Topic: Checking and Advice on Rear Wheel Assemb.

[Kouros]

This is going to be a milestone for me as I have not made progress on the bike in a long time and am excited to get this done right. My challenge is I did not take this CB750 K4 apart myself and besides the pictures, clymer and microfisch, I have nothing to go by and I've never worked on motorcycles.

I need you to take a look at the wheel setup in the pictures and tell me if I have them set in correct sequence. Then I need instructions how to put the wheel, chain adjuster and brake adjuster all at once so they work together. I'm missing a the chain and I am not even sure if it can be installed later. Please don't assume anything and help me in detail. Thanks in advance.

[Kouros]

Just noticed from the "for sale pics" I saved when I bought it that the shocks were mounted differently that the bottom bolt hole I was going for. The bottom of the shock sits 2.5" or more farther back. I don't see others using it. What is this?

[tmnt328]

Looks like a "lowering block, used to lower the bike or compensate f for a longer shock. Either way its not stock.

[Brown Bomber]

Just noticed from the "for sale pics" I saved when I bought it that the shocks were mounted differently that the bottom bolt hole I was going for. The bottom of the shock sits 2.5" or more farther back. I don't see others using it. What is this?

Those are lowering blocks, (aftermarket) they will make for a harsh ride, and unless you're vertically challenged you don't need them. Mount the bottom end of the shocks right to the eye on the swing arm.

[Brown Bomber]

In the first picture, the sprocket plate looks small compared to the sprocket. Got a side view of that?

[MCRider]

In the first picture, the sprocket plate looks small compared to the sprocket. Got a side view of that?

Early CB750 had a small sprocket plate. Later, from K1 on I'm guessing, had a plate that was nearer to the full size of the sprocket. Don't know when the change was made, guessing no later than K1.  During the time when they were lunching chains.

If the OP is a K4, the sprocket plate/guard was changed at some point for an early one.

This is the size on my K2:

[Kouros]

Thank you. The original sprocket plate for this motorcycle was is larger by 1/2" in dia. than the one in the pictures, but that sprocket may be done. Also found some answeres by Hondaman:

That plate is a part Honda called a "splash guard". It was supposed to help reduce the oil slinging from the chain at the rear and help keep the bike cleaner. This was due to the early 750 having a high oiling rate from the countershaft's oiler, due to lower gearing and larger oil settings than the later bikes.

If you have a genuine Honda rear sprocket, that sprocket has a recessed face that is the same depth as the thickness of the stamped steel used for this splash guard, so the overall sprocket thickness with the plate installed is the same as the width of the sprocket teeth. Aftermarket sprockets, including the current crop of JT/EMGO units, do not have a correct recess: it is too small in OD (or nonexistant) and the guard ends up too wide from being stacked on top of the sprocket, often scraping the inside of the chain gaurd. Many have thus been removed.  

I got this 48 tooth one from Dennis Kirk by mentioning the correct year and model. Should I not be using it if I don't have chain guard?

Also, can anyone walk me through installing the rear wheel in steps please?

Thanks.
-K

[MCRider]

Thank you. The original sprocket plate for this motorcycle was is larger by 1/2" in dia. than the one in the pictures, but that sprocket may be done. Also found some answeres by Hondaman:

That plate is a part Honda called a "splash guard". It was supposed to help reduce the oil slinging from the chain at the rear and help keep the bike cleaner. This was due to the early 750 having a high oiling rate from the countershaft's oiler, due to lower gearing and larger oil settings than the later bikes.

If you have a genuine Honda rear sprocket, that sprocket has a recessed face that is the same depth as the thickness of the stamped steel used for this splash guard, so the overall sprocket thickness with the plate installed is the same as the width of the sprocket teeth. Aftermarket sprockets, including the current crop of JT/EMGO units, do not have a correct recess: it is too small in OD (or nonexistant) and the guard ends up too wide from being stacked on top of the sprocket, often scraping the inside of the chain gaurd. Many have thus been removed.  

I got this 48 tooth one from Dennis Kirk by mentioning the correct year and model. Should I not be using it if I don't have chain guard?

Also, can anyone walk me through installing the rear wheel in steps please?

Thanks.
-K

If the sprocket has a recess on either side, the recess goes facing outwards. Otherwise, if the sprocket is designated for a CB750 then I wouldn't hesitate to use it. As HM mentions, later, aftermarket sprockets often do away with the recess to keep costs down.

The guards/plates are completely superfluous and are often discarded without harm.

As to install, 2 methods. The swingarm end pieces in place or not in place. Also, do you have an endless chain, or a chain with a masterlink? I prefer to have the end pieces out and use a chain with a master link. This is the method for a stock 4-4 exhaust system, but I'd still use it for any exhaust. Assemble the wheel completely, with axle and chain adjusters in place, with axle nut lose. Offer the assembly to the swingarm, slide it into place. Put the end pieces on and secure them with the 8mm bolts, loosely, leave those bolts loose till the end.

Hook up the chain masterlink, the brake plate stay bar, then the brake actuating rod, with the spring, barrel and adjuster nut.

Finally adjust the chain. Once its adjusted you'll have pressure on the end pieces from the adjusters, time to snug down the bolts fixing the end pieces in place.

Now during this time the axle nut has been no more than finger tight. Actuate the brake. This will center the brake plate in the drum. While holding the brake, tighten the axle nut firmly. release the brake and tighten the axle nut fully to 70ft lbs or so.

I've missed some finer details I'm sure.

[Kouros]

You rock. Nice step by step. Thank you very much!

[MCRider]

You rock. Nice step by step. Thank you very much!

You're welcome.

Missing steps. After torquing axle nut, sit on the bike and try the brake. Be sure it is adjusted properly, about an inch or so of travel. I skipped this step ,,, once... and never again. You'll pull out for a test ride and have no rear brake.

Adjust the brake light switch to turn the light on properly.

[Kong]

MCRider,

Not to dispute your method; pick the wheel up and put it on, and I too prefer to have a master-linked chain, but the thing I wanted to mention was your rear axle torque recommendation.  I don't have the manual for my 550 but the rear axle torque for my Harley, which has a 19mm axle, is 50 foot pounds, and so I thought your recommendation for 70, or so, sounded a bit high.  With the Harley's the reason the torque is seemingly light is because - although neither the factory nor most Harley Owners would ever admit it - is that the factory is sloppy in cutting their center bearing spacers and if yours is short and you over-torque that nut you can just about bet on a rear wheel bearing failure within 5,000 miles or less.  

[MCRider]

MCRider,

Not to dispute your method; pick the wheel up and put it on, and I too prefer to have a master-linked chain, but the thing I wanted to mention was your rear axle torque recommendation.  I don't have the manual for my 550 but the rear axle torque for my Harley, which has a 19mm axle, is 50 foot pounds, and so I thought your recommendation for 70, or so, sounded a bit high.  With the Harley's the reason the torque is seemingly light is because - although neither the factory nor most Harley Owners would ever admit it - is that the factory is sloppy in cutting their center bearing spacers and if yours is short and you over-torque that nut you can just about bet on a rear wheel bearing failure within 5,000 miles or less.  

No problem. Here's my source:
http://www.salocal.com/sohc/tech/torquetable.htm

70 is at the high end of the 58 to 72 range. (the "tear (sic) wheel axle nut") As to the bearing/spacer stack, the way it is on the CB750, I can't conceive of any way you could drive a bearing to failure from overtightening the nut. The entire load is carried thru the center race of the bearings which contact the spacers. With no loads on both races, no failure.

Truth be told, I doubt I ever tightened it to 70, probably more like 50 to 60. But I'm trying to be a better boy and follow the instructions.   

[Kouros]

There is a recess on the sprocket and the plate is on the opposite side.

So if the is facing out like mentioned above, the plate will be facing towards inside.
But if the plate is facing outside, the recess is is facing inside.

Do I definitely not want the sprocket

-Kplate inside regardless of the recessed side of the sprocket?

[MCRider]

There is a recess on the sprocket and the plate is on the opposite side.

So if the is facing out like mentioned above, the plate will be facing towards inside.
But if the plate is facing outside, the recess is is facing inside.

Do I definitely not want the sprocket

-Kplate inside regardless of the recessed side of the sprocket?

I'm not following you exactly, 

So, the sprocket drops on the studs with the recessing facing out, away from the hub. The plate fits in the recess. Period.

Questions? Do we need pictures?

Why do you not want the sprocket. Just swap it around so its right.

FYI: If the recess is facing in or towards the hub, the sprocket will be slightly out of line with the front sprocket. We're talking small bits here, but that's the deal.

[Kouros]

My Old sprocket/plate seems to like in the image you posted above. The new one I got has the recess and the riveted plate on opposite sides. But like you say, if its small bits, then I'll just move on. Thanks again.

[MCRider]

Now I see! That riveted on plate never occurred in Hondaland. They were always independent pieces that could be installed or left off, like your old one. I've never seen one like that.

And I see the recess is opposite the plate, and you CAN'T just swap them as the plate is riveted. So, my apologies.
That old sprocket looks in good shape, did it need replacing?

If so, I'd use the new one. Sight down the sprocket edge with a straightedge and see if it lines up with the front sprocket. If not, I wouldn't be shy to space it out with some washers, or maybe drill out the rivets and bolt it back on the other side.

If the old sprocket didn't need replacing, I'd flip a coin.  Curious, who sold you the new one?

[Kouros]

Dennis Kirk and I called with year/make/model!

The Old sprocket looked to be in good shape and its been powder coated recently.
At some point I forgot I had it and ordered a new one among other things. I'll use the old one.
Cheers

[MCRider]

I see. Carry on!   

[Brown Bomber]

You could use the new sprocket with the small plate on the inside, and the old plate on the outside where it is recessed. That would help keep the hub clean, plus it would be something different and make for some interesting conversation.....just a thought.

[steam-powered man]

-- did you install sprocket nuts with removable/blue loctite?  torqued?  with keeper plates?  (yes, i use all 3)
-- when the wheel is mounted, axle nut snug and brakes not dragging, the wheel should spin freely.  if not, bearings may not be installed correctly.
-- don't forget checking the spoke tension

[ZoomyZen]

You rock. Nice step by step. Thank you very much!

Indeed.  This is shaping up to be a great forum for me as well!

[Kouros]

Wheels were laced, balance and tuned by Buchanan. So no worries there.

I'm just mocking up and have not torqued anything yet. I do have the keeper plates and will install.
The bearings are new and installed correctly.