I appreciate this is for the 748/9*6/8 bikes but it should still hold true: Effect on wheelbase 9XX With a 96-link chain, a 15/39 combo will give you a longer wheelbase than a 15/40 (which BTW is stock length) by about 4mm (the 4 o’clock position), and also lower your rear ride height. You can recover the rear height by increasing the length of the ride height adjuster rod. Gearing Options - Ducati Up North
I had considered that, however if I was changing chain and sprockets I'd be rotating the hub back to it's original position when new or I'd run out of adjustment real quick. Are people really changing chain and sprockets without doing this very fundamental adjustment? Or are we saying that the different rear sprocket diameter is altering the required amount of adjustment significantly enough that we'd ultimately run out of adjustment much sooner? Over the natural life of the chain and with continued adjustment then it's a dynamic adjustment, much like lengthening the wheel base gradually with DSSA bikes. Either I'm missing something or people are simply experiencing the difference all in one go due to the reset to the original position, rather than it being gradually changed over the life of the chain in which case it should be expected.
-1 front will result in either the rear sprocket hub being further back or a 1 link less chain. Adding +2/+3 on the rear will either mean moving the rear wheel closer to the front of the bike or a longer chain. You can use http://www.gearingcommander.com/ to tell you how much you need to move the rear wheel in/out depending on the sprocket teeth front and rear and also the effect of changing the chain length. You can also use http://www.gearingcommander.com/ to work out how often a particular tooth will hit the same chain length which effects wear and therefore life. From everything i've read I'd always go +2 /+3 on the back rather than -1 on the front but most bikes will need a longer chain so most people save money by just -1 the front.
what he ^^^ said, it moves from being closer too 5 o'clock to 6 o'clock. Conversely, longer chain moves closer to 5 o'clock and lowers the back. FYI the 110 link is half a link too long (kinda) so it does lower the bike a fraction. Perfect for me
There is no ride height adjusted on the multi, like there is on 1098 etc, so you cannot reset the height when adjusting the chain and/or changing the gearing. Only length of chain and (a bit) preload can do that.
Theres an interesting point on a thread 'chain rubbing swinagrm' about potentially using the 14t front as that sharpens the angle and may be causing the issue on 1299?? No idea if out is, but could be.
Changing the gearing is often a good way to get round some of the limitations 'baked in' to many bikes for testing. Noise testing is usually measured at a certain rev range (4.5-5K) which can often results in a hole in the power, designed to keep the noise down. A larger rear or smaller front will increase acceleration, but lower overall top speed. On my Aprilia Tuono this is was an essential modification, the bike picked up faster, better round town and nobody misses 10MPH at the top end.
