Topic: rattly, gritty sound from rear of bike, rear brake affected

[blUtt]

hope i'm in the right place here. bike is new to me, and i'm starting from scratch. someone just chewed me out for posting this in a DOHC forum (i didn't know what DOHC was til i came to this site, and it defined SOHC)! anyway...
bike: 1974 cb750
yesterday my chain was suddenly very loose, so i moved the rear wheel to increase tension. no problem. but when i rode it this morning, suddenly there's a strange sound from the rear wheel area. the only way i can describe it is that it's as if there's a bunch of sand inside the rim, spinning around as i roll (yes, i know that's not what it is). also, when i apply my rear brake, it even feels gritty, not the smooth application i'm used to. the adjustments i made to each side are even. all i did was move the wheel a fraction of an inch! i'm guessing that may be the sound of my chain, but there was no such sound before, and there certainly was no brake issue. i'm not even sure i should be riding it while this persists. any advice on how to proceed/where to focus would be great. someone in the other forum mentioned "chain binding", but i wouldn't know exactly what that meant or how to remedy it. thanks in advance to anyone who can help me out!

[jsaab2748]

Remove the chain and spin the wheel with the bike on it's centerstand. if you still feel/hear the noise, suspect rear wheel bearings/brake problems. If noise is gone, suspect chain, or other driveline problems. There are 3 bearings in the rear wheel of an early 750, one for the hub, and two for the wheel itself. To get at the bearings properly, it's esier to let a shop remove the retainers with the proper tools. Just speaking from experience, hope this helps.

[Sam Green Racing]

Blutt,

Welcme to the forum.

See how easy that was.

When you have sorted it or just found what it was come back and tell us.

We do have fun on this forum, its not oily hands all the time.

Enjoy. Sam.

[Dennis]

See, NO ONE chewed you out!
And you're in the correct place anyway. And you DO have an SOHC4!!
So RELAX!! And Welcome once again!

Anyway, the sudden looseness in tha chain and accompanying sound are certainly curious. I would tend to go along with jsaab's suggestion to isolate the wheel from the chain and locate it in that manner.
Is the sound steady or cyclical and increasing with road speed?
A word of warning however, broken chains on these engines almost always cause severe damage to the engine cases, not to mention being a safety issue for the rider.
Do you really want or need to ride this bike until you find the cause of the noise? How lucky do you feel?

[TwoTired]

blUtt,
The symptoms you describe are very much like what I had on my 78 CB550.  However, the rear wheel bearing that went out was on the chain side.  The bike got pretty weird, like it was on marbles when power was used.  What fooled me for a while was, while on the center stand the rear wheel turned just fine.  About half the rollers in the bearing on the chain side were gone.  Under power they would all squirt to one side of the bearing and the wheel would shift on the axle.  Off power and they would walk back around the axle and center the wheel again.  Anyway, I paid the $20 asked by the Honda dealer to replace the bearing.  Watching him wrestle and grunt while using the special tool on that retainer was more than worth it in entertainment value alone.
Cheers,

[blUtt]

thanks to everyone for their input and suggestions! it's great to be able to get straight-talk from people. i know no one personally who can help me with this bike, and i'm winging it on my own. i'll look into the couple of things mentioned and report back. -b.

[Buffo]

  2tired, that is indeed worth every penny of $20.00

I do hope you were sipping a cool drink (with sipping noises) while the Honda guy "wrestled and grunted with his special tool"

HA HA fu(king Ha Ha

Buffo the Egotistical and Stupid ---and now the Easily Entertained