 78750f" from someone. Thanks.

[nobody]

The 18t front will put less stress on the chain but according to Hondaman, modern chains will handle the stress much better today than they did thirty years ago.

I can't tell you how many links as I have yet to even start working on my 78f. Do you have your old chain? If you do you should be able to string that up as close as you can and guesstimate how many more or less links you need to complete the chain. That's what I would do. Sorry if I'm not of much help, just passing on a tip.

[XN]

I used 104 links on my conversion. But I have a K8

[bender01]

Thanks! XN. Thats the answer im looking for. Although its a K. So
17/48 530  =?
18/48 530  =?
 1978 cb750f 530 chain sprocket conversion.

[754]

Its over 100, just buy a 110 link, fit and trim..

 be good for many  different sprocket combos...

 like my favorite.. 17/54..

[Cqyqte]

An 18/48 combination will take a 104 link chain according to JT Sprockets

[XN]

Thanks! XN. Thats the answer im looking for. Although its a K. So
17/48 530  =?
18/48 530  =?
 1978 cb750f 530 chain sprocket conversion.

I've slept since then, but i think it was the 17/48

I just got a 110 link rk x ring from z1 enterprises 

[Terry in Australia]

A 104 link chain is fine for a 69-76 K series CB750, but no-one here has mentioned yet that the swingarm on a 77/78 F is an inch longer, (part of the reason why the 77/78F was the best handler of the lot) so you'll want a minimum of an extra 4 links, so just to be safe, buy a 110 link chain and adjust as necessary.

Also, with respect to Hondaman, he probably wasn't talking about the 77/78 F's when he suggested dropping the front sprocket to a 17 toother, you see, the 77/78 F's were geared differently, and had a lower 5th gear ratio than the 69-76 K's to make use of the more powerful 77/78 F engine. I think 18/48 will be a good choice for all round performance. Cheers, Terry.

[MFHP]

fifth gear different in the F2? Sorry, but that's IMHO impossible. The fifth gear's part number for the F2 is 23481300020 which makes it a carry over part from the early K's.
Only Final drive with a ratio of 3.071:1 (14/43 sprockets) on the F2 was shorter than the early ones. That was to make up for some loss of low end power and with respect to the higher revving the changed valve drive allowed. The rest is despite of some changes in part numbers for some of the gears (its a mixture of early K's, 76F , K77, F77 and even Goldwing numbers) interchangeable to at least K77.


Mike

-----------------
K77, CB500K1

[Yoshi823]

According to the Haynes manual (#131) the ratios for the 750F2/K7 are as followed:-

1st.....2.500:1
2nd.....1.708:1
3rd......1.333:1
4th......1.133:1
5th......0.969:1
Primary drive ratio  1.708:1

[Terry in Australia]

fifth gear different in the F2? Sorry, but that's IMHO impossible. The fifth gear's part number for the F2 is 23481300020 which makes it a carry over part from the early K's.
Only Final drive with a ratio of 3.071:1 (14/43 sprockets) on the F2 was shorter than the early ones. That was to make up for some loss of low end power and with respect to the higher revving the changed valve drive allowed. The rest is despite of some changes in part numbers for some of the gears (its a mixture of early K's, 76F , K77, F77 and even Goldwing numbers) interchangeable to at least K77.


Mike

-----------------
K77, CB500K1

That's interesting mate, Yoshi823 has posted the ratio's for a 77/78F, here are the ratio's listed for the 69-76 K and F models. (From my Cycleserv manual)

2.500
1.708
1.333
1.097
0.939

Cheers,

Terry.

[bender01]

Im almost ready to buy them from z-1
JTF 288 18T
JTR 284 48T
  Theyre for 75-76 Supersports. If you look for 78 sprockets its 630 only listed. Will the earlier sprockets fit comstars? I imagine the front will but Im worried about the rear?

[Yoshi823]

Well 18-48 would give a ratio of 2.666 as against 2.87 as standard (15/43).

17/48 would give you 2.82, so at least you would have a cheap alternative to change to if you found 18/48 too much.

[MFHP]

fifth gear different in the F2? Sorry, but that's IMHO impossible. The fifth gear's part number for the F2 is 23481300020 which makes it a carry over part from the early K's.
Only Final drive with a ratio of 3.071:1 (14/43 sprockets) on the F2 was shorter than the early ones. That was to make up for some loss of low end power and with respect to the higher revving the changed valve drive allowed. The rest is despite of some changes in part numbers for some of the gears (its a mixture of early K's, 76F , K77, F77 and even Goldwing numbers) interchangeable to at least K77.


Mike

-----------------
K77, CB500K1

That's interesting mate, Yoshi823 has posted the ratio's for a 77/78F, here are the ratio's listed for the 69-76 K and F models. (From my Cycleserv manual)

2.500
1.708
1.333
1.097
0.939

Cheers,

Terry.

yep,
knew about those differing numbers , but definitely tend more to trust the OEM's part list which tells me that the ratio isn't  changed. By the way: the counter shafts fifth gear for F77/K77 is a 392 (= F1) parts number and the F1 has the same 5th ratio judging from your lists as the early K.

But back to the original thread:
I would recommend getting as close to the F2 final ratio as possible.
Rear sprocket hole pattern is same for all models. Front sprocket fastening pattern is different between early K/F1 and the K77/F77.

Mike

[bender01]

http://www.z1enterprises.com/catalog.aspx?pid=HPMP2
 If this link comes up. Which 18/48 530 sprockets are known to fit 1978 750 F3?





 Oh now I see. Go count the splines on mine! Sorry.

[754]

The final drive gear is diff on 77/78..F & K, that is the gear on the sprocket shaft & its mate.

 Front sprockets in 530 fit from 69 -78 just the mounting setup is a washer and bolt the last 2 years.

 Also on 77/78 check for wear on the countershaft splines, I have seen a soft one that wore prematurely.. only went 30 years.. not like the older ones..

[Terry in Australia]

yep,
knew about those differing numbers , but definitely tend more to trust the OEM's part list which tells me that the ratio isn't  changed. By the way: the counter shafts fifth gear for F77/K77 is a 392 (= F1) parts number and the F1 has the same 5th ratio judging from your lists as the early K.

But back to the original thread:
I would recommend getting as close to the F2 final ratio as possible.
Rear sprocket hole pattern is same for all models. Front sprocket fastening pattern is different between early K/F1 and the K77/F77.

Mike

Well that's interesting too Mike, but I just checked the Factory manual in the FAQ's here for the 1969-75 ratio's, and guess what mate? They're the same that I quoted from the Cycleserv manual? As follows:

2.500
1.708
1.333
1.097
0.939

So what do I believe, the factory workshop manual, or, according to your posts, the factory parts manual? I'm guessing that like Frank suggests, the gear on the 77/78 F and K countershaft (and it's mate) are different from the earlier bikes, and that's what gives it a slightly lower final drive ratio. Cheers, Terry.

[MFHP]

sure, believe all these figures. But did you ever consider that all these lists might just rely on the same base data release from Honda way in the past more than 30 years ago. And I'm still convinced that someone in that past did make a mistake which was copied afterwards. And just because several sources tell the same, it still might be wrong because their all just copies from original Honda data. And it would not be the first time Honda posted something wrong.
I would really be interested in figuring out which off the sources is the right one.
Does anybody out there currently have a transmission on the bench and just be so kind and count the 5th gear teathes and post it together with the model it is from? Maybe we could get a good comparison of all the mayor modells together.

Mike

[voxonda]

Mine is on the bench, will count tonight. Just before counting sheeps Ï quess

It is a '76 F1 transmission for sure.

Rob

[MFHP]

almost forgot, that my spare K77 Engine has its transmission pulled. Just came back from the basement after counting:
5th gear Main: 33
5th gear counter: 32  (the K77 Haynes says 31)

Final gear on countershaft 43 teeth; my Haynes manual and the OEM's part list says 48;
Its mate on the finalshafts counts 50; Haynes and part list say 56.

Seems to me that Honda made a mistake when counting  

Mike

[Don R]

I have a 77K out in the shop with the cases split, I'm not sure which gears to count though.

[MFHP]

I have a 77K out in the shop with the cases split, I'm not sure which gears to count though.

5th gears are the ones on the left end of the main and counter shafts.
Final drive gear is the biggest one on the countershaft. And there is only one on the final shaft

Hopefully you come up with the same numbers as I did   

Mike

[voxonda]

Counted my numbers, and it is a '76 F1 engine: 33 to 32 = 0.969

Rob