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Chain slack ? please help
https://www.cbr125world.com/forum/viewtopic.php?f=18&t=240		 Page 1 of 1
Author:  cbr125r [ Thu May 05, 2016 8:21 pm ]
Post subject:  Chain slack ? please help
My wife has a 2007 cbr125 with 9000kms on it I also installed the full performance pack on the bike.
I am having issues with chain slack now and not sure why the bike was bought used few months ago 8500km put on by previous 2 owners.
I have cleaned and lubed chain from day one of owning this bike and had slack set around 35mm it had a leaking rear tire took wheel into to get replaced put tire back on lined everything back up set slack to 35mm again.

Checked it the other day cause it seemed to be sagging and now some how was at 45-55MM in slack so I loosened off axle bolts re aligned and adjusted to 35mm torqued axle bolt.
We went for a ride after that for about 30mins came back bike sat overnight checked it today back to 45-55MM driving me crazy any ideas ? the rear sprocket looks fine and the front is the new one from the performance pack.
Any input would be greatly appreciated about this.
Thanks in advance.
Author:  mmiller [ Thu May 05, 2016 8:36 pm ]
Post subject:  Re: Chain slack ? please help
Odd...I was going to say if the axle nut was not tight enough or the adjusters this would cause that but according to your post you torqued it. Normally, when a chain is on the out's it will exhibit behaviour like that (continually stretching) but with only 9K on the clock, and presumably the stock DID O-Ring chain, this is abnormal. My original DID O-Ring chain that comes with the bike from Honda lasted me about 30K - mind you, I looked after it.

About the only thing that comes to mind is that I prefer to set them in the middle of the spec - 30mm. Are you measuring it from the same place each time? I have a specific ruler I use and I slip it behind the swing-arm and the chain in a place where there's a lip. I slide it up against that lip and that's where I measure it. It's roughly half-way and that way I'm using the same location. It's also important to use the center of the chain as the reference point - not the bottom.

Not sure what else to say. Nothing really comes to mind. I've never had an issue with the continual stretch except when the chain was basically finished.
Author:  cbr125r [ Fri May 06, 2016 9:36 am ]
Post subject:  Re: Chain slack ? please help
Hi
Yes I measure mine from the same place with a mm ruler.
I don't think the bike was very well looked after chain and sprockets where disgusting before I cleaned them.
I am just worried about the over all safety as it's my wife riding it not me.
What are the exact torque specs I have found 65lbs.
I will re-adjust one more time to 30MM and see what happens should you do this before or after a ride?
Thank you
Author:  mmiller [ Fri May 06, 2016 9:57 am ]
Post subject:  Re: Chain slack ? please help
It sounds like you're measuring the same way :top:

The exact specs are;

Chain Slack = 25 - 35 mm
Axle Nut Torque = 44 lb-ft

I would suggest, if aiming for perfection, tension the chain after riding (warm) and then always check/adjust when warm. Either that or always do it when cold - consistency would be more important (just like with measuring the slack). In theory, the chain would grow when warm and contract when cold. This is why they recommend lubing the chain when hot. The idea is that as it cools/contracts it will suck in the oil.
Author:  mmiller [ Fri May 06, 2016 10:08 am ]
Post subject:  Re: Chain slack ? please help
If the measured slack continues to grow following those steps, then I would suggest a new chain. To me, it doesn't sound likely at that mileage but if it was never looked after then ?

If you get a new chain you want a DID X-Ring chain or O-Ring chain (in that order). Nothing else will do - trust me.
Author:  DBeck [ Mon May 09, 2016 4:01 am ]
Post subject:  Re: Chain slack ? please help
Hi,
On the topic of chains etc, I was wondering what everyone was using to lube their chains?
Any recommendations of good products, especially one that stick and don't fling all over the wheel?
Thanks
Author:  mmiller [ Mon May 09, 2016 9:29 am ]
Post subject:  Re: Chain slack ? please help
Personally, I use Kerosene to clean it and 80/90 gear oil to lubricate it. Doing that on a fairly regular basis got me 30k out of the original chain and even then, it was a toss-up as to whether to replace it or not.

But, the gear oil does fling.... It's the tried & true method, I just wipe the bike down after a run. There was some DuPont spray that was talked about pretty extensively on the Ducati forums. Apparently it's really good stuff but I think they stopped making it?
Author:  cbr125r [ Mon May 09, 2016 5:40 pm ]
Post subject:  Re: Chain slack ? please help
I have been using motul chain lube seems OK
Author:  cbr125r [ Sat May 28, 2016 7:50 am ]
Post subject:  Re: Chain slack ? please help
Would changing the sprocket in performance pack make any difference in chain slack issues.
Making it seem longer that its almost at the replace marks
Bike has 9k on it could it need a new chain ?
Author:  mmiller [ Sat May 28, 2016 10:25 am ]
Post subject:  Re: Chain slack ? please help
Yes, the stickers on the swing arm that tell you when to replace the chain due to stretch are based on the stock sprockets front and rear so they are no longer valid when you change it. This is true of all bikes so ignore that. If you go up a tooth in the front then the chain will be shorter (and the wheelbase will be shorter) and if you go down a tooth the the chain will be longer and the wheelbase will be longer.

If the chain is shot already (stretched excessively) then changing the sprocket will make it worse as it's longer yet.

If you cannot get/keep the correct tension on the chain then the chain is shot. You can use a standard length replacement chain with the new sprocket - just ignore the label.
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