So it's time for a new chain and sprockets (15k on them), and I was planning on doing the 14t front when I got to this point. But after doing a little searching I have seen people advising to go up a tooth or two in the back rather than down one in the front in the name of chain longevity. Since I am planning to do the whole set, I might as well get the best option rather than just the front sprocket for cheap and easy.
So...because I am kinda partial to MonstarParts and I am placing an order with them anyway, I was looking at the EK MVXZ Series X-Ring Chain (520 is fine from what I've read), and the AFAM front and rear sprockets. I just don't know what tooth counts to go with. Mostly because I don't know what the stock tooth count is on the rear.
Advice?
According to Ducati.com your sprockets are 15/39. That's quite heavy and an obvious candidate for mods.
"Everyone" were crying out for changes to the 15/41 found on for example the S2R800, so to recommend quite big changes on the 796 is safe.
I think 14/41 is great for this bike, but 14/39 will also be a nice improvement.
The chain longevity theory sounds sensible, but I'm not convinced that it matters much... If you insist on a 15 front, you'll need a 44 rear to get where "everyone" is happy on their S2R and the like. If so, you'll need a longer chain. Study this to find out exactly how much longer http://www.gearingcommander.com/ (http://www.gearingcommander.com/)
The chain I was looking at doesn't specify length...
Maybe split the difference and go with 14/40? I thought I saw something about keeping tooth numbers even/even or odd/odd. All I can think is that it would affect how the chain wears to the teeth, though I really don't see how it would matter much with steel sprockets..
Quote from: freeclimbmtb on February 22, 2016, 09:44:22 AM
The chain I was looking at doesn't specify length...
Maybe split the difference and go with 14/40? I thought I saw something about keeping tooth numbers even/even or odd/odd. All I can think is that it would affect how the chain wears to the teeth, though I really don't see how it would matter much with steel sprockets..
I ran 15/43 on my S2R1000 and was quite happy with it.
I'd stay 15 and go 41 rear maybe 42... My M620 had 15/48 went 14/48, nice yes, highway riding, NOT so great, I might go back to 15/48 or 15/50 . ..
The idea is NOT to stress the transmission to shaft itself, some over time, get an oil leak due to the shaft being "forced" on the housing.
Quote from: freeclimbmtb on February 22, 2016, 08:54:00 AM
~~~SNIP~~~
Advice?
What kind of riding do you do?
Urban? Highway commuting? Weekend fun riding?
Is it flat where you ride, or hilly?
Quote from: Speeddog on February 22, 2016, 11:11:52 AM
What kind of riding do you do?
Urban? Highway commuting? Weekend fun riding?
Is it flat where you ride, or hilly?
Right now, pretty rural roads, with 8 miles of highway to and from work. Occasional stop and go when I am in town.
I may be relocating to San Diego CA though, so it really varies..
I'd go 15/41. The torque numbers are very similar to the early M900, and 15/41 works great on my bike. Comfortable (low vibes) in 6th on the highway, and plenty of oomph in the lower gears.
+1 on the 15/41
Sounds good to me.
14 front is a good way to go when the bike is new enough to change just th sprocket and save a bunch of money. Will a smaller sprocket increase chain wear? In theory, yes. In reality, only one small variable, certainly not nearly as important as chain maintenance.
As far as the even odd thing goes, what you are looking for is a number that does not divide evenly, in other words, if you were just talking about two gears and no chain for simplicity, if the small gear has 10 teeth and the large gear has 30 teeth, you would have a 3:1 ratio and each tooth of the pinion gear will come in contact with the same teeth on the ring gear each revolution. This is called non hunting and most prone to wear and can be noisy upon reassembly if not marked.
Change the big gear to 35 teeth and you now have partial non hunting, and any one tooth of the pinion gear will come in contact with some of the teeth on the ring gear each revolution. This set up should also be marked to avoid noise.
Most preferred is a hunting gearset where any given tooth on the pinion gear contacts all of the
teeth on the ring gear before it meets the same tooth again.
I can't believe I typed all that because the chain makes all this pretty insignificant, particularly if you avoid a sprocket set that does not divide into a whole number.
Summary, if you want to gear down, go with the 15/41
Quote from: howie on February 22, 2016, 04:30:37 PM
14 front is a good way to go when the bike is new enough to change just th sprocket and save a bunch of money. Will a smaller sprocket increase chain wear? In theory, yes. In reality, only one small variable, certainly not nearly as important as chain maintenance.
As far as the even odd thing goes, what you are looking for is a number that does not divide evenly, in other words, if you were just talking about two gears and no chain for simplicity, if the small gear has 10 teeth and the large gear has 30 teeth, you would have a 3:1 ratio and each tooth of the pinion gear will come in contact with the same teeth on the ring gear each revolution. This is called non hunting and most prone to wear and can be noisy upon reassembly if not marked.
Change the big gear to 35 teeth and you now have partial non hunting, and any one tooth of the pinion gear will come in contact with some of the teeth on the ring gear each revolution. This set up should also be marked to avoid noise.
Most preferred is a hunting gearset where any given tooth on the pinion gear contacts all of the
teeth on the ring gear before it meets the same tooth again.
I can't believe I typed all that because the chain makes all this pretty insignificant, particularly if you avoid a sprocket set that does not divide into a whole number.
Summary, if you want to gear down, go with the 15/41
No, I'm glad you did type it all out because it answered my question perfectly. Engineers don't like pushing the "I believe" button...we like to know the why.
Sprockets and chain ordered yesterday, I have a buddy with the chain riveting tool. Just need DucatiOmaha to answer my email about the DU737 and that will basically finalize my build for good.