Hi just fitted a new chain and sprocket set and now when I accelerate, on part throttle I get a weird noise like a ratchet or clack clack noise is the only way to describe it? Anyone ever seen or heard this? any ideas what it could be? I think it may have been doing it before the chain swap but i did not ride it much and put any noises down to the chain being shot?
Thanks
Jack

Check the chain is the correct tightness.

If it particularly happens at low revs in higher gears - it is normal. It's just the engine complaining about being asked to work harder than it thinks it should at those revs . Try the same procedure in a lower gear and you should find it's fine.

If not, try to say more about the symptoms.

The chain does thrash around a bit on off road bikes. It may be slightly slack but that is much better than being too tight.
When you are riding with off road bikes look at their chains whipping about I think that will explain the noise to you.

Jack, sorry to have to ask this , check all fasteners you released.
Have you altered the gearing in the swap set.
As mentioned previously, check chain slack.
Also, from memory, you purchased a Non O ring chain, which can rattle about more due to not having the damping effect of several hundred O rings.
Mike

[quote="fallenmikethebike"]Jack, sorry to have to ask this :roll: , check all fasteners you released.
Have you altered the gearing in the swap set.
As mentioned previously, check chain slack.
Also, from memory, you purchased a Non O ring chain, which can rattle about more due to not having the damping effect of several hundred O rings.
Mike[/quote]

Hi Mike Funny enough I was just thinking about the gearing, it has gone back to standard and before it had a much bigger rear sprocket and a 13 tooth front, so it was down geared quite a bit! I will check the fasteners tomorow, but first proper ride out today with a guy from the throttle monkey site, in wales CRM`s are top, excellent trail bike!

Jack it really sounds like your chain is too loose, when you are tightening the chain make sure that there is someone sitting on the bike so you can see how tight the chain is when it has someone on the bike. Hope it makes sense!
Jonty

You have raised the gearing massively and are getting the effect as described above. Just use 1 maybe 2 gears lower than you previously did. You may end up thinking that the 'new' gearing is very much too high for off road.

knackeredMk1 wrote:You have raised the gearing massively and are getting the effect as described above. Just use 1 maybe 2 gears lower than you previously did. You may end up thinking that the 'new' gearing is very much too high for off road.

yep +1.
Mike

[quote="fallenmikethebike"][quote="knackeredMk1"]You have raised the gearing massively and are getting the effect as described above. Just use 1 maybe 2 gears lower than you previously did. You may end up thinking that the 'new' gearing is very much too high for off road.[/quote]
:D yep +1.
Mike[/quote]

Hi I checked tonight and I appear to have got everything on correct, does the front sprocket have the writing on the outside, as in 14 should be readable when the cover is off? I adjusted the chain, it was quite slack and if I spin the wheel it is quite noisy just by hand, what gearing do most people run? I still ride the bike to the trails but its not my comuter or anything?
Thanks

13:45 is quite common.

14:40 is stock and what you have

I run 14 /45, Jack, check the wheel alignment, not on the snail cams, but with a long straight edge, from front wheel to back, as they do for the MOT.
If the wheel is seriously out of line, that will give the noise you can hear,as the chain chaffs against the sprockets teeth, as will, getting the spacers muddled, and in the wrong side, ask me, I know.
Mike

[quote="fallenmikethebike"]I run 14 /45, Jack, check the wheel alignment, not on the snail cams, but with a long straight edge, from front wheel to back, as they do for the MOT.
If the wheel is seriously out of line, that will give the noise you can hear,as the chain chaffs against the sprockets teeth, as will, :oops: getting the spacers muddled, and in the wrong side, ask me, I know.
Mike[/quote]


Hi Mike, I will check the wheels tonight, and I think I will try the 45 rear
Thanks to all the replies.

Hi checked the wheels and all looks fine, my mate came round, he`s a bike mechanic and took the bike out and said its just the chain flapping around on part throttle, when your on full throttle the chain does not flap about so much, got the rubber from the rear chain guide arriving soon so hoping this will maybe quiet in down a touch.
Does the front sprocket go on with the boss facing outwards or in towards the engine?
Thanks
Jack