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Discussion Starter #1
hen I took my S4 in to Ducati Austin for its 600 mile service, I hade them make 2 changes, adding to the extreme gearing change I already had them make:

1. Replaced stock flywheel (4.2 lb) with Nichols flywheel (9oz)

2. Raised rear ride height 10mm

I would have liked to isolate the changes, but given my current job status which requires being out of town EVERY week except for weekends, I figured I'd have them do both so I have next weekend free to just ride.

Here the results so far, after about 50 miles:

Nichols flywheel:

After the parts counter man rode the bike from the shop to the front parking lot, he remarked "MUCH more responsive to throttle".

I had not told my wife about the change, and was curious to see if she detected any audible difference. She did. She says it sounds "more metallic".

The idle is a bit more fragile sounding, and I noticed that the mechanic had set it to 1000 to 1050 instead of the 900 or so it was idling at before.

Vibration level at idle, or at any rpm I've been to so far, is unchanged, maybe even a bit smoother (the Nichols flywheel might be a bit better balanced than the stock one, and certianly any unbalance is going to have less effect on the super light Nichols than on the heavy stock flywheel. The difference in weight (I weighed my old flywheel on a Postage scale) was 3lb 9 oz. I revved to about 8000 (I have just over 800 miles on the odometer now) maximum. I crusied at up to 5000 RPM (with my extreme gearing, that's only about 70 mph).

The gear shift quality is unchanged (it was great before the chnage and continues).

The engine DOES feel revvier. It has more of the feel of a "multicylinder" now. Throttle blipping is much snappier now.

The engine sound seems unchanged to me, but note my wife's "blind test" comment above.

Overall: I cut over 3.5 lb off my bike, with no apparent negatives, and got a slightly racier feel to the engine. I'm happy.


Raising rear ride height:

This also felt good to me! I was warned that it can make a big difference in feel and to be careful, but it felt just wonderful. The bike seems even more nimble than before. I might ask them to raise it even more and see what happens.


Gearing change

When I took delivery, it was with 14/42 gearing, rather than the stock 15/37, a change of almost 22%.

Because I am still breaking the bike in, I don't yet know what happens at very high rpm. Until recently, I have been limiting myself to 6500 or so, and have just started raising the limit a bit at a time as I get more miles on. So, this is pretty preliminary.

I LOVE the way the bike feels with this gearing under "normal" conditions. There is NOWHERE where you find yourself with insufficient power or rpm. Highway passing requires no downshifting. Getting from 4000 to 6500 in top gear is RAPID.

The FEEL of the bike is one of TAUTNESS and responsiveness.

1st gear IS a continuous wheelie once you hit the throttle. If I PLAN the throttle application (like from a stoplight), and lean forward a bit, it's helps keep it lower. Even when on one wheel, the bike tracks absolutely true. Of course, do NOT try this on anything less than a STRAIGHT, FLAT, and DRY road!!I'll let you all know more as I get enough miles on to go to peak revs iin 1st, 2nd , and 3rd.

Jim G
 
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14/42 holy sh1t dude. I have an S4, and I went down one in the front and love it. I thought of going up on the rear, but I am concerned with overall loss of top speed.

You have to let me know how second gear wheelies are. Can you get it up from a straight roll-on?

What is your max speed in top gear at around 7k RPMs?
 

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Discussion Starter #3
DucGasm: I have no idea what the ACTUAL top speed will be for 2 reasons:

1. I'm still breaking in the bike
2. I am not interested in going that fast!!

However, my computer model says the top speed will be unaffected by the gearing change, since the stock gearing is WAY off the ideal for top speed.

The model says the bike will hit 140 mph, limited by the limiter. In the case of my S4, which has the correct "Corsa" chip to match the Termignoni hi-pipes and open airbox, the chip sets the limiter at 10,000.

Note that a higher limit of close to 11,000 can be obtained via another chip which assumes the presence of the Corsa cams. If a limit of 10,500 can be applied via a sutiable chip, the top speed with this gearing would be at 143, so no huge loss.

And as I stated above, I have no interest, even after breakin, of finding out. About 120 is my personal limit, and even that only when I am SURE "there is no one in the forest to see the tree fall", or on a track.

You asked what speed I am doing at 7000 rpm. That is about 98 mph with my gearing. Why do you ask about that particular rpm?

As for 2nd gear wheelies, I have not tried! The first gear ones are unintentional, and to me, undesirable, since steering with the front wheel in the air is a bit of a trick. I like control.

I plan to try to reduce the tendency to wheelie by changing my TOTAL bike weight distribution (bike & rider) with a number of possible approaches:

1. Adjustable rearsets (believe it or not, they can be used to move your weight in EITHER direction, depending on your NET posture with pegs and bars)

2. Adjustable clip-ons

Jim G
 
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My fear of loosing top speed isn't actually for top speed. I don't want a really high RPM at cruising speeds.

It is not uncommon to run down the interstate at ~100mph when going to ride somwhere. I don't particularly enjoy the high speed stuff, but I don't want to tac the bike up just to keep up. And I don't want to run 7k rpms for a 30 min period.
 

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Discussion Starter #5
Yes, I see that you and I ride differently.

I don't like 100 mph on an unfaired bike - not very comfortable - and there's nowhere in our area where I would be willing to take the chance of doing it regularly anyway because I value my clean license and my low insurance!

My fastest "prolonged" cruising speed seems to be about 75 mph, which translates to 5400 rpm, which is just fine on an engine that is mechanically capable of 11,000 (with the right chip - no strucutural improvements required).

Since my bike is NOT used for "getting to places" but rather as a way for me to have fun on windy and steep and therefore slow backroads, the higher rpm is just never an issue. I bet that if I calculated out my "average" speed somehow via a datalog of some sort, it'd probably be pretty slow, as a typical 2 hour ride puts only 100 miles or less on the bike (that is literally a 50mph aveage speed!).

I find freeways boring. I like to feel like I'm flying about 5 feet above the road on a windy and hilly road . . .

Jim G
 
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You are a lucky man. Unfortunately, I had to move into the city for school, so I must "commute" to a decent twisty road.
 

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Jim,

Taking the rear up really improved the ride of my bike also. It doesn't feel light in the front anymore when exiting curves. I have about 6 threads showing now at either end of the tie rod. This is about as high as you can go w/o tearing up your top chain wear plate with stock gearing. With your gearing, you might find you have a bit more adustability. I did some experimenting with raising the rear and if you go too far, the swing arm angle gets too extreme. I have seen a reference on this board to the S4R manual saying that the max is 5 threads top and bottom. With going up two in the rear, I should have more clearance for the chain to swingarm angle break. When I get more clearance, I will be taking it up even more.
 
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Hi MonstaS4

I had the rear of my 02 S4 raised 15mm, and from memory that is about 5 threds each end.

The change has been excellent, the bike turns in and does right/left flip flops more easily so mission accomplished. The change was done at the same time as adding a 14t front sprocket, really complementing the suspension mod.

Could you tell me a bit more about the swing arm angle you refer to and tearing up the top chain slider.

The shop seems to have left more chain slack than standard, is this poor service or done for a reason related to the s/arm and sprocket changes?

Also, does the rear suspension lift affect the clearance from pipe riser to swingarm (I have high rise Sils on)? My right riser pipe rubbed the swing arm during my fist serious ride after the change, but the shop had to remove the exhaust to change the rear head (warranty/battery leak job), and now I don't know if it's been reassembled poorly or if I have a true clearance issue.

Any help appreciated, as you may notice from my ramblings I am happy, but just a little woried/confused.



Jim,

Taking the rear up really improved the ride of my bike also.
 

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Discussion Starter #9
S40Z: Becareful in HOW you measure the chain slack. I made this error myself recently, and had to apologize to the shop mchanic.

After my 600 mile service, I checked the chain slack and it was slack enough to lift the chain link at midpoint between the countershaft and the rear axle fully up to the swingarm without it ever getting tight! I called my shop and asked if the mechanic had forgotten to tighten it during the service.

He responded that he had indeed cleaned, lubed, and adjusted it, and would I please re-check it by having someone sitting on the seat while I check the slack. It was precisely the amount of slack specified in the manual!

I realize the owners manual doesn't tell you to check it with a rider on the bike, but it does make sense to do so, as that is how it will be in actual use! I think on most bikes, the measurmeent might not be wildly different done either way (with or wothout the rider on the seat), but with my VERY modified 14/42 gearing (stock on an S4 is 15/37), it makes sense that the geometry will have changed!

The mechanic pointed out that if he had adjusted it to the apparent required slack with no rider aboard, it would have been tight enough with a rider aboard that it would have seriously hurt both the chain and the wheel and gearbox bearings.

I humbly apologized.

Jim G
 
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Thanks for the eye opener on chain tension, Jim.

Anyone has got some experiences Re high rise exhaust and swing arm clearance with riser pipe, after having raised the rear suspension?

Stefan
 

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Discussion Starter #11
S40Z: Along with the greatly altered gearing, my 02 S4 has both the high Termi pipes and increased rear ride height (10mm higher than stock).

No interference issues.

The 10mm increase in height improved the handling.

Jim G
 

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It might just be the way your Sils fit. I don't know from experience but some people on this board have had issues with high pipes specifically the "s" bend pipe up to the can. Try moving/loosening the header to slip on clamp and try moving the pipe out a bit. It might be the reinstall from the shop or the pipe itself, the swingarm angle is independent of the pipe fit.

I was addicted to the way the bike handled so much better with the rear end up in the air. I took it up too far and the rear end got light through corners and I destroyed my chain wear plate. See how 7 or 8 threads effects the angle of your swingarm next time you are adjusting the tie rod. Don't ride it just so you have the visual of the interference I am referring to. If my chain would have been really tight, I would have toasted a lot more.
 
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Thanks for the advice Re the pipe - now I know I have some fiddling times in front of me.

Re. "Don't ride it just so you have the visual of the interference I am referring to." - What do you mean?

Is rasing height by 15mm likely to cause the chain plate tensioner you and others refer to?

Stefan

It might just be the way your Sils fit.
 

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If you really want to get the chain tension exact, try this:

Support the bike by the bottom of the engine, or by the frame with straps to the rafters of your garage, or whatever skyhook you have.

Detach the shock linkage.

Compress the rear suspension until the axle, swingarm pivot and C/S are all in a straight line. That's the maximum chain tension position. Adjust the axle position until there's just a bit of slack in the chain.

Reassemble.

Support the bike however you want to normally do when you check chain tension; track stand, on the sidestand, or whatever.
Check the amount of slack in that condition, and thereafter use that as your ideal setup.

Even with this method, if you adjust your pushrod, the slack in your 'normal' position will be different, because the geometry is different.

If you normally check it with the rear suspension unloaded, IE bike suppported under the engine or 'skyhooked', preload changes will not effect the chain slack. If you check it with the rear wheel or swingarm supporting some weight, preload will change the amount of slack.

HTH.
 

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S40Z: Along with the greatly altered gearing, my 02 S4 has both the high Termi pipes and increased rear ride height (10mm higher than stock).

No interference issues.

The 10mm increase in height improved the handling.

Jim G
Another way is to pull the forks up through the triple clamps thus lowering the front, this in my opinion has more effect than lifting the rear,i had both done on my S4 and have done exactly the same on the S4R,---back up 10mm,front down 8mm,--don`t go any more than 8mm though as there are clearance issues above the 8mm--and be carefull for a couple of corners-it really does alter the speed/rate of turn!!!!!
 
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Another way is to pull the forks up through the triple clamps thus lowering the front, this in my opinion has more effect than lifting the rear,i had both done on my S4 and have done exactly the same on the S4R,---back up 10mm,front down 8mm,--don`t go any more than 8mm though as there are clearance issues above the 8mm--and be carefull for a couple of corners-it really does alter the speed/rate of turn!!!!!
i think you're correct about dropping the front on the forks has a more dramatic effect, but be wary of how far you go. it's been reported that front wheel clearance to the horizontal cylinder head gets really risky for contact under heavy braking/bumps.
 
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Wll finally got a 300Km ride in yesterday, on known roads with tons of corners.

Havig raised the rear by about 15mm and fitted the 14t front sprocket I was keen to experience the effects.

Well, accelleration is fantastic, the Ducati's quality of being able to hold one gear from corner to corner, using the engine's torque and rev range is enhanced by the gearing change. Low speed, traffic & suburb work is also easier and less jerky.

Rips out of corners, great fun!

Handling has also been enhanced, easier to drop into a corner, hold on line and exit without running wide. Flip flops in tightish corners is also greatly improved.

Confidence inspiring.

Two great, inexpensive improvements.

A happy bunny (no Easter pun intended ;-))

Stefan
 
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