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Discussion Starter · #1 ·
Problem: 900SS/SP (1996) gets nervous at medium to high lean (well before knee down), most notably in LH corners, but not exclusively.

On three occasions it has given me two wheel slides on corners that I know well and can easily drag my knee on my Panigale. This thing just does not want to get down to decent cornering without trying to deck me.

On a recent ride, I noticed that with hands off the bike consistently pulls to the right. Whilst riding in a straight line the steering is turned slightly to the right. (You can see the top triple is not centered).

I have aligned the rear wheel using the string method and verified that the wheels are also aligned in the vertical plane. I am worried that I might have a bent frame or something like that. I am quite disheartened after all the work I have put into this bike. I just want to get it handling nicely so I can get down to some decent cornering.

Some additional background info: the bike always exhibited “unwilling” high lean behaviour but I first put that down to front forks that were way too soft for my rider weight. I since fitted 0.9Kg/mm Racetech springs and gold valve and an Ohlins DU235 rear shock. The shock is adjusted to the same length as the OEM and the forks are positioned to the same settings in the triple clamps as before. Front and rear suspension sag is nicely in the Ohlins recommended range. My tyres are new Metzeller Racetech RR. I think that the bike should at least handle some fairly decent cornering with this configuration, even if it is not perfectly set up. The fact that the steering is off in a straight line causes me great concern and is obviously the most probable cause of my problems.

How do I check or measure for a bent frame or something that causes the steering to be off?

TIA
 

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If the triple is visibly offset, that's not right. Apart from the condition of the tires, 900s have been prone to frame cracks around the steering head. As previously noted, loose steering head, wheel bearings in good condition, rear wheel alignment should be checked. Engine mount bolts torqued to spec. Previously wrecked?

Good luck.
Scott L.
 

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Problem: 900SS/SP (1996) gets nervous at medium to high lean (well before knee down), most notably in LH corners, but not exclusively.
Like Spacey, I'm no expert on this. However, I do also agree with him that checking the steering head bearings should be a first step to consider. Based on what you stated though, I don't think that is the root of your problem.


On a recent ride, I noticed that with hands off the bike consistently pulls to the right. Whilst riding in a straight line the steering is turned slightly to the right. (You can see the top triple is not centered).

I have aligned the rear wheel using the string method and verified that the wheels are also aligned in the vertical plane. I am worried that I might have a bent frame or something like that. I am quite disheartened after all the work I have put into this bike. I just want to get it handling nicely so I can get down to some decent cornering.
Using the string method should get your wheels in line, which *should* correct any wayward self steering issues. A tendency to lean to the right versus a neutral tendency to go straight is a definite sign something is not right.

There is a procedure in the factory manual to "center" the steering after a tire change. Accordingly, you are supposed to loosen up all the pinch bolts as well as the axle. Don't remove them, or loosen so much that things start sliding.

Then brace the front wheel against the wall (or a high kerb, which there should be plenty of in Dubai if it is anything like Abu Dhabi) and "bounce" the front suspension a few times. According to the manual this is supposed to get everything centered again. Once done, tighten everything to spec in appropriate order and go for a test ride.

Some additional background info: the bike always exhibited “unwilling” high lean behaviour but I first put that down to front forks that were way too soft for my rider weight. I since fitted 0.9Kg/mm Racetech springs and gold valve and an Ohlins DU235 rear shock. The shock is adjusted to the same length as the OEM and the forks are positioned to the same settings in the triple clamps as before. Front and rear suspension sag is nicely in the Ohlins recommended range. My tyres are new Metzeller Racetech RR. I think that the bike should at least handle some fairly decent cornering with this configuration, even if it is not perfectly set up.

TIA
Are your fork tops level with the top triple clamp? If not, I'd move them closer to that setting. Then I'd raise the rear about 5mm. That should eliminate your heavy handling or as you put it, unwillingness to turn. That said, I experienced what I call heavy handling on any number of Ducatis from the 1990s. When I say heavy handling, I mean it takes a heavy input to initiate a turn, but once there, stable like a stone edifice. No drama. No wiggles. Nothing but a feeling like "I could just take my hands off the bars and this thing would keep tracking where I pointed it"

The only "cure" I've ever read about, found on my own or seen on a video was more rear ride height. Assuming the front is as high as it will already go, that would lighten up the amount of steering input required. If it feels too nervous, I'd drop the triple trees about 5mm down the forks rather than dropping the rear back down.

I hope that helps. Check the steering head bearings. Do the centering procedure. Then see if it tracks straight and true. If it is still a bit heavy steering, raise the rear....or just live with the heavy steering. I honestly didn't really mind it once I was used to it.....sean
 

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What you have listed for mods should be working fine. As others have said you need to figure out why the forks are not centered in the trees. The forks can become "racked" after a crash but this should have been fixed when you had them off for fork work. If you loosen the tree bolts slightly you can some times align them by hitting the wheel on the side until they come back into alignment. At the dealership we had a telephone pole (remember those?) that we would use to smack the front wheel straight into alignment. The tire is what gets hit so contact with the metal happens.

Also do not forget to check the swingarm shimming at the pivot, if the swingarm is not shimmed correctly you can get swingarm shift when you side load the swingarm such as cornering. You should have zero side play on the swingarm at the pivot.
 

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Also do not forget to check the swingarm shimming at the pivot, if the swingarm is not shimmed correctly you can get swingarm shift when you side load the swingarm such as cornering. You should have zero side play on the swingarm at the pivot.
While you are in there looking for the shim stack and side play at the swing arm pivot, make sure to check the welds on the swing arm. I got a nasty surprise on mine:



This is on the inside of the swing arm. It was not visible at all from a visual external inspection. It only became visible once I cleaned up all the grime and old chain lube from the pivot area. The crack goes 100% of the inside weld top to bottom of the swing arm, 75% of the weld across the bottom of the swing arm and 100% of the way across the top of the swing arm. This was hidden under the chain slider so again, not visible under normal circumstances.

I cannot imagine the result of this failing while leaned over in a corner. Catastrophic failure at that point would land a rider on their head and sliding without a clue as to what just happened....sean
 

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Should not have the struggle in the turns as you describe on a 900SS - so it can be fixed.

Getting a new set of tires and raising the rear a bit more than the sag measurements called for cured that vague unsettled feeling at partial lean on my bike soon after buying it. I figure my being a heavier guy interfered with the rear shock sweet spot.

Pulling to the right is very wrong, there are some good causes to check listed above.
 

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Discussion Starter · #8 ·
Using the string method should get your wheels in line, which *should* correct any wayward self steering issues. A tendency to lean to the right versus a neutral tendency to go straight is a definite sign something is not right.
I totally agree. :crying:

There is a procedure in the factory manual to "center" the steering after a tire change. Accordingly, you are supposed to loosen up all the pinch bolts as well as the axle. Don't remove them, or loosen so much that things start sliding.

Then brace the front wheel against the wall (or a high kerb, which there should be plenty of in Dubai if it is anything like Abu Dhabi) and "bounce" the front suspension a few times. According to the manual this is supposed to get everything centered again. Once done, tighten everything to spec in appropriate order and go for a test ride.
Thanks. I am familiar with this procedure. (Yes, lots of high kerbs here too)

Are your fork tops level with the top triple clamp? If not, I'd move them closer to that setting. Then I'd raise the rear about 5mm. That should eliminate your heavy handling or as you put it, unwillingness to turn. That said, I experienced what I call heavy handling on any number of Ducatis from the 1990s. When I say heavy handling, I mean it takes a heavy input to initiate a turn, but once there, stable like a stone edifice. No drama. No wiggles. Nothing but a feeling like "I could just take my hands off the bars and this thing would keep tracking where I pointed it"
It doesn’t resist turning. In fact it turns in nicely. It behaves very well until you get to about 2/3 or 3/4 lean, about when the suspension starts loading up from cornering force, then it starts “talking to you”. My best effort to describe it is that it feels like it is starting to wobble, or pogo from front to rear slightly. This is on beautifully smooth road, for example a nice large radius roundabout with good grip at approx 60-70kph. If I get brave/aggressive and demand more from it, that’s when I have experienced two wheel slides, which so far I have been lucky enough to recover from.

I am not at home to tell you exactly, but the forks tops are raised about 17mm from the top triple. That’s where they were when I got the bike so that’s where I put them back to after doing the Racetech springs and gold valve. I could try adjusting fork height and rear height but that’s obviously not the cause of my wayward straight line tracking, so I first need to focus on solving that.

I hope that helps. Check the steering head bearings. Do the centering procedure. Then see if it tracks straight and true. If it is still a bit heavy steering, raise the rear....or just live with the heavy steering. I honestly didn't really mind it once I was used to it.....sean
Thanks for your input. I appreciate it. The steering head bearings are good. I will double check everything, including wheel alignment, then go from there. Ducvet mentioned the swing arm shims. That could be a good lead. I’ll write about that in another post...
 

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Discussion Starter · #9 ·
What you have listed for mods should be working fine. As others have said you need to figure out why the forks are not centered in the trees. The forks can become "racked" after a crash but this should have been fixed when you had them off for fork work.
What do you mean by “racked”? The bike has definitely been down the road. It turns out the nice Silmoto cans are not just there because PO wanted an upgrade. More like he was forced to upgrade after trashing the originals. (Tell-tale scrapes on the swing arm behind the pipe.) Seems like the bike has suffered some other damage...

If you loosen the tree bolts slightly you can sometimes align them by hitting the wheel on the side until they come back into alignment. At the dealership we had a telephone pole (remember those?) that we would use to smack the front wheel straight into alignment. The tire is what gets hit so contact with the metal happens.
I’ll check this out. It could be a winner.

Also do not forget to check the swingarm shimming at the pivot, if the swingarm is not shimmed correctly you can get swingarm shift when you side load the swingarm such as cornering. You should have zero side play on the swingarm at the pivot.
Another very good lead, thanks!
 

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Discussion Starter · #10 ·
While you are in there looking for the shim stack and side play at the swing arm pivot, make sure to check the welds on the swing arm. I got a nasty surprise on mine:

I cannot imagine the result of this failing while leaned over in a corner. Catastrophic failure at that point would land a rider on their head and sliding without a clue as to what just happened....sean
I have read about the dreaded swing arm cracks but never seen a picture quite as frightening as that. Good job you found it. Another thing on my to-do list (and to hope is ok). Thanks.
 

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My steering head bearings felt fine, but with no forks on them I felt just the tiniest roughness at dead center. I was very surprised to find the bearings were totally trashed at dead center and about 1/2” either way. I’m not as aggressive a rider as you, but still surprised at the damage I found. I remember when the bike was new to me I had to get used to the amount of input required to turn. Maybe the bad bearings contributed to that.
 

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By "racked" I mean if you look and the forks are not parallel with each other and the top and lower tree are not parallel either. It is not uncommon when the front end suffers a hit from the side end the tree's rotate out of alignment, the bolts being tight then holds the forks in this position. Loosening the pinch bolts and re-aligning things before tightening everything back up usually makes it all right again.
 

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Discussion Starter · #13 ·
By "racked" I mean if you look and the forks are not parallel with each other and the top and lower tree are not parallel either. It is not uncommon when the front end suffers a hit from the side end the tree's rotate out of alignment, the bolts being tight then holds the forks in this position. Loosening the pinch bolts and re-aligning things before tightening everything back up usually makes it all right again.
I understand now, thanks. It’ll be the first thing I check because it could explain everything.
 

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undo everything except the lower triple and remove the calipers. slide the upper triple off and try to refit it. if it won't go straight back on or things look out of line the lower triple is bent.
 

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It’s usually the stem that bends at the lower clamp. Out of the very many bikes I’ve repaired the stem is the usual culprit. If not kinked then it will straighten which a few belts with a lead mallet. Losen the axle and pinch bolts them pull up the top clamp up until it comes off the stem and if it’s not centred when you push it down the the stem or a fork is bent. While your at it check the bearings for notches by unloading the front and turning the front left to right.
 

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My steering head bearings felt fine, but with no forks on them I felt just the tiniest roughness at dead center. I was very surprised to find the bearings were totally trashed at dead center and about 1/2” either way. I’m not as aggressive a rider as you, but still surprised at the damage I found. I remember when the bike was new to me I had to get used to the amount of input required to turn. Maybe the bad bearings contributed to that.
I couldn't say as mine was so bad from the day I got it I never rode it. I've ridden a number of Ducatis from the 1990s that all steered with a heavy feel so I don't know that had anything to do with the steering head bearings. Even the Diavel which I rode at a factory demo day back in 2013 had the same heavy steering trait.

My steering head bearings were really bad in the same center area. Just like yours, mine were trashed. The rollers were not all that bad, but the outer race they rolled against had divots you could not only feel but see with no magnification at all.....sean
 

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I had several rollers in the rear center that bore no resemblance of roundness, and rust. Pitting and chewed up races at the center point. The damage was very localized along the center, but then you can’t turn them very far so I’d expect that.
 

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Discussion Starter · #19 ·

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Discussion Starter · #20 ·
Thanks for all the input guys. It’ll be a while before I can get to it but thanks to all the above comments, I have plenty of things to check. The cause will hopefully be revealed - and duly repaired.
 
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