Rear sprocket REQUIRES chain adjustment if going up several teeth - front sprocket the change in diameter is small enough its not really an issue....

All in all, it just seems like a lightweight 14T FS is just a ton cheaper to do, @ ~$50, you're done!

 

I went up 3 teeth in the back. No complaints but I did do a new chain at the same time.

 

Why would people want to change the rear when it apparently costs more in parts and time? Also (am I the only one that gets this?) going up teeth in the rear and putting on a bigger chain only adds weight. Going to a 14t loses a tooth in weight. Isnt the point to drop as much weight as possible. Also, why do people keep questioning not doing a 14t when apparently its never given anyone any problems. Boggles my mind.

 

A 14t front will limit the amount of ride height/swingarm angle you can get. I always go up in the rear & leave a 15t up front.

 

always do the front first. because -1 tooth = +2.5 at the rear.
then if you want more, add some in the back.

on my S4 i had -1F +2R and it was great since i used the bike every day rain or shine, as a commuter and canyon carver. since the bike had no wind protection, 240 Kmh top speed was more than enough (read: useless). so i was happy to be able to use less clutch in the city.

now, after 8000 Km on my S4rs with only the front at -1 i plan to go +1 at the rear as well during winter mods for next summer. [thumbsup]

 

oh, Norm has a point... especially since the Monster's stock suspension setup is s.h.i.t. and needs to be raised at the rear.

with that logic, a 14t front with a 44t at the rear would be fine but not as recommendable with stock 43t rear.

 

Why would people want to change the rear when it apparently costs more in parts and time? Also (am I the only one that gets this?) going up teeth in the rear and putting on a bigger chain only adds weight. Going to a 14t loses a tooth in weight. Isnt the point to drop as much weight as possible. Also, why do people keep questioning not doing a 14t when apparently its never given anyone any problems. Boggles my mind.

Norm gave the main reasons to change the rear instead of the front but another reason is that the smaller the sprocket the harder it is on the chain beniding it into a tighter circle. If you do a search you will find many people that have had the chain eat their swingarm with the 14 tooth sprocket. Sorry to boggle your mind....

 

Norm gave the main reasons to change the rear instead of the front but another reason is that the smaller the sprocket the harder it is on the chain beniding it into a tighter circle. If you do a search you will find many people that have had the chain eat their swingarm with the 14 tooth sprocket. Sorry to boggle your mind....

Norm unboggled my mind and I accept that. However, Ive never read one issue on this forum about a 14t sprocket.

 

The idea of staying with a 15t front makes some sense to me - swinging arm geometry. Having said that, I ran a 14/42 for 12K mi. on my ex s4r and a 14/44 as well. I’ve bave been running a 14/43 on my current bike for 3500 mi. and haven't seen any evidence of swinging arm interference etc. with one inch increase from oem ride height. I measure one inch clearance to the swinging arm in front of my current 43t rear and I have been thinking of going to a 44t rear.

If you tried to replicate the 3.07 ratio of the 14/43 you would need a 15/46 (3.066) and I'm not so sure that would fit. The 14/44 ratio is 3.14 and it just kicks ass.

All this makes me want to rethink the final drive ratios Ducati picked for the gear box of these bikes.

I like being able to run in 6th gear at something approaching legal speeds. A 14/43 does that and if you're over 3500 rpm, you never have to shift.

I live on the Blue Ridge Escarpment where straights are fairly short and a tall gear ratios are not really the "hot setup".

I concur with Waldorf's -1 on the front is +2.5 on the rear.

And Norm, should we be doing something more constructive at 8:30 on Sat. night? Maybe not.

LA

 

Norm unboggled my mind and I accept that. However, Ive never read one issue on this forum about a 14t sprocket.

It may have changed with the newer generation of ST series based frames but several years ago it was a pretty common topic on this board. I remember a thread or two that showed pictures of the swingarm damage but it only happend when the ride height was raised in the back. .

 

There are a number of advantages to running a 15t with a larger rear sprocket, as opposed to a 14t with the same rear sprocket:

The chain links move a smaller angle wrapping around a 15t, so chain wear is reduced.
Rate of wear on the front sprocket is reduced, as there's more teeth.
Wear on the chain is reduced, as the driving tension is less.

It is slightly heavier, but that's a common compromise to get longer life on any part.

As far as the cost, if you're replacing the whole set, it doesn't much matter.

 

Here is why I like a 15t, if I could fit a 16t into the space allowed, I'd run that. The angle of the bottom dotted line in the sketch below controls the amount of squat or anti squat that a bike displays under acceleration. As you can see, when you steepen the swingarm angle, you provide more anti squat which allows you to get on the gas earlier & harder when exiting a corner without running wide. By reducing the size of the front sprocket, you limit the amount of angle you can achieve on the swingarm.

 

Norm,
when you're right... you're right.

now another question. previous Monsters are equipped with 15t and 41/42 to suit their gearing. these can be replaced by a 44 or 45.

my S4RS has 15t and 43t sprockets from the factory. since i plan on raising the rear suspention considerably, i would be best to stick with a 15t up front but where the hell could i get a 47t for the rear? i have never seen that anywhere.

typically, a 916/996 aftermarket sprocket will 39t to 41t for track use.

any thoughts?

 

Making the front sprocket smaller or the rear larger, will both have an anti squat effect. If you have enough chain/swingarm clearence, go with the smaller front, but most Ducati swingarms are pretty limited in that area. trying to put a 47t on a SSS would be quite a trick.

 

You're preaching to the choir about using the big front sprocket to achieve proper geometry. I'm 100% with ya on the 15 or even 16 tooth front sprocket, but we're left hanging. Like I said, around here I don't need 170 MPH gearing, but what are the choices up to a point? Because of the gearing Ducati choose for the transmission we can't fit the sprockets needed to get to the 3.07 or 3.14/1 ratios I'd like to use without using a 14t front. Ducati obviously saw the problem or they wouldn't have fitted an easily replaceable rubbing block or swing arm protector or whatever I should call it.

My Bro-in-law rides a 950 KTM SM. It comes with a 17 tooth front sprocket. All the room you need.

I got 12,500 Mi. on the chain of my old s4r with no damage to anything that I could discern, and it still had life left in it. I'll just keep and eye out for interference/wear on the rubber swing arm rubbing block and go back to the 15 it I have to.

LA

 

What bike do you ride Rendler? Any engine mods?

 

[...] Ducati obviously saw the problem or they wouldn't have fitted an easily replaceable rubbing block or swing arm protector or whatever I should call it [...]

Has anyone actually wore out or replace this swingarm protector?
If yes, what was your setup (e.g. 14/41) and how many miles? I just noticed today that there is a slight smudge on the swingarm which looks like it was caused by chain touch it.

 

I've worn thru a few of them but I can't remember any particular settings. I *think* the 748 bikes came with 14t sprockets.