School me about rear sprockets

Hiya.
Josh from Sydney here.
The Pani S (if it ever freakin' gets here) will be my first Ducati. (currently riding a 2010 Busa)
I have ridden a few Ducatis and the all seem very tall geared. Especially in 1st obviously. Seems from what I have seen on Youtube the Pani is the same.
Strangely though, I don't read much from people trying to shorten the gearing just slightly via a different rear sprocket.

So... school me o' wise ones..

j.

-1 in the front = faster take offs. -1 in front and +1 or 2 in the rear = insane.

2012DUCATI1199 said:

-1 in the front = faster take offs. -1 in front and +1 or 2 in the rear = insane.

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Thanks 2012,
I've read -1 on the front can be bad for shafts and chains due to the sightly reduced diameter and tighter turn for the chain. Hence my thoughts to change the rear only.
I'm not really looking for a lot more poke, just to dial out a touch of the long-leggedness / clutch slipping from standing starts and in traffic.

j.

No problem. good luck.

joshinthecity said:

Thanks 2012,
I've read -1 on the front can be bad for shafts and chains due to the sightly reduced diameter and tighter turn for the chain. Hence my thoughts to change the rear only.
I'm not really looking for a lot more poke, just to dial out a touch of the long-leggedness / clutch slipping from standing starts and in traffic.

j.

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I agree with not changing the front sprocket, go +1 or +2 in the rear

zaster said:

I agree with not changing the front sprocket, go +1 or +2 in the rear

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Thanks Zaster,
Do you also agree that going +1 on the rear would get me the result I'm looking for?
Or am I on the wrong track altogether ?

j.

joshinthecity said:

Thanks 2012,
I've read -1 on the front can be bad for shafts and chains due to the sightly reduced diameter and tighter turn for the chain. Hence my thoughts to change the rear only.
I'm not really looking for a lot more poke, just to dial out a touch of the long-leggedness / clutch slipping from standing starts and in traffic.

j.

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From what I understand you are not going to have the clutch slipping problem with the 1199.
But I do know what you mean as I did have problems with the 996r, but it is not so bad now I changed the sprocket and but a better slave cylinder in to make the clutch lighter......something Ducati should have done ages ago to make clutches lighter.

joshinthecity said:

Thanks 2012,
I've read -1 on the front can be bad for shafts and chains due to the sightly reduced diameter and tighter turn for the chain. Hence my thoughts to change the rear only.
I'm not really looking for a lot more poke, just to dial out a touch of the long-leggedness / clutch slipping from standing starts and in traffic.

j.

Click to expand...

Not so much bad for the chain because of the reduced radius... but suboptimal because the smaller the cog the less contact points on the chain. Get to a certain size and the load shared by few cogs may be too great and you may end up breaking teeth. An unlikely event... a more likely event is increased wear on the cog, which means shorter intervals between replacement.

joshinthecity said:

Thanks Zaster,
Do you also agree that going +1 on the rear would get me the result I'm looking for?
Or am I on the wrong track altogether ?

j.

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No, I would do +1 or +2 to improve the low end performance. Since I don't have the bike in front of me I can't comment on possible clearance issues with pipes etc.

+2 could also effect your chain lenght or wheelbase. You would have to check before just installing...

One day, when my 1199 gets here I'll start with front -1 and take it from there. My R1 is running -2, +1, for track use...and it makes an old bike feel very exiting to ride

Hi,

IMHO, I would avoid changing sprockets untill you've had atleast a few weeks or months to run it in and get used to the different power delivery of a Ducati as opposed to a Japanese bike. In general Manufacturers have a pretty good idea as to what gearing their bikes need in order to benefit best from a given engines power curve. So changing sprockets is mostly usefull only if you have a very specific use for your bike ie: a particular track, drag racing, or raising top speed.

Second, I would avoid, if possible, changing the front sprocket. Whereas changing them makes a much bigger impact, the same efect can be achieved by increasing or decreasing more teeth on the rear sprocket. Particularly when reducing the size of the front sprocket, as already mentioned above, the radius maybecome too small for the chain to travel properly, one of the guys in our DOC recently bent his drive shaft that way.

You also have to remember that changing a sprocket always comes at a trade off. If you drop a tooth in the back to increase top speed, you also decrease acceleration. Similarly if you go up one to increase acceleration, then you sacrifice a little top speed.

Here some articles that will help if you want to try it anyway.
AMA Pro Road Racing News - Tech Tuesday: Motorcycle Final Drive Ratio

Understanding Gearing - Workshop - Visordown

Renthal - We Build Championships

Delta One said:

If you drop a tooth in the back to increase accelleration, you also drop the top speed a few KM. Similarly if you go up one to increase top speed, then you sacrifice a little acceleration.

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you have this backwards.

mangler7 said:

you have this backwards.

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You're right, fixed it now. LOL, hopefully he read the links not my drivel

Delta One said:

You're right, fixed it now. LOL, hopefully he read the links not my drivel

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just go to www.gearingcommander.com

the 1199 isnt in the database yet but it will give you exact numbers for top speed and rpm changes due to sprocket changes.......been using this forever now

d1098man said:

just go to Gearing Commander: Motorcycle Speed, RPM, Chain & Sprockets Calculator

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!! thanks for posting that

I just did 650 miles in 3 days, going to go for a 520 -1 +2 when a speedo healer comes out. Not satisfied with the stock gears.

TransNone13 said:

I just did 650 miles in 3 days, going to go for a 520 -1 +2 when a speedo healer comes out. Not satisfied with the stock gears.

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That's gonna be a BEAST on the bottom end !

I did that with every bike I've ever had -1/+2. The biggest being my CBR1000RR. I have a RC8R Track, I haven't looked at the gearing; but it certainly has enough torque down low whereas the 1199 is amazing high, but I'd rather have more grunt than top speed. 170 is plenty for street AND track use.

BTW My "home" is Weston despite living in Colorado Springs.