Knocking/Rattling @ Front Sprocket @ Low Speed in 1st & 2nd

[ViniH]

Since this morning I've noticed an odd noise and feeling from around the front sprocket area.

The chain seems to be bouncing around more than it should and it sounds and feels like it is knocking/catching.

At first I thought the tension had dropped too low and it was catching on the raised centre stand, but I adjusted the tension and to improve clearance and the problem remains.

I took the sprocket cover off and it was absolutely filthy inside, but I didn't see anything obvious that might cause it - when I rotated the wheel everything seemed normal to my [extremely novice] eye.

I gave it a good clean and put the cover back on but it's still happening.

It seems to only occur at low speed in low gears, once I get up to about 25-30mph and/or shift to third it seems to stop - and at higher speeds on the motorway it sounds and feels completely normal. The lower the speed and gear the worse it is, at very low speeds (<5mph) in 1st it feels quite bad.

I thought maybe the bearings were going or something, but there seemed to be no play in the sprocket when I tried to waggle it.

Anyone have any ideas before I drop it into a garage?

[teejayexc]

Check the retaining nut on the front sprocket, they have been known to come loose. There should be a tab washer bent over to hold the nut on, don't take it for granted that if it's present it's ok....stripped threads within the nut retaining the sprocket are not unheard of.

Check this first and give it a clean up in there too.

[Deleted]

Mar 13, 2014 8:30:27 GMT @ori said:

Mar 13, 2014 7:58:35 GMT teejayexc said:

Check the retaining nut on the front sprocket, they have been known to come loose. There should be a tab washer bent over to hold the nut on, don't take it for granted that if it's present it's ok....stripped threads within the nut retaining the sprocket are not unheard of.

Check this first and give it a clean up in there too.

Did you purchase from a chap near Wantage?

[ViniH]

Looks like whatever I did when cleaning it has resolved the issue. It was smooth as you like this morning at all speeds in all gears, it's actually better than it's been before, which makes me wonder if something was loose after the chain was replaced.

[CD]

Check the front sprocket anyway. If it is loose, it will fret and damage the shaft.