Topic: How do I align the front sprocket to the rear?

[Mista750]

I bought a 76 CB750F and the PO swapped out the motor from a 78 K. I finally got the bike running and noticed that no matter how I much I tried to align the rear wheel, I couldn't get my chain to quiet down. So removed the chain to check for alignment and found that the front sprocket is about a sprocket width off to the left. Any advise on how to fix this?

[bert96]

Maybe an off set sprocket from Cyclex.

http://www.cyclexchange.net/Chain%20Sprocket%20Page.htm



Bert

[martin99]

I have a '77F, not a K.

Your pic shows what looks to be a nut between the sprocket and seal. According to my parts list it shouldn't be there on an F. Might be the problem with yours?

[750K]

Easiest way around it is the 10mm offset rear sprocket, 77-78k's have the front counter shaft and rear sprocket carrier 10mm further outboard as well as a wider swing arm and left rear shock mount on the frame. So getting an offset sprocket is most likely easier unless you have a complete 77-78 rear end setup to scavenge parts off of.

[Mista750]

Awesome! That will work! Thanks Bert!

Maybe an off set sprocket from Cyclex.

http://www.cyclexchange.net/Chain%20Sprocket%20Page.htm



Bert

[Bailgang]

Easiest way around it is the 10mm offset rear sprocket, 77-78k's have the front counter shaft and rear sprocket carrier 10mm further outboard as well as a wider swing arm and left rear shock mount on the frame. So getting an offset sprocket is most likely easier unless you have a complete 77-78 rear end setup to scavenge parts off of.

It takes just a bit more than a complete rear end set up from a 77/78 because the top left side shock mount on a 77/78 frame sticks out 10mm farther out as well. I put a 77k engine in my kid's 73k frame and I had all the 77/78 suspension hardware, sprocket hub and spacers to do it but that left shock mount stalled us. Not a big deal to fix except the frame was 2 1/2 hours away from here where my welder is. The bike needed new sprockets anyhow so my kid left the 73 rear end setup intact, got the rear offset sprocket from cycleX and all is well.

[754]

It takes less than that , 4 machined spacers or. 1 big one for the rear sprocket..may need longer studs..
Or use the 77/78. Rear carrier. ( and inner spacer). That will solve sprocket problem.
Now you may have to fiddle with axle spacers and shock clearance.

A 77/78 swingarm and axle off correct model. Will help too but is an inch or a bit more longer..needs longer chain

[Bailgang]

Now you may have to fiddle with axle spacers and shock clearance.

And that was what the issue was with ours. We would've either had to mess with spacers if using the 77 carrier in the 73 swingarm or mess with the top left shock mount when using the 77/78 swingarm and carrier. Not a big deal actually except frame was there and equipment to do it was here. With the cycleX offset rear sprocket mounted on the 73 carrier we weren't able to use the chain guard and the chain does clear the shock ..... but not by much.

[lucky]

The PO screwed you. Sloppy and dangerous workmanship.
IF it has that old #630 chain I would get rid of that and use #530 sprockets and chain.

You will still need that special sprocket from cycle -X for the front countershaft.

[Bailgang]

IF it has that old #630 chain I would get rid of that and use #530 sprockets and chain.

That's actually a good point because I think the cycleX offset rear sprocket was only available for a 530 chain.

[Mista750]

When i bought the bike, fortunately the PO included the original 76F motor but don't know the condition. I will be looking into rebuilding it and hopefully using it again. But for now, I'll have to stick with the 78K motor.

The chain currently on the bike is a 630. So I looks like I'll be picking up a 530 chain, front sprocket and 10mm rear offset sprocket.

The PO screwed you. Sloppy and dangerous workmanship.
IF it has that old #630 chain I would get rid of that and use #530 sprockets and chain.

You will still need that special sprocket from cycle -X for the front countershaft.

[754]

Offset front wont helpunless you can run it negative offset.
 Like I said cheapest way is spacers.. If you were here. A lot of days I would bang them off for like 15-25 bux for the four..

 Most guys with a jig saw diegrinder and drill, should be able to carve a one piece one out of 3/8 alloy plate..n an hour or hour and a half..

[Mista750]

Not a front offset but a 10mm rear offset should do it for me. Don't you think? I measured that sprocket plate and it's about 10mm thick.

Offset front wont helpunless you can run it negative offset.
 Like I said cheapest way is spacers.. If you were here. A lot of days I would bang them off for like 15-25 bux for the four..

 Most guys with a jig saw diegrinder and drill, should be able to carve a one piece one out of 3/8 alloy plate..n an hour or hour and a half..

[754]

Yes i know,i dont know why anyone brought up the fronts.

 3/8 = .375    10mm = .394
.   Close enough..

[scottly]

IF it has that old #630 chain I would get rid of that and use #530 sprockets and chain.

You will still need that special sprocket from cycle -X for the front countershaft.

Lucky, how many times do we have to remind you that the 630 chain was introduced in 1977, and the early chain failures resulting in case damage were with 530 chain?

[lucky]

IF it has that old #630 chain I would get rid of that and use #530 sprockets and chain.

You will still need that special sprocket from cycle -X for the front countershaft.

Lucky, how many times do we have to remind you that the 630 chain was introduced in 1977, and the early chain failures resulting in case damage were with 530 chain?

The 1978 engine I got had a hole in the engine case and it had the 630 chain.
And the 1978 models had the thicker engine case in the area around that countershaft sprocket.
BTW I do not like that big fat heavy ugly chain.
IT is the WEIGHT I just do not like. Do I have to keep reminding you all? LOL..lol
Cycle-X uses #520 chain on their powerful road racing motorcycle.