[Turbo DV8]

OK, I've 28 years riding experience, but all on shaft drive bikes, so I'm a chain drive virgin. I was playing around with the rear sprocket while cleaning the chain. While fiddling with it, I rocked the sprocket back and forth by hand and noticed it seems to have a bit of free-wheel in it. That is, it appears as if the sprocket rotates separate from the rest of the hub, as the hub did not turn when I rocked the sprocket back and forth. What is the reason for this?

 

[Aargee]

it appears as if the sprocket rotates separate from the rest of the hub, as the hub did not turn when I rocked the sprocket back and forth

This cannot happen; if it does, something seriously wrong. Fix it before things turn ugly.

 

[Aufitt]

I have not had the wheel out yet, or seen an exploded parts diagram, but guessing just the cush drive rubbers doing its thing. All roadbikes have this.

 

[Michael]

I have just been looking around for an exploded diagram, but have not found one. However a little play is normal for a chain driven motorcycle. Here is a wiki article about the cush drive:

Cush drive - Wikipedia, the free encyclopedia

 

[arn]

The cush rubers are a SNUG fit, meant to reduce sudden jerks on the chain.

If you can provoke noticeable play with your hands, they may need changing. Normally, though, they'd require that only after significant distance.

 

[hondafan]

If you want to get rid of the play, remove the hub and put thin plastic shims in the cush rubbers. I doubt if it will make much difference unless they are really loose.

 

[jsonder]

" it appears as if the sprocket rotates separate from the rest of the hub"

Not normal. The drive sprocket usually has a little slack on the shaft that turns it; however, the rear sprocket should be bolted to the rear wheel and should not have any slack between the sprocket and the rest of the wheel/hub.

Are you sure that you are not talking about the chain fit on the rear sprocket?

 

[Aufitt]

AGAIN!

It is not a dirtbike, the sprocket does not bolt directly to the wheel, it mounts to the sprocket hub which drives on cush rubbers, it absorbs vibrations and smooths the drive.

Now everyone - go grab your rear sprocket and see you will have approx 5mm play back and forth (at the hub).. this is normal.

 

[Turbo DV8]

Yeah, that's about it... 5mm or a little less. I know my CX500 shafty has it's cush drive (ramped spring) inside the engine between the output shaft and drive shaft. I was leaning toward cush here, too, but wanted to check, being unfamiliar with chain drive.