Belt tension: Am I pushing my luck?

[JonS2R]

Allen key method would be better, since it yields loose, but not too loose. It doesn't make sense why it's different between the two cylinders.

I believe the idea is that, at temperature, the cylinders expand at different rates due to the differences in airflow they see.

[JonS2R]

There is also a marked difference in tension when newly adjusted, and after some considerable running time. It would seem to me, it is not an exact science ....       

Yeah that certainly seems to be the case. It's too bad Ducati hasn't figured out a way to use auto tensioners similar to what you see on cars with timing belts but I guess the Italians don't like to do things the easy way 

[Buhgaboo]

🤔I would guess...if it's like the m821...with the engine pulley on it's timing mark, one intake cam is under tension whereas the other is not...this means one is much tighter than the other

[greenmonster]

Did OP recheck Snyders manual about HZ 1mm recommendation?

[JonS2R]

Did OP recheck Snyders manual about HZ 1mm recommendation?

Yes. I just changed the belts yesterday actually. He does recommend a 1mm feeler gauge for the horizontal cylinder but only for the 1000DS. I just used a 1.5mm allen key to achieve a snug fit. 2mm still fits but with force. For vertical I used a 4mm allen key.

[greenmonster]

Ok, thx.

So, IS there something special about 100DS belts?

[ducpainter]

Ok, thx.

So, IS there something special about 100DS belts?

Compared to which other bikes?

[Speeddog]

Ok, thx.

So, IS there something special about 100DS belts?

AFAIK, same construction as other round-tooth air-cooled engine belts.

Different tension spec IMO is due to different:
A) tensioner location
B) head/cylinders, allegedly running cooler
C) unknown factor internal to Ducati

[JonS2R]

After riding home from work and getting it nice and hot, I checked the tension again and it didn't really seem to change all that much.

I did notice the horizontal belt just barely walked off the edge of the cam gear...likely maybe a MM. I don't remember if the old one was like that when I took it off. Should that be any cause for concern? The pulley doesn't have any play and rotates smoothly...