Gearset Noise or not ?

[2taddict]

My bike bike has picked up ( what I think ) is a gearbox noise. I changed the front sprocket as I thought it was the chain slipping. The sprocket was well worn when I bought the bike but the noise is still present mainly when the engine is under load in 3,4,5 gears.
Anyone had this problem with their ec300. Mines an 06

[Jakobi]

What kind of noise are we talking?

[2taddict]

Originally Posted by Jakobi

What kind of noise are we talking?

Hi Jakobi.....It sounds like the chain is slipping (clunking) over the front sprocket when powering on but it shouldn't be as both sprockets are now new and the chain has correct tension.
Some have said that it may be the chain against the swing arm but I've never experienced it on any other bike before.
It doesn't seem to be loosing power therefore I've cancelled the clutch out so I was wondering if anyone has had this happen and what's the cause.
Cheers.

[Jakobi]

I've had chain slap before when pulling a gear too high, but its usually only at low rpm, under load. Can't be felt, but most definitely can be heard.

Any contamination in the gear oil or stuck to the magnet? Does it happen all the time or just sometimes?

[2taddict]

Originally Posted by Jakobi

I've had chain slap before when pulling a gear too high, but its usually only at low rpm, under load. Can't be felt, but most definitely can be heard.

Any contamination in the gear oil or stuck to the magnet? Does it happen all the time or just sometimes?

There was some slight contamination on the magnet but nothing too dramatic.
I've been going through this site and the more I read the more I'm thinking chain slap and as you say "only when pulling a gear too high, at low rpm, under load".

Its been said in another post that its a characteristic of the bike, so I'm probably worrying about nothing!

Thanks.

[Jakobi]

I would describe it as a clacking/chattering sound. Little bit more chain tension should reduce it. Sometimes the chain slider will slap against the swingarm too. In this case a bit of rubber/silicone/double sided tape can dull the sound.

[2taddict]

I'll see how things go, I can live with it not a problem if its just chain slap, I wouldn't mind knowing for sure though just for piece of mind.

Might spoil it with new chain, plus slides & guides I have spotted on 2T Racing web site.

[Neil E.]

Originally Posted by 2taddict

the noise is still present mainly when the engine is under load in 3,4,5 gears

You are hearing chain slap on the swingarm. If you operate higher in the revs the noise will go away. I put 2mm closed cell foam tape under my chain slider and it eliminated the noise. Basically the rattle is telling you to shift down so the revs will increase.

[2taddict]

Just an update on what I thought may have been a failing gearbox.
I ran a bead of Sikaflex polyurethane under the chain slider and tightened the chain slightly and the noise has completely gone. Phew, It really sounded like something horrible was happening inside the tranny and not just the chain guide slapping against the swing arm. So anyway, all's good and very happy. Thanks for the advice guys.

[Jakobi]

Good outcome.