14t mod + chain noise.

[Chris & Nean]

I did the 14t mod, it all went smoothly, but I can now hear a winning noise that I think is coming from the chain, it sounds a little like the winning that occurs when a chain is overtight but if I pull the clutch it goes away, it may even be the clutch making the noise for all I know but I don’t remember hearing this before I changed the drive sprocket from 15t to 14t, does this mod come with a slight increase in noise from the chain? Any thoughts on this plz folks.

[bigredduke]

Isn't the 14t standard & the 15t a mod? Methinks you may have it the wrong way round old chap!

[Chris & Nean]

naa bigredduke, I got it round the right way, it is correct that Ducati send us their Monsters with silly overgeared 15t sprockets, but I would love to know if any extra strain putting the chain round a one lesser tooth sprocket leads to additional noise, so I can ignore it and enjoy the bike and not worry anymore.

[Pedro]

The noise is probably the chain running over the plastic swing arm protector... nowt to worry about provided the chain is properly adjusted.

[russ77]

Might be a daft question, but is the bike off the rear stand? When I changed to a 14T sprocket, I adjusted the chain and started the engine, put it in gear to just check that nothing was going to fall off. With the characteristic lumpy delivery of a V twin, combined with the lack of resistance and the swingarm being at its lowest point, the chain clatterd about quite a bit. Nothing to worry about as this goes once off the stand.

If you've already taken it off the stand and it's still making noises, I'd agree with Pedro. The reduced diameter of the sprocket means that the chain will rub a bit more on the plastic swingarm protector when under reduced load. Double check the chain tension and wheel alignment and enjoy the mod. I did.

[Chris & Nean]

Yep russ the mod is great, much more control around street corners and small road islands ect.

I can easly see the point about the chain making noise running over the plastic guid, I did check and check again that I got the 31 mm free play on the chain and this amount of slack really looks loose to me, i can imagine it flapping around lots if the bike was run on the stand, maybe its just me getting used to the bike and starting to hear noises that didnt used to bother me before, I got 600 miles on it now and so far it aint missed a beat :D

[bigredduke]

naa bigredduke, I got it round the right way, it is correct that Ducati send us their Monsters with silly overgeared 15t sprockets, but I would love to know if any extra strain putting the chain round a one lesser tooth sprocket leads to additional noise, so I can ignore it and enjoy the bike and not worry anymore.

Silly me! I'm easily confused!

[Rockhopper]

You want to make double sure that the chain isn't too tight as you will quite quickly damage the gearbox output bearing if it is.

[Chris & Nean]

Yes Rockhopper I read about this need for spot on chain adjustment because of the output bearing being a bit fragile, that was my concern over this noise I could hear, but I did adjust the slack to 31 mm as the manual instructs, and this slack can be checked using one finger and very little effort to get the chain moved through this dimension, its an S2R and its actually possible to push the chain up until it makes contact with the back end of the bottom chain guide (this is with the bike on the side stand) does this sound right? and if so could it be a second method of checking the slack, wadya think? Or have I got it too loose.

[russ77]

... I did adjust the slack to 31 mm as the manual instructs... (this is with the bike on the side stand)...

Remember that's 31mm from top of travel to bottom, measured half way along the chain between the two sprockets. Stand a ruler on the floor and push the chain up as far as you can with one finger, then push it down. Measure between the two points. Rockhopper's right that a chain that's too tight will cause more trouble than one that's too slack, within limits.

Measuring chain tension on the side stand is fine. If you've got an oldskool swingarm, you should check alignment at the same time, for which you would need a rear stand. If you've got an S2R though, this isn't an issue, you lucky so-and-so.

[gremlin]

if its of any use, my hubby changed down a tooth on the front sprocket on his fazer thou and it made a hell of a lot more noise, when he checked with the owners club they all said the same. the noise is like the chains too tight, but is caused by the fact that the chain is turning at a tighter radius and so the links move more creating more noise. but he has noticed that it has quietened down since putting a few more miles on it and constant wheelying helps it bed in quicker:thumbsup: :thumbsup:

[Chris & Nean]

Umm gremlin this sounds about right, it makes sense that pushing the chain round a tighter rad’s going to make more noise, I hope it does quieten down with use but I aint going to try wheeling it lol. I was at the shop yesterday russ and I took the opportunity to go round all the bikes trying the chain tensions, they all seemed a little tighter than I had mine set and were all consistently adjusted as u would expect, I tightened my chain up just a touch to mirror what I had seen.

[lcjohnny]

I think part of the noise is due to the fact that our "renolds -chain" type sprockets are not effectively round. They actually work as a series of 14, 15 or whatever flat sections one where each of the links of the chain sits over a tooth of the sprocket.

Because the shape is a polygon and not round, the radius from the centre of the shaft to the chain as it leaves the sprocket varies as the sprocket rotates. The less the number of teeth the more the proportional change in radius and the more vibration in the chain. The concept becomes clearer if you think of a 4 or 3 tooth sprocket at the ridiculous end. (but I don't think it works for a 2 tooth or one tooth sprocket :chuckle: ) Apparently Hy-Vo chains run with much less variation in the radius and hence can be smaller and run at higher velocity


Anyway I remember reading that 13t is the recommended minimum size for power transmission sockets due to this factor. So I reckon the 14t is just getting a little too much cyclical variation and this is causing the whining noise.

What do you reckon? Jon

[jerry]

I had a 14 tooth on the S4 , noisy as old chain was too small 520 and alloy rear sprocket , now putting anew 15 front and 43 rear with proper 525 X ring chain , bike will be more geared down but very flexible at low revs and midrange , will probably only get 130mph out of it , but in the real world thats enough.

jerry

[Chris & Nean]

Today was the first chance to get out after all the snows melted, my chain is noisy as hell now after I tightened it up a shade (its tensioned exactly like the bikes in the shop at Coventry are like I was talking about, its 31 mm and easily moved through this dimension with one finger) I’m thinking this extra noise that its making now cant be good for that output shaft bearing in the gearbox, my chain was defiantly to loose before but now its not loose and its making a horrible noise, I’m beginning to wish I had not bothered touching the front sprocket at all and had changed the back one instead. what No. of teeth on the back would I need to get the same effect as going down 1 tooth on the front and if I did put the 15 tooth front sprocket back on and with a bigger rear would I need a longer chain? I cant put up with this noise, I must get this sorted plz tell me what to do.

[Chris & Nean]

130 is plenty Jerry

[Pedro]

Chris,

a thought... are the front and rear sprockets properly lined up? I seem to recall that someone on here found that bikes of a particular age had slightly different sprockets to all the others, which made the chain run at an angle between front and rear sprockets. It would certainly explain the chain noise

[Chris & Nean]

There was no chain noise at all the way the bike came from the shop Pedro, its new, I picked it up in the new year, its an 06 bike, it came with its standard 15 front and whatever rear sprocket. Your input is the first I have heard about any alignment issue, I doubt it relates to my bike because it was fine before I put the 14 tooth front on (but then again it’s a mod and anything’s possible I guess), people have stated above that extra noise is common with this mod, I just cant get to grips with a whine from the chain sprocket combo when I know there’s an issue with the durability of the output bearing in the gearbox, I would rather swap to a bigger rear sprocket and even if it means having to get a new longer chain, but when I had the chain adjusted extra loose the noise was much lessened, I’m going to loosen the chain again and see what I think.

[Pedro]

Doh, just spotted you have a new one!

I tried the 14 tooth thing last year, mainly for the track day, but hated it on the road on my 900, far to buzzy if you ask me and a flipping wheelie nightmare! It also sounded noisier I think. Have you checked the chain tension while your sat on the bike? This should show how much slack you have at the worst case. The other thing to check would be if the chain has a tight spot anywhere or has been stretched unevenly. this might make things noisy.

As for adding teeth on the rear, you probably want to go up two or three teeth to get the same effect as the 14 front.

[Chris & Nean]

The thing you mentioned about being sat on the bike Pedro, I adjusted the chain to recommended spec with it on the side stand to 31 mm free play. Today I took my wife out for a ride combined weight 22 stone I’m 12 (she wont disclose her weight lol) I did take my eldest son a ride a few days ago and he’s a real big 17 stone guy and the chain was quiet (I had it adjusted then at an extra loose, maybe 35mm) no noise, but today it was very noisy after I tightened it up abit, I will adjust the chain again to try to make it quiet but I will not ride around with it like this making lots of noise, something’s wrong with the set-up like this, it cant be good for future longevity to use the bike if its making mechanical noise like this.

[Scotty]

umm i like a slack chain after an 'unfortunate' incident

also it is possible to put the front sprocket on back to front (as i have done in the past)

[Jez]

Now I just tightening my chain over the weekend on a pit stand (the bike,not me) Took me a few goes to get it right, and I am sure it is. On the swing arm (M620ie 2003) it says 27MM of slack. But I rode the bike for the first time this moring and I have the whining noise. I have not done a sprocket mod (although that sounds like a great idea!).

Incidently, when I tensioned the chain, and by only a small amount, when I spun the rear when the chain went from the right slack to being very tight. How the hell!!
:-o
BTW I did end up with the 27MM of slack after spinning the wheel a few times and on inspection once I arrived at work it still seems to have an OK amount. Not to tight, not to loose...just the way I like it in fact ;-)

[nambduke]

Incidently, when I tensioned the chain, and by only a small amount, when I spun the rear when the chain went from the right slack to being very tight. How the hell!!
:-o

Your chain needs to be adjusted on the 'tight' spot. All chains wear unevenly. If you adjust on a slack point, the danger is your tight spot becomes too tight with the potential of snapping!

If you can't adjust within sensible limits, it means you need a new chain and sprockets!

Regards,
Mark Nambduke