KTM 790 Duke Forum banner
41 - 58 of 58 Posts

·
Registered
2020 790 Duke
Joined
·
723 Posts
Man that sucks Fred. I hate mechanical mysteries.
The known: Bike was fine before the low side but is not now. Something changed and need to find out what.

Initial assumption: Perhaps something was missed during inspection and re-assembly of the forks.

Action: Disassemble forks and re-check everything. Double checking nothing is bent and nothing was installed backwards or upside down. Take extra care during disassembly to verify all components are properly in place. Thoroughly clean and inspect everything ensuring that no small piece of crud was left in the internals.

Hopefully you will discover the culprit and you can return to just ride and enjoy mode. If not find a convenient cliff then turn it into your insurance and get new 2022 machine...just kidding. :rolleyes:

Good luck and keep us posted.
 

·
Registered
Joined
·
212 Posts
So the one thing I didn't do was take the forks apart. Once I removed the forks and wheel and loosened the triple I was able to line everything up and install without issue, so I hoped that meant nothing was bent. But in speaking with Dave Moss he thinks there's something binding such that when compression is set to firm the oil movement is restricted and makes the fork behave weirdly, and once I loosen up the compression the oil can flow enough where the fork can push past the trouble spot.

Next step will be to take the forks and triple and bring them to GP Frame & Wheels to have them measured and straightened. What a drag...
 

·
Registered
2021 KTM Duke 890R
Joined
·
716 Posts
Just replaced my S22 with a new S22. 4,056 miles. I basically wore out the center of the tire. I bought the tire Febuary 5th 2022. So 9 months of riding 1 day a week with a few commuting days to work thrown in. Other the recent low speed crash I had, I've liked these tires.
 

·
Registered
2020 790 Duke
Joined
·
303 Posts
I got just under 3000 miles from the S22s. Nice and cheap but I got over 4000 miles from Conti Sport Attack 4s and the Power 5s. Trying a set of Q3+ now. Those are noticeably taller than anything else. I did lower the clamps to the third line down.
 

·
Registered
Joined
·
212 Posts
Based on circumference and radius calculations the Pirelli front is +1mm taller and the rear is +4.5mm taller, so net chassis attitude is +3.5mm. I’m already running my forks at the 3rd line to compensate for the stiffer Andreani fork so I’m gonna leave it and see how it feels.
 

·
Registered
Joined
·
166 Posts
Once the tires are installed and inflated, the end results might be a bit different.
Dave Moss showed this in a video some time ago (although he got confused with the figures at one point, if I remember well!).
 

·
Registered
2020 790 Duke
Joined
·
303 Posts
Based on circumference and radius calculations the Pirelli front is +1mm taller and the rear is +4.5mm taller, so net chassis attitude is +3.5mm. I’m already running my forks at the 3rd line to compensate for the stiffer Andreani fork so I’m gonna leave it and see how it feels.
You could also take a bit of preload out....
 

·
Registered
Joined
·
201 Posts
s22 rear looks like its got like 75% tread life still after 2k miles

i dont think I wheelie alot, but my oem front power cup at 5k+ now still has like 30% tread left, my front end suspension geometry is quite drastic from stock as well
 

·
Registered
Joined
·
58 Posts
i got a flat on my rear early on, replaced with the diablo rosso 3 and its noticeably a peakier tire....i dont have alot of street experience but do on dirt and have really good feel with most things and i can feel a difference between the powercup rear and diablo rosso 3....bike doesnt feel the same in corners, it feels like front and rear want to do different things....i didnt change anything else on the bike......still feels ok just not the same......idk if its compound, profile, etc......

would go back to power cup 2 or get matching tires....bad move on my part, it was on sale and had decent reviews so
 

·
Registered
Joined
·
212 Posts
I’ve mixed the Power 5/GP/Cup 2 because they’re basically the same tire with different tread patterns, but I imagine the bike will feel weird if you mix brands since the profiles aren’t matched. You’ll have different contact patches and turn in behavior, probably not ideal riding conditions. Would highly recommend finding a mate to whichever tire you prefer.
 

·
Registered
Joined
·
58 Posts
will be doing that very soon...diablo compound feels harder than the michelin so ill just go to michelin again....not a commuter bike and i dont ride in rain so.....i got a flat literally less than 200 miles after i bought the bike new
 

·
Registered
Joined
·
166 Posts
I’ve mixed the Power 5/GP/Cup 2 because they’re basically the same tire with different tread patterns, but I imagine the bike will feel weird if you mix brands since the profiles aren’t matched. You’ll have different contact patches and turn in behavior, probably not ideal riding conditions. Would highly recommend finding a mate to whichever tire you prefer.
According to Michelin, Power 5 and Power GP, share the same compound (silica + black carbon) with different tread patterns.
Same thing for Power Cup 2 and Power Slick 2. However, these 2 models contain a lot more black carbon and much less silica, if any.
 

·
Registered
Joined
·
212 Posts
Yes from my short ride this week the Rosso 4 was stiffer than the Michelin and tipped in faster. I am also about to install a Nitron R3 shock to balance out my Andreani front, so I’ll wait for the new shock before tinkering with tire pressures and geometry.
 
41 - 58 of 58 Posts
Top