I have had my 748 now for three years and have done many chain adjustments, but have always wondered if I have been doing it right.
I have been told that I should adjust my chain while the bike is on the padock stand, were others tell me that I should adjust it whilst the bike is on it's side stand.
As I understand it there should be about 1" of play at the tightest part of the chain.
When should there be 1" of travell? because if I adjust the chain on the padock stand, when I take it off the chain goes tighter, if I adjust the chain when the bike is on the side stand, when I sit on the bike it goes tighter still.
I would of thought that there should be an inch of playin the chain when the person who is riding the bike, is sat on it.
yeah chain adjustment is somthing i can never really quite grasp either, i kinda just get a feel for how tight it is when it comes back from service and try to keep it at that with the odd minor adjustment now & then and hope that its about right
I guess the manual will tell you to adjust the chain whilst the bike is one the side stand, as not everyone wants to go out and buy a stand.
The amount of slack is measured at a midpoint along the underside of the swingarm. I think the bikes came with a sticker marking this point???
Anyway...the chain should have about 25mm of play at this mid-point. When it is then stood upright, and the suspension sinks further, the chain tightens more, and when the rider gets on...it tightens still further.
But if you had the right amount of slack when it was on the stand, then it shjould be correct when the rider in on the bike also.
I was always told thast Ducati 748/9** like the chain too loose rather than too tight?
Also note that when you do adjust your chain, you are immediately adjusting your ride height also due to the eccentric hub...this is unavoidable.
If you like how your bike handles now, make a note of the ride height before fiddling!
Stick it on a paddock stand find any tight spot mark at 90 degrees on the tyre or wheel
(its a bit difficult to explain but make the mark at the bottom of the wheel/tyre in a direct line with the axle)
drop the bike back down and line the mark up again and sit on the bike then check the slack it should 25mm or thereabouts if not adjust it on the sidestand .
there is no point checking the slack if your not on the bike because the slack is only important when your riding the bike . if you adjust it when not on the bike you will make it too tight !!
As a chain wears it stretches and gets longer, but it doesn’t necessarily stretch the same amount at each and every link. So, in order to adjust the chain freeplay you first need to find the portion of the chain that has worn and stretched the LEAST. You need to rotate the chain and check its slack in at least three different sections.
Every 600 miles or so, put the bike on a paddock stand and find the tightest section of chain (least droop between sprockets) by turning the rear wheel in neutral. Measure the amount it droops from the bottom of the swingarm to the lower edge of the chain. The droop will be largest at a point equidistant between the sprocket centerlines (see swingarm label.)
If this measurement is LESS THAN one inch (25mm) the freeplay should be increased. The concern here is that the chain is adjusted too tight rather than too loose. A too-tight chain will lock-out your rear suspension movement and load the chain in excess of its tensile load rating. Drive chain tensile ratings are matched to the bikes power by the manufacturer, but this tension can easily be exceeded if the chain is installed too tight. Specifically, a number of chain failures can be traced to chains that have been adjusted too tight.
Just as a reminder, before you adjust the chain freeplay, measure and record your rear ride height so you can reset it.
Ducati's specification of ONE INCH MINIMUM is directed at preventing the chain side-loading the transmission output shaft bearings when the swingarm moves upwards during the bike’s acceleration, or after hitting a bump.
The chain is as tight as it can get when the centers of the front sprocket, swingarm pivot, and rear axle are all in a straight line. This only occurs when the bike is dynamically or heavily statically-loaded. The slack adjustment spec on the swingarm plate assumes that the bike is unloaded.
Even at one inch it’ll still be tighter than many other manufacturers' recommendations. Note that Ducati doesn’t specify a maximum distance, so a 1-1/2 inch droop here would not be excessive. Not having enough freeplay is a recipe for chain failure.
This is also the time to clean and inspect your chain for any links that are unusually stiff, which indicates binding from lack of internal lubrication or corrosion caused by link o-ring failure. Also check for any link side-plate damage caused by road debris that may have gotten wedged between the chain and sprocket.
Finally, keep a trending record of any adjustment that was made.
A chain should be replaced when it has stretched excessively. Each link in a new 520 or 525 pitch chain measures 15.875mm (5/8-inch) so 16 links will measure 254mm. When a 16 link section of an o-ring chain has stretched to 257mm (under a 20Kg/44lbs load) it needs to be replaced before it fails. When a Ducati chain snaps, it will often wedge between the drive output sprocket and the engine case, destroying the case and hopefully not locking the rear wheel in the process.
Chain stretch across 16 links can be checked with calipers by first placing the transmission in gear and then rotating the back wheel so as to tension the upper strand of the chain.
05-Sep-2005, 20:50 
Shazaam!
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