Hey there. On the way to work this morning, I noticed (and felt) a knocking noise coming from the left hand side of the bike. When I speed up, it gets faster, and vice versa... My logical conclusion is either gearbox or chain. I had a good look at my chain and noticed a slight bit of rust on the side of it. Chances are the salty winter has gotten grips with the bike. I've seen a new chain on the nets for around £25 (heavy duty one) But are there any other possibilities that may cause the knocking noise. It's almost certainly not the bearings, as I had them checked out about 2 weeks ago when the bike went in for a Winter Checkup. Cheers in advance Tom
Yeh, chain is tight, but with a hint of flex in, as it should be. If it's any help, when I tried to turn my wheel when pumping my tyres up yesteday (centre stand, and bike in neutral) it was rather stiff. Could that be any help to you?
Is the chain too tight, have you got the correct amount of freeplay in it, is it well lubed? you might have a couple of tight spots in the chain. Pop yer bike on the center stand, rotate the wheel until you find the tightest spot in the chain, then mesure the vertical freeplay and adjust acordingly.(The correct amount should be found in your handbook/haynes manual or by a sticker on the swingarm) If your running around with the chain too tight it can damage the output shaft and bearings then you would get knocking noises. Same goes as if the chain is stretched or full of tight spots you would need a new chain. Hope this helps dude. :thumbup:
Yeh, I'd put money down saying it was the chain, as I can see some rust on it. I'm going to take a trip to Seabank tomorrow and ask how much it'd be for a new chain. I can get one myself for £25 ish. Just don't have the knowledge to fit one. The chain isn't too tight, I've wiggled it around and it's got about an inch/inch and a half of play.
if the chain is too tight it will make knocking sounds also it will make simialr sounds if too loose go for around 20mm of play at the slackest point if you have adjusted it lately have you correctly aligned the rear wheel on the blocks ? has this been tighten up correctly a fair few things to check mate before you even get to the engine noises !
I had my winter check done by Aprilia Merseyside (On rake lane, Wallasey) I've known the guys for a good year and a bit, and they aren't exactly pikeys. I trust they have adjusted everything fine. So far as I can see, the "knock" happens every wheel rotation and a 5th... I also just noticed that I have a sh!t load of oil on my rear tyre. Only on the chain side... funnily enough?
Remove stone from tread on wheel that knocks, sorted. Suspect bearing? But that would grumble not knock.
Oh yeh, that was sorted with an inner tube last year. I was making sure my tyres were still at the right pressure
new chain = new sprockets new chain on old worn sprockets isent a good thing as the old chian as meshed with the sprockets and can f@@k the new chain up fast :thumbup:
oil or chain lube? does it knock if you just push it forward and back in neutral? (or even better on a stand) is there any sign of oil from the front sprocket?
There's a smidge of oil (chain lube, it looks like, really thick) on the sidewall) The other oil around the place was just all the crap in the roads from when the dew lifted it up. Yeh, knocks when in neutral and coasting. It's quite difficult to turn the wheel once I hit the tight spot. No sign of oil from the front sprocket, the only oil there is seems to be from the chain. Thanks for the help, guys.
Take it back to the peeps who serviced it and get their advice, and post it up on the forum for more opinions before parting with your cash.
id deffo say its the chain. should be easy to turn the wheel. may free off ok for the time being if you rub a load of oil onto it with a rag. pal of mine only uses a heavy engine oil or gearbox oil. wont use chain lube. get it nice and soaked, then wipe off all the excess. may free it off till you can replace.
Regards the tight/stiff back wheel,in my opinion the chain is too tight. As what you ar describing is generally caused by a tight chain. Most rear sprockets are not circular they have high and low points, this is not obvious when you look at it. Therefore if you tighten the chain without taking four reference distance readings (chain play) you could over thighten as you might be measuring the low point on the sprocket. I recently changed my chain and sprockets as the old chain was knocking due to peaks on the chain.
rear sprockets are not circular surely this is not true? :w00t: chain's have tight spot's not sprocket's, you adjust the chain at the tightest point in my experience. :green:
The backlacker and syrinjon valve are always items which need looking at especially on a 125. Sprocket - I was led to beleive that they are slightly eccentric, could be wrong I was told by a blind man
