Time for a new chain and sprockets for my 749s. Faster acceleration is preferable to top speed. I like the idea of going up 3t on the rear as opposed to down 1 on the front. I am after a standard quality chain, but don't know If I have to order a specific length, of If I just order a chain and then cut the excess off to suit my purposes. Would appreciate some advice for where/what to buy.
I think the 749 came with a 14 tooth front sprocket so I dont think you can go down on the front . 3 up on the back is good but if I were you I would go maybe 5 or even 6 up as you need a longer chain anyway . You can always come down and remove a link but you cant really ad them if your still not happy . I have a 41 tooth rear sprocket , up from 36 , on my 999R and its still good for 155+ , autobahn , mph .Still have the standard 15 tooth sprocket on the front. This is a good app for you to try your choices first. Gearing Commander: Motorcycle Speed, RPM, Chain & Sprockets Calculator
14/39 on the 749 as standard (14/38 on the S). I went down one on the front (from Talon IIRC). Been running that for a few years now. Also worth adding a throttle tube from a 2004 R1 (part no.#4YR-26240-01-00), less than £20 from a Yamaha dealer, a very cheap quick action throttle.
I've got the R1 mod on my 999 and 1198 (the part number I used though was [FONT=&]4YR262400200)[/FONT]. Apparently 2c0-26240-00-00 from a R6 is even quicker but needs some mods with a dremel. It was cheaper to mail order than go to my nearest Yam dealer Motorcycle Spares, Scooter Spares, Motorcycle Parts, Scooter Parts, Motorcycle Helmets & Motorcycle Clothing
BaggaZee & Chris I already have a quick action throttle fitted, definitely the best mod' to make imo!
In that case, gearing copmmander will tell you what you need regarding chain length, wear rates for sprocket combinations etc. On the old site a lot of people talked about the dangers of dropping a tooth at the front but as I said, I did it a few years ago, have done plenty of trackdays since and had no problems.
I thought my 749s had a 15/36 as standard :/ I didn't alter the front but sent up to a 38 on rear, seems good but could easily go up to the 40's for more bottom end grunt
I think I need to do some counting of teeth tomorrow as I'm not sure what sprockets are on there atm. Thanks for the help.
So from Ducati up North the standard setup on a 749s is 14f-39r, and the recommended is 14f-43r with the consequence of a 8mm shorter wheelbase.
14f38r according to the manual, but it wouldn't be the first time it's been wrong! Edited to remove typo 17f!
John, on my 749 I dropped the front to 13 and put 3 on the back to 42. Occasionally hit the rev limiter in top, shows about 153 on the speedo.
Phil Now you have me all confused as I know you know what you are talking about. Here is an extract from the Ducati up North site: Tales of the Front Sprocket One of the easiest performance changes that a new owner can make is to lower the final drive gear ratio by changing the sprockets. The stock gearing is selected to enable Ducati to reduce exhaust emmisions, but is simply too high for most road use. Ducati bike models have a wide range of torque output and the size of the chain and Ducati’s selection of sprockets reflect this range of outputs. The 748 and 749 series (with the exception of the 749R) all have torque outputs below 80Nm so they are supplied with 14-tooth front sprockets and 520 chains. Starting with the higher torque 916-series (and 749R), and continuing with the 996, 998 and 999, the factory shifts to a 15-tooth front sprocket and a 525 chain. Why? Because more torque means more chain tension and a 15-tooth front sprocket lowers the tension in the chain by seven percent. A 525 chain has a tensile strength that’s ten percent higher. So you get an overall 17 percent stronger setup. Still-higher torque SP, SPS, R and Corsa models output over 100Nm so how do they get away with 14-tooth sprckets and light-weight 520 chains? That’s easy. Once you get over a certain torque level (for a given weight bike) the bike will wheelie before the chain tension exceeds it’s strength limits. At least for awhile, chains on these bikes don’t usually see 15,000 miles of service. So, what does this tell us about changing our final drive components. Four things. First, as a general rule, it’s better to increase the rear sprocket size to avoid the higher chain tension resulting from a smaller front sprocket. Changing from a 14-tooth front to a 13-tooth front, for example, increases chain tension even more (9 percent) than a shift from a shift from a 15 to a 14-tooth. Second, the heavier the bike, the higher the chain tension needed to make it wheelie and the higher the maximum chain tension it will experience. So, a 680 pound 916-plus-rider will generate a higher chain tension than (say) a lightweight Corsa-plus-jockey or even a Suzuki GS-X. When a chain under tension elongates 10 percent, it needs replacement. Frequently for a Corsa bike. Three, combining a change to a smaller front sprocket with a change from a 525 to a 520 chain on a higher-torque model Ducati will significantly weaken the final drive load capacity. Reports of chain failures are common enough, so it may not be wise to ignore this point for the sake of saving 275 grams of chain weight. Four, there’s a practical limit on the size of the front sprocket. You end up carrying higher loads with fewer teeth. No manufacturer puts a sprocket smaller than 14-teeth on a bike with a torque output of a Ducati. I think that the above suggestions to put a 13-tooth sprocket on a 749S (because it’s cheaper) are ill-advised. A better solution is to change to a 41-tooth rear sprocket. This will require a new 96-link chain. Since I am starting with a blank canvas, in that I definitely need to buy a new chain and sprockets, and that I believe I can't go up to 15t on the front;as I have a 'chaincase saver' fitted, and there isn't enough clearance for that. It seems to me that my best option all round to achieve better acceleration without putting more load on the chain is to retain a 14t front and to use a 41t or 43t on the rear.
Make sure you get a chain for which there is a spring link...... I have a DID 520ZVM (not a 520ZVM X)....can I get a spring link? Nope...........and I now have to be careful which rivet link I get as well, because even though the 520ZVM X is a minor upgrade for the 520ZVM, the rivet links aren't the same. Plus, I'm not even sure which bl**dy riveter will do the job......... It's even got me looking at the possibility of making a removeable section of the swing arm brace.... AL
Al I'm getting so frustrated with looking for a chain and sprocket replacement , can't seem to find any supplier for my requirements despite looking for about 3 hours this morning on internet, I'm presently considering buying an easily obtainable, relatively cheap standard replacement chain and sprockets. Never done this before and I'm surprised I'm having these problems. Please enlighten me why you want a spring link, am I missing something here?
here's a good 'rule of thumb' site that is useful if only as a guideline :- Ducati 749 S (Monoposto/Biposto) 04-06 Parts at Wemoto - The UK's No.1 On-Line Motorcycle Parts Retailer
Chris My first port of call normally. However they don't do what I'm after - a 43t rear sprocket! Any idea where to get what I'm after?
