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Discussion Starter #1
I've been trying to decide whether to change my rear or front sprocket. I like the idea of a newer, lighter rear sprocket, but froont sprockets are cheaper and easier to put on. Has anyone had issues with a front sprocket causing damage to your chain, etc??? I've heard that it causes more stress on the chain(which seems logical) because it bends further, and faster than with a stock front. I want more RW torque on my 600, and am thinking of either going 2-3 up on the rear, or 1 down on the front... am I in the right ball park??? TIA...
:)
 
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I put the front sprocket on and love it. Easy mod, no new chain, and lot's of tourqe. The chain issue is up in the air, I only have 400 miles on mine and have seen no problem's. Most people recommend the front and rear swap, but the front only has worked for me. Careful pulling the clutch slave, it can make a huge mess if you do it wrong.
 
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Yeah. During the install, you'll have to remove the 3 allen bolts that hold your clutch slave cylinder. You might be able to do the job with the slave on, but it's less hassle if you just remove it.
Don't worry about the slave cylinder. Just remember NOT to pull the clutch lever while you have it off. Other than that, you should be fine.
 

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Maybe our bikes are different, but I didn't have to mess with the slave. For me it was just remove cover, remove sprocket, lightly grease shaft, install new, locktite screws, reinstall cover, and adjust chain. Took 20 minutes at most.
 

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This issue has been brought up before and nobody was able to produce solid evidence that a 14-tooth sprocket causes any additional wear to the chain or anything else.

I've also installed a 14-tooth front sprocket in 20 minutes without touching any clutch parts. Don't remove the slave unless you really have to.
 

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SlickRick: I have a custom computer program I wrote for engineering gearing changes.

I didn't do a simulation on a 600, but I did do one on the 620, and it said that the hot ticket for the 620 was a 21% overall increase in final gear ratio.

That means a 14T to replace the 15T, PLUS a 54T versus the stock 620's 48T.

That combination would give the following results:

0 to 60 mph: -0.47 sec (HUGE impact)
0 to 80 mph: -0.49 sec
0 to 100 mph: -0.56 sec
1/4 mile: -0.37 sec
Maximum G's acceleration: from 0.85G to 1.04G

Horsepower available at 60mph without downshiffting: up from 28hp to 37 hp (+32%).

However, this would raise your rpm at 60mph from 4487 to 5430, which means no long 80 or 90mph runs!

A compromise would be to go 14T in front PLUS 49 or 50T in back. That would keep your rpm at 60 around 5000, which is ideal for a motor that size and configuration (high rpm motor). This combo would still give you a 14% increase in hp available in top gear at 60mph, a big reduction in 0 to 60mph time (0.24 sec) and a smaller reduction in the other times.

Don't worry about 14T on the front causing stress. Not a problem unless you want to TOUR and put on LOTS of miles, in which case you will wear the chain faster.

Jim G
 

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When I put the 14 on I had to loosen the slave bolts but not actually remove it. I just needed a little wiggle room.
If you keep your chain tension right you wont have a problem with wear. If its too tight it will wear out the plastic chain guide and start in on the swingarm.
 

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Discussion Starter #9
I'm known to ride for 7+ hours at a time, and am planning on a 14 hour trip soon... I also commute 1.5 hours daily... My "happy" speed is (80-100mph) and I rarely go 120, normally keep under 110, so If I maxed it to 105-110, I'd be happy with a little more low end power...
 

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SlickRick: Do you have a 600 or a 620?

Model year?

Is it 5 speed or 6 speed?

Jim G
 

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AFAIK, all 750 and smaller Monsters have 5-Speeds, and 800 and larger have the 6-Speeds.

SlickRick may have recently changed his Sig Line to show his bike...'01 M600. BTW, SlickRick, you've seen 120 indicated on your 600? That's pretty fast for a 600.
 
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A few days ago, I installed the 14T front sprocket on my '03 M620 (using an AFAM/52604-14). I'm not really concerned about any ill effect on the chain from past experience. NOTE: The 620 has a really large rear sprocket (to begin with) just to get you rolling along.

One thing that I've noticed after this mod: @ 80mph / 6k RPM

What are your thoughts on all day runs at 6k RPMs? any concerns? or no...

Richter
 

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Discussion Starter #14
I normally travel around 5.2K-5.6KRPMs and the highest I've had it (not accellerating) is around 6.5 (I believe, I'll have to pay attention next time). Going 120 is usually when I'm traveling with the wind, and feels about 85 would with no wind. The highway I ride tends to go west to east/east/west, and wind tends to travel parallel in the same directions... (unfortunately, it's usually in the opposite direction of travel). :(

Also, for any police out there, this is theoretical, I'd never really exceed the posted limit. ;)
 

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Russoduc: Your speedometer is very optimistic!

Stock gearing on a 620ie is 15/48, which yields 4487 rpm at 60mph STOCK, which is 6000 rpm at 80 mph STOCK.

If you changed from 15T to 14T, you actually need to hit 6410 rpm to be doing an ACTUAL 80 mph. At you indicated 6000 rpm, you are doing an actual 75 mph.

Slick rick: I don't have the gear ratios and dyno curve for the 600 (as opposed to the 620), but I know the 600 has less horsepower virtually everywhere than the 620 does (the 620 was a BIG positive change for Ducati), and so you want gearing that gives you about 4800 to 4900 rpm at 60 mph.

If you send me via email, or post here, your indicated rpm at 60 mph with your current gearing, I can tell you what you need to do to get there.

If you go further and get some information for me from your owner's manual, I MIGHT be able to find a dyno curve for the 600 somewhere, and run it through my program. The info I need from you to do this includes:

- Primary reduction ratio (likely around 1.85)
- Number of teeth on countershaft sprocket (likely 15)
- NUmber of teeth on rear sprocket (around 48?)
- Individual gear ratios for gears 1 through 5 (will range from about 2.5 for 1st to about 0.9 for 5th, I think)

I may be able to find a dyno cruve in some old literature.

Gearing is the most cost effective and easiest performance change you can make on almost all Ducati's, as they are geared from the factory for noise and emissions compliance versus performance.

Jim G
 

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Well, for starters, you're not going to run all day at 6K. You stop for gas, you change speed for turns (unless its Interstate all the way, even then there'e traffic), you stop for food and nature. So you're likely at 6K for relatively short periods. If you're good about your oil changes and watch your oil temps shouldn't be an issue. More problems from lugging the bike than from higher rpm.

 
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Seriously, the monster loves to be revved. My 620 likes cruising at 6000rpm, and pulls hard up to 8500.

02 monster 620, leo vinci hi mounts, tpo pods/velocity stacks, pCIII.

twist it man
 

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Discussion Starter #18
ummmm.. nope, I'm at 6K for long periods... (45Min straight --> 10 Hours (Rt. 66 and 81) I stop for food once on my trip, and gas only when I'm getting low, and briefly...
My butt probably would like longer breaks, but I like to be where I'm going... yesterday.
I do need one of those fancy Rick Mayer custom seats... mmmmm.... Maybe I'd ride more than 10-14 hours at a time.
After 7, by Butt feels like It was smacked with a hard 2x4...

Hey Jolly, did you mod your sprockets? or are they standard?
 
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