FRONT SPROCKET

[Crusher]

Hi everyone my front spocket has a play of at least 1mm going forward on the spline and about 3mm sideways on the shaft, so my question is what play if any is there on the spline as my manuel is not clear on this and as the outside of the sprocket is more than ok, being that the teeth r only just wearing on the front face of the sprocket I did not c the need 2 replace it due 2 the outside condition of it. So I find it strange that the wear is not consistent or is this normal as im new 2 owning a duke and hence ive only just brought this bike and my bad as I did not look carefully enough as love is blind But the good thing is its winter the bike is in bits a new manifold on its way from USA thanks 2 Wilbur, swingarm modifiyed 2 fit new tyres, new filters from aussie 2 fit those lovely flatsides, oh the joys of owning areal bike Time 4 a

[ducinthebay]

The countershaft sprocket always has a bit of free play in it. You should take it apart, and clean the parts occaisionaly. Confirm that the retainer plate is in good condition and doesn't have grooves in it. It is a cheap replacement part from Ducati and same as many other models. The shaft and sprocket should be clean and have a very thick grease in between the two. This will keep the rust down, and will also act as a cushion between the two parts for a long life. The shaft is much harder material than the sprocket, so if there is too much play, get a new sprocket. Use Loctite or some other thread retaining material on the small bolts that hold the retainer plate.

Cheers,

[Crusher]

Cheers for that

[silverfox]

This started as an experiment 3 years ago and its still there.

Those clips are a joke, and the sprockets are too thin to stop it from moving.

This is what I did, get an old sprocket and cut the outside off all the way round.
Weld it to your new sprocket - now the splined centre is double the original size.
The centre of the shaft has a threaded hole, you can use this to bolt a retaining plate and to the two bolts in the sprocket. The toothed part of the sprocket is in the same place on the spline as it was with the old system BUT NOW ITS "ROCK SOLID"



It looks ugly and I haven't got round to making a better looking outer plate but it works perfectly.

Tony

[Tamburinifan]

NOW ITS "ROCK SOLID"

Does that mean there`s no freeplay whatsoever?

[silverfox]

I'm sure there is a small amount of "flex" in the outer plate.

I don't see a problem if the front and back sprockets are in line - the chain has some movement anyway.

The more surface area on the spline the better..............


Tony

[ducinthebay]

As long as you have the welder out, you may as well weld the outside retaining plate on there too. Less bolts is better. Just get a good thick SAE washer that fits the center bolt well, and weld it on.

This is the same method of moving your chainline outboard a bit if you modify your bike and run into a conflict of the chain and the rear tire. My 750 Sport had a similar set up when I got it.

Be very careful of tightening that center bolt and putting loctite on it. It is prone to back out. I put a lock washer and loctite on mine after I found it half backed out several times.

Cheers,

[Tamburinifan]

Just an amateur, but,
Duc engineers experienced a little freeplay is good f softening engine pulses,
output shaft durability, gearbox etc.

Just asking, isn´t a little freeplay necessary??

[ducinthebay]

Gert,
Good question. I don't know why the Ducati engineers chose this method. The newer Ducati's have a big nut that tightens down on the sprocket just like most other bikes. I don't know of another bike or brand that does it the way Ducati did, with a retainer plate. On the other side, I have heard of a few failures of the retainer plate, but I have seen the same with a big locking nut too. So I don't know of any distinct advantage, except in racing where you may want to change it easily.

Cheers,

[silverfox]

How does having sidways play in the front sprocket "soften the engine pulses"

Surely thats why you have a rubber mounted rear sprocket.


Tony

[DaveM]

" I don't know of another bike or brand that does it the way Ducati did, with a retainer plate. On the other side, I have heard of a few failures of the retainer plate, but I have seen the same with a big locking nut too. So I don't know of any distinct advantage, except in racing where you may want to change it easily. "

honda use a retainer plate as this is the sprocket retainer from my son's 350 honda ! well worn out

[Desmo_Demon]

I had an issue with the retainer wearing out on my ST2. This had the sprocket walk toward the engine, what was left of the retainer chewed the end of the transmission output shaft, and the sprocket finally stopped where the splines flare out, fortunately stopping the chain and sprocket from chewing into the engine case.

This is the chain over to the one side of the swingarm protector....



This is sprocket further down the shaft than it should be...



Here you can see how the ends of the spines are a little chewed up...



This is what the sprocket retainer looked like...




In an effort to try to fix the freeplay that is now exaggerated, I came up with this arrangement....

Just an amateur, but,
Duc engineers experienced a little freeplay is good f softening engine pulses,
output shaft durability, gearbox etc.

Just asking, isn´t a little freeplay necessary??

Eventhough others have had success with similar retaining systems as above, mine does not work. The pulsing was loosening the retaining bolts for the clip AND loosening the bolt in the shaft. I cleaned and used blue Locktite on all the bolts, and it STILL loosened them all up. Then, I safety wired all three bolts, and it BROKE the safety wire FOUR times. I eventually went back to the original OEM retainment system with the clip and haven't had an issue. It's a shame, too, as I was really hoping my new system would work.

[silverfox]

Mine has never come undone.
I wonder if you get tooooo much movement (still only have one thickness of sprocket spline ) between all those plates that causes the bolts to unscrew/break wires.

Tony

[Desmo_Demon]

I wonder if you get tooooo much movement (still only have one thickness of sprocket spline ) between all those plates that causes the bolts to unscrew/break wires.

I was figuring since the bike is nearly 100% ridden in the mountains, maybe all the back-and-forth between acceleration and deceleration was acting like an impact wrench. I was a little miffed when the bolts came loose after applying Locktite on them, but I was completely shocked when the bolts came loose with Locktite AND the safety wire broke.

[Tamburinifan]

On my Monster, 2 of the rubber inserts in the rear wheel f the sprocket carrier just escaped w/o any notice.
Could that have happend to your rear wheel?