Ducati Monster Forum

Hi All,

I'm going to change out my chain and sprockets on my '04 S4R.  I can't find a 43T sprocket (525 pitch) for the life of me.  I don't want the "quick change" stuff, just a standard steel 43T sprocket that bolts up the way the OEM 42T does.

I already have the stock/new 15T front, so no worries there.  Any help is greatly appreciated!

Option #1

https://www.solomotoparts.com/Supersprox-Stealth-Black-525-Rear-Sprocket-for-996-Monster-S4R-04-06/

(https://images.solomotoparts.com/images/D/RST733black-09.jpg)

Option #2

Err, never mind. I was going to suggest this ...

https://japan.webike.net/products/22760557.html

... but I have no FHE with this brand.
(Supersprox stealth, yes.)


JT used to make one piece rear sprocket (in both steel and aluminum) but they are discontinued.
(And they aren't high quality sprocket anyway.)

Is there any reason you are specific about this gearing?

15:42  to 15:43  you are lowering only 2% ...

Woo, that ain't a cheap date, but it is what I was looking for.

I guess the reason I'm looking for that gearing is because I currently have a 14T up front and a 42T in the back.  I'm going up to a 15T up front (since I have the original with ~600 miles on it), so I figured going up to a 43T in the back would be similar to what I have now.

Ok, hold on...upon further investigation, it looks like I'd need to go to a 45T to keep the same 3.0 ratio, correct?  I guess I'm looking for a 45T now if that's the case.

I may be remembering this wrong, but when considering tooth counts, you don't want the front and rear to be exact multiples.

In your case you'd want 15/46, or 15/44, but not 15/45.

Hmm, ok. 

I guess I have more research to do. 

Thanks so far, guys!

More discussion... http://www.ducatimonsterforum.org/index.php?topic=44458.0

What you have now is (in theory) not ideal. You have even number tooth on both sprockets, and the ratio is exactly 3:1.

If you like the way your bike behaves (gearing wise) now, and are planning to replace both sprocket and chain at the same time, I’d say, 15/44 (2.93 : 1).

15/42 is stock.  I believe the S4RS is 15/43 stock.

Derek V

All good stuff here.  I'm learning a lot today.

I guess I'm shooting for a 44T now (yes, I do like the way the bike behaves), so a hunting I will go...

Thanks!

I never really understood the same tooth same link argument.  I am running 14/42 on the S4RT.  I had 14/43 and needed a new rear. My mechanic could only get a 42 in a pinch.  I asked about the both being even gearing and he said it shouldn't be much of a problem.

For simplicity I will use a ring and pinion set up like a differential in a car.  

Nonhunting gearset:

Each tooth of the pinion gear will come in contact with the same teeth on the ring
gear each revolution.
The gears must be assembled with the index marks aligned or a gear wine will result and possibly shorter life.  An example ratio is 4.0:1


Partial nonhunting gearset:

Any one tooth of the pinion gear will come in contact with some of the teeth on the ring gear each revolution
The gears must be assembled with the index marks aligned.  An example ratio is 4.5:1.


Hunting gearset:

Any given tooth on the pinion gear contacts all of the teeth on the ring gear before it meets the same tooth again.  The gearset does not have to be indexed
An example ratio is 4.73:1


In theory a hunting will give you longer life.  Sprocket and chain on a bike?  IMO maintenance is the key to long life.  Again, opinion, but I think, since you are dealing with a sprocket, chain and sprocket unless your ratios come out to a prime fraction (4:1) you are good.  Non hunting would require marking components when doing work like removing the rear wheel to avoid noise. Theoretically not a good idea to replace only one component.  Then again, if there is mileage on the components they should be changed as a set anyway.  Low mileage on the set and you want a different ratio I would do it.

Also, I am a big fan of Afam super Lights.  Usually about the same weight as Supersprox.

Thanks Heath and howie.  I always due proper maintenance so that definitely helps the lifespan.  I think the main issue now is finding a setup that works.

https://sprocketcenter.com/street-sprocket-applications/ducati/996-monster-s4r-2004-2006/superlite-50608r-rs7-series-black-525-pitch-steel-rear-quick-change-sprocket.html

I found those, yeah.  I also found the Superlights.  I don't really want to go the quick change route, so I'll probably go with the OEM style.  I may just go with the chainwheel/chain kit that Superlight has on their website and be done with everything.

Ok, I did some research on hunting tooth and found this calculator: https://www.blocklayer.com/chain-sprocket.aspx

According to this, I'd be good with a 15T front and a 45T rear (gets me the same ratio I have now, which I like).  Now, the optimal wear rate is at 100% as long as I don't go over 107 links on the chain.  Stock is 104 links  I'm not exactly sure how many links I would need to add if I went to this setup, though...

Thoughts?

Don't trust a site, or the results given within, which lists 107 links as an option. (links are sold in pairs)

Check Gearingcommander for exact numbers (even though they also, occasionally, talk about strange link numbers)

From 42 to 45 is larger, but only on one half of the sprocket. 1.5 tooth longer. Plus the 0.5 change from 14 to 15. Two links longer chain (tell me if I'm wrong)

OK, thanks.  I knew links come in pairs (forgot to mention that), but was just noting the calculator.

Rechecking Gearingcommander...

.... damn, now I don't trust my own numbers. Checking too.  :-\



EDIT: no, I'm good  [thumbsup]

IMO
For most riders
If you snuck in their garage one night and changed their bike up/down one tooth on the back
They'd never notice
Typical freeway cruise, one tooth is a 100 rpm difference
1 needle width on the tach

I agree, but also have another spin on how this can feel..... add one more tooth, up four now, and you're VERY close to the total difference between fifth and sixth / having 'lost' sixth all together  ;D

Don't use those calculators.
Don't try to order the chain cut "exactly what I'd need" length.
I wrote this many years ago

http://www.ducatimonsterforum.org/index.php?topic=71572.msg1321563#msg1321563
(Although all photos are gone, Youtube videos are still there.)

https://youtu.be/gFEO2PtTA0E

Just buy full length chain, and put it over a set of new sprockets.
No need to calculate anything, and most importantly, you won't get "too short" chain this way.

So, stop messing around with calculators and stop wondering how many links you'd need.

Thanks, all!  I think I'm good to go now.  I appreciate everyone's help.  Good to be back on the board after a 7 year hiatus.