As per the title - giving the bike a pre season once over I noticed the chain was uber slack. Taking out the swingarm end caps I could see the reason for this was quite apparent because the eccentrics had moved/turned from where I had pencil marked it last summer. The RHS pinch bolt was pretty tight, I don't like to apply massive force just in case I strip the thread but the LHS pinch bolt can only be tightened so far because the slot in the frame is closed up. So how about I file/grind a little off each side of the slot to allow the bolt to be tightened up some more - Yea or Nay?
Might you have bent the parts of the frame where the bolt goes through at one side and screws into the other? If so while you can file the slot, if you tighten it again will it not eventually pull the parts off the frame?
The eccentrics are brand new items installed during it's recent refurb and I can't see where the frame might have been bent to cause an issue. It's almost like the eccentric is too small in diameter or it's mounting 'hole' in the frame too large a diameter. I've had the bike for years and from what I can recall the LHS may have always been like that. In the best traditions of Ducati I'm now thinking its a Friday afternoon frame & perhaps I could shim around the entire diameter of the eccentric??
I would put money on the left (top photo) has been overtightened in the past, pulling the part under the bolt head inwards. Make sure its not cracked as @Pete1950 has suggested
Many, many, many years ago I had a similar problem on my 900SS, I found the same on my 250 Desmo.. No cracks in the frames but the 2 sides of the joints meeting before they were tightened onto the spindles. I used a slitting disc and angle grinder to carefully open out the slots...Job Done and no problems ever since. Steve R
As I say I've had the bike 40 years so that may have been me when I first had the bike and little mechanical acumen. Although I do seem to think I have always had the same trouble with that side. There's no obvious crack on the outside and I don't fancy taking apart him at the moment to check on the inside. I have however noticed the gap at the bottom of the slot is greater than the gap between the bolt retaining lugs. It's almost like the lugs weren't welded on 'square'
Well there was no way I could have got a slitting disc in there with it all in situ so I bought a fine tooth hacksaw blade and did it by hand with (just) that. With a brand new sharp blade it didn't take that long to cut a sliver off so, hurrah! we now have a decent gap with it unclamped & clamped. I'll see how we get on when put I some fresh oil in him & fire him up for the summer in a couple of days... just in time for the forecast rain no doubt...
