Chain and sprocket measurement - how to?

[mchaggis]

On my shitty little Chinese 125, I need to replace the chain and sprockets. The 'Operation Instruction' doesn't go quite as far as actually saying what the chain is, or even any instructions regarding it at all.

I wouldn't care that much other than the fact I gave it to my sister for nothing and I'd rather she didn't come to harm as a result of the chain getting too slack. There's very nearly no adjustment left and this winter will very certainly finish it off. I'd rather replace it before that happens.

Is there any way for me to take my Vernier callipers and measure the chain and perhaps sprockets to see what they actually are? I have the idea that it might be either the CM125 or CG125, but I'm not especially willing to put out £40 on the off chance of getting the right one. (And yes, my sisters's life means more to me than that... )
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Mmmm, Guinness
Discovering the delights of Hammerite and a 3/4" brush.

[gavin]

https://www.gizmology.net/sprockets.htm

[timjim]

You mention the bike being a Chinese 125...is that the bike make or just origin,what is the actual make and model?I have Autodata on my computer and it lists sprockets and chain sizes.

[timjim]

If its a CG125 its dimenentions are:
pitch=0.5
width =0.25
chain =112 links
sprockets are=15 front/36 rear
freeplay=10-20mm



Hope this is of use,if you let me know the exact make/model/year,ill dig out more details Tim

[mchaggis]

It's a Hongdou Classsic 125, also known as a Feiying and badged variously as 'Exqusite' and 'Exclusive'.
____________________
I must not be a troll...
Mmmm, Guinness
Discovering the delights of Hammerite and a 3/4" brush.