Loose rear sprocket?

[Martay]

Hi,
Adjusting the chain on my 125, i noticed the rear sprocket feels loose. The 4 nuts that are holding it on ARE tight, but the studs are moving within the wheel. There is no rotational movement. I tried to video it on my phone if it helps
https://www.youtube.com/watch?v=BAdCJQI4-kE
Is this to reduce shock through transmission, or is something wrong?
Many thanks
____________________
Eat well, poo hard
Drives: Cavalier 2.0 16v
Rides: Slightly ratted Honda City Express

[mr rip]

you'll probably find that your sprocket is bolted to a backing plate that just slots into a set of rubber blocks in your rear wheel

nothing to worry about, they're there to soften things up a bit when you pull away & slow down

can't say it makes a lot of diference really but it cant hurt eh?

from looking at the vid it sounds a bit clunky it wouldn't hurt to get in there & have a look as the rubbers might be a bit worn out
____________________
never criticise a man until you've walked a mile in his shoes, then when the muck hits the fan you'll be a mile away & you'll have his shoes

[stinkwheel]

That's the cush drive.

The rear sprocket is bolted to the outside of a circular metal casting with a series of segments cast onto the inside face of it (called, imaginatively enough, the sprocket carrier). This slots into gaps in the hub of the rear wheel which are packed with rubber blocks.

As you correctly surmised, this is to give a smoother transfer of power from the engine to the rear wheel.

Worth remembering that the sprocket carrier has a bearing in it in addition to the two rear wheel bearings.

If the play in the cush drive becomes excessive, you either need to replace the rubbers or spaxce them out with slices of inner tube.

Here is a picture of a rear wheel with the sprocket carrier removed.
https://www.wenga.net/ellingly/posties/thumbs/cush_drive_rubbers_mounted.jpg

I do think there is a bit much sideways play in yours though. I wonder if the bearing is ok or if there is a spacer missing between the hub and cush drive or if the wheel nut is a bit loose.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[lukamon]

its called a "cush drive" different types exist but most common is the one where the holes the sproket bolts go through are rubber blocks, when you open the throttle the slack in the chain is taken up with a jerk, the rubber softens the shock
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killa wrote: Im an ass man myself

[Martay]

Awesome, thanks for the info
Il pop the wheel out and have a peek tommorow.
Thanks again
____________________
Eat well, poo hard
Drives: Cavalier 2.0 16v
Rides: Slightly ratted Honda City Express

[veze]

and as stink wheel says, there is a sprocket carrier bearing in there. it is and idea to check it for sideways play to make sure the bearing is good. i check mine everytime i oil my chain for piece of mind.
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tlm50,mt5,sr50. rs125 extrema, cbr 400rr nc29 suzuki gs500e.Honda cbx250 rs . FJ1200 .fz6,fjr1300

[sickpup]

Just need to check something here.

Is there a big circlip holding that rear sprocket on?

[bandit]

Hi

looking at vid It seems to be a circlip thats holding the sprocket on...

There is no sprocket bearing in the type of set up......

You will find there are 4 round cush drive rubbers about size of 20p that have fell to bits... you'll have buy some new ones and i would replace the 4 sprocket retainig studs as well...
Could you post pic when apart

would not ride in this condition in case you do more damage to bike or youself...

Best of luck
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b12 cg125 gt250 kh125 ss50 cg150 CG250cc

[Martay]

Hi,
Yes there is a large circlip holding the sprocket on.
The bike is 'supposed' to be under warrenty still so il get the bike shop to replace them.
Many thanks for the advice
____________________
Eat well, poo hard
Drives: Cavalier 2.0 16v
Rides: Slightly ratted Honda City Express

[sickpup]

So everyone one except Bandit is wrong in what they say.

The sprocket studs go into metalastic bushes that are pressed in to the wheel. These bushes are worn and need replacing. If you don't replace them the sprocket can twist putting force against the circlip which will potentially crack the hub meaning you need a nw rear wheel.

[binge]

I'm with sickpup. If it was a regular cush drive, you wouldn't get play like that in the sprocket, no matter how much the rubbers were worn. You'd get rotational movement though.




Ben