Chain going loose

[FrogZ]

Lainie has been having a bit of trouble with her chain going loose.
Shes no idiot and neither is Tony so we can rule out all the normal stuff.
SO what are some wierd ones?
I am going to say that it is hitting the frame/swingarm and stretching it.
I am going to guess Lainie has the suspension soft so she can reach the ground and when she hits the big bumps the swingarm is reaching its limit of travel and the frame is either grounding on the swingarm or frame somewhere and stretching the chain (no matter how heavy it is).
Hoiping the nylon block is cut up to shit.
There are screw and lock nut chain adjusters so i dont see how it can be moving them. Ergo it must be stretching the chain to get it loose and I can think of nothing that could do that otehr than described (like a TL1000 apparently).
Anyone ?

[Gosling1]

sounds a bit strange......first guess would be " its old and stuffed " , but this has already been ruled out ....

If it has been bashing the s/arm, then there should be some evidence of this, wether it can be fixed or not is another thing altogether.

Maybe excessive play in the cush-drive in the rear sprocket , and this is causing excessive wear and chain stretch ???? just a thought...

[Barrabob]

How old is the chain??? mine is 40000kms old and needs frequent adjustment atm and although it went well for the first 30000km I asume it is nearly time for a new one.

I use lube and and clean it but I also use the bike daily as a ute and tend to screw the throttle a bit so i supose once the chains buggered its time to replace the whole lot with new stuff.

I think it was a flood i rode around in for a few days that buggered mine it developed a few tight spots during that.

Grabbing it at the back of the rear sprocket and seeing how far you can pull it off the sprocket will tell ya how buggered it is but as you say frog these guys arent mugs.

[FrogZ]

Yeah but Lainie is on a GPX250.
They are like belly buttons and no one reports excessive chain stretch.
The only other thing is she has been unlucky enough to get a bodgey chain. She reckons 100k out before it is loose enough to hear and start messing up the gear changes
Hmmm.. swingarm bushes maybe, wheel bearings ?? But these are all pretty extreme stuff (isnt it?).

[Barrabob]

hmmm someone needs to grab the front of the bike and someone on the back and have a push and pull and see if theres any movement in there.

Either that or all the grease has gone out of the chain.

[Lainie]

Thanks guys The chain and sprockets have done about 1,000km now I did change it a little while ago but really don't ride that much.

[FrogZ]

had a thought in my sleep.
Undo all the rar sprocket bolts (yeah I know they are countersunk)
Spin wheel with them loose, hopefully a "centreing" will occur.
retighten.

An old machinist told me no sprockets were prefectly round (but the talon ones from Titmans come close apparently) and it is that causes tight spots not the chain itself.
I still dont think thats what it is but...

[Jonno]

Quality chain?
Out of round sprokets?
Chain set too tight to start with?
Wirring noises?

prefer a loosish chain than a cracked internal/external gearbox casing

Definatly stretching.

[Lainie]

Quality chain? Was a Heavy Duty Chain
Chain set too tight to start with? Doubt it Tones is VERY Picky
Out of round sprokets?
Wirring noises?


Thinking I am gonna tighten it AGAIN and go for a spin down to RR and ask lots and lots of

Or could be the heavens telling me to upgrade now

[Gosling1]

Thanks guys The chain and sprockets have done about 1,000km now I did change it a little while ago but really don't ride that much.

Laines - if you have only done 1000k on this new chain, its probably still 'bedding in', and is still going through its first 1/2 dozen adjustments, until it settles down.

just a thought

[Lainie]

Well could be Gos and I was thinking the same thing but I really know nothing bout them It's so annoying when riding though and hearing it Oh well just means more time spent with the bike

[Phil]

could it be the rear shock is cactus and the chain is working as the suspension.

this happend to tim on his 750 with that silly shock set up they had........

also its not unheard of for the shock to loose its gas wIth not a lot of use.

HTH

[rotaboy]

im no expert here but would it be worth taking a measurment of the chain over x amount of links then when it appears loose again re measure
this would rule out chain stretch at least and maybe point towards sprocket or somehting

[Lainie]

Thanks guys and yeah Rotaboy its a good idea will do that today

[Neka79]

some good points....
1.new chains DO stretch for a while, then settle
2. was it a good quality chain or a cheap one?? x/o/w ring??

another thing i thought of (how many km on bike??) the rear sprocket was mentioned, but have u checked the front sprocket is running true/not sloppy??