Different tires. T/C settings.

The DTC system on the 899 (and the 1199, 1199S and 1199R for that matter) is hard-coded and pre-programmed for the Pirelli OEM tires and Pirelli SC2 race tires only. The system has no capability to be "programmed" for different tires. The only bikes Ducati makes that have the ability to be set up for different tires are the 1199RS factory race bike, and the upcoming 1199SL. Now that being said, it does not mean the system won't "work" with different tires, it totally depends on what level of precision you need for the type of riding you're doing. The farther you get away from the size (mainly the rolling circumference) of the OEM tires, both front and rear, the less precise the system's intervention will be. As mentioned above, you can certainly play around with the different levels and see what works with the tires you're running, and if you find an acceptable compromise that's great. But keep in mind that the system is designed for wheelspin prevention at lean, not upright, so testing the system when upright is pretty much pointless. Go on your normal ride, get the throttle twisted coming out of the turns like you normally would, and if you're getting good grip with no tire spinning, and no or very little appearance of the yellow light on the dash, then you should be good to go at that setting. If you ever perceive a tire spin in the rear, and the light doesn't flash, then you need to turn the level up to get it responding sooner. If every time you twist the throttle on corner exits you get the yellow light coming on, then you need to turn the level down so it's less intrusive. As long as you stick with a 180 profile rear and 120 profile front for street tires, you should be in the ballpark and likely the system will work well enough by finding the right level. For the track, it's a different story, and you need to try to find race tires that are as close as possible to the stock profiles, since the precision of the system is more critical for track use. I found with certain tires on my 1199, I had to completely turn DTC off on the track because even on Level 1 it was too intrusive. Once I found some tires that were closer in circumference to the Pirellis I was able to start using it again on Level 1 and it worked pretty well. Hopefully at some point, Ducati will release an updated software capability to program the system for new tired circumferences, but that's probably a year or two away since that capability is just not going to be coming out on the 1199SL and likely won't "trickle down" for a little while.

As delivered, the DTC system is set up with the levels to be used as follows:
Level 1 - Pirelli SC2 (or other) RACE tires on the track
Level 2 - OEM Pirelli tires on the track
Level 3-6 - OEM Pirelli tires on the street, higher lever means more sensitive response for less aggressive riding
Level 7-8 - OEM Pirelli tires on the street in very slick conditions (Rain, cold, sand/gravel, etc.)

jarelj said:

The DTC system on the 899 (and the 1199, 1199S and 1199R for that matter) is hard-coded and pre-programmed for the Pirelli OEM tires and Pirelli SC2 race tires only. The system has no capability to be "programmed" for different tires. The only bikes Ducati makes that have the ability to be set up for different tires are the 1199RS factory race bike, and the upcoming 1199SL. Now that being said, it does not mean the system won't "work" with different tires, it totally depends on what level of precision you need for the type of riding you're doing. The farther you get away from the size (mainly the rolling circumference) of the OEM tires, both front and rear, the less precise the system's intervention will be. As mentioned above, you can certainly play around with the different levels and see what works with the tires you're running, and if you find an acceptable compromise that's great. But keep in mind that the system is designed for wheelspin prevention at lean, not upright, so testing the system when upright is pretty much pointless. Go on your normal ride, get the throttle twisted coming out of the turns like you normally would, and if you're getting good grip with no tire spinning, and no or very little appearance of the yellow light on the dash, then you should be good to go at that setting. If you ever perceive a tire spin in the rear, and the light doesn't flash, then you need to turn the level up to get it responding sooner. If every time you twist the throttle on corner exits you get the yellow light coming on, then you need to turn the level down so it's less intrusive. As long as you stick with a 180 profile rear and 120 profile front for street tires, you should be in the ballpark and likely the system will work well enough by finding the right level. For the track, it's a different story, and you need to try to find race tires that are as close as possible to the stock profiles, since the precision of the system is more critical for track use. I found with certain tires on my 1199, I had to completely turn DTC off on the track because even on Level 1 it was too intrusive. Once I found some tires that were closer in circumference to the Pirellis I was able to start using it again on Level 1 and it worked pretty well. Hopefully at some point, Ducati will release an updated software capability to program the system for new tired circumferences, but that's probably a year or two away since that capability is just not going to be coming out on the 1199SL and likely won't "trickle down" for a little while.

As delivered, the DTC system is set up with the levels to be used as follows:
Level 1 - Pirelli SC2 (or other) RACE tires on the track
Level 2 - OEM Pirelli tires on the track
Level 3-6 - OEM Pirelli tires on the street, higher lever means more sensitive response for less aggressive riding
Level 7-8 - OEM Pirelli tires on the street in very slick conditions (Rain, cold, sand/gravel, etc.)

Click to expand...

Fantastic response, very ingesting and informative. Over the years, getting on
A bit now!, I've had many a quandary re tyres and grip on many a different bike, especially running on the track where temps generally run higher than the road use we experience the most.

I agree most bike manufacturers favour a particular make/model of tyre and advise use of that tyre, however, over the years I've found in addition to this, rider style and preference can play b big part in this too, especially with rider confidence, Especially on the track, where individual rider style can play a big influence on the way a bike can handle, especially with rider confidence. Personally, I favour Pirelli or Michelin tyres, I've ridden, and ditched bikes on certain tyres, which has given me little faith in them since, although I wouldn't write them off in the future, but I do have my favourites I'd be more confident on. Each to their own, and their own riding style, everyone rides their bike as their confident with the handling and response, and long may that remain.
By the way, think the bar has run dry!!

mcouper99 said:

I have no idea how the DTC magic works, and the following questions may well put that on full display. That said, can someone explain why tire size and profile have an impact? I would think that wheel spin is just that, a sudden increase in rotational speed not caused by 'normal' inputs. Slippage seems like something that could be measured by a change in torsional force. Both of those seem measurable regardless of tire size. What am I missing?

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Good question! There are two main types of TC, "inertial" and "differential". Intertial TC is what systems like the Bazzaz do, which is exactly as you described: They measure the rate of increase in rear wheel speed or engine RPM to detect abnormal rate of increase indicating a rear-wheel spin-up. Differential TC systems use front and rear wheel speed sensors (and often other sensors) to detect increases in the speed of the rear wheel in excess of the speed of the front wheel. All professional racing TC systems are differential, it's WAY more precise and able to detect other types of slip conditions such as a sideways sliding slow spin-up that cannot be caught by an inertial system. Not all differential TC systems are equal, the ones that use additional sensors to detect lean angle for example are even more precise. The DTC system is differential, with both front and rear wheels speed sensors plus a sensor mounted in the tail. It's a very precise system trickled down directly from Ducati's World Superbike systems. The only real limitation is the software/programming, so for example on the World Superbike Ducati, you'd find much more complex programming set up with very specific slip-maps for each tire compound, each track, and even different temperature settings for a particular track. All of the racing teams have an electronics technician whose job it is to continually refine this programming throughout the race weekend. Obviously we don't have that in our production bikes, they are programmed with a baseline slip map and allow the rider to adjust the response with the levels, but we can't adjust the actual tire mapping or change any other parameters of the response. Some of the aftermarket systems, such as the Nemesis TCS system which we've used on many race/track bikes over the years, or more programmable since they're aimed mainly at racing rather than multi-purpose application.

Yes that's true, if you put a smaller profile rear tire on and matched it with a proportionally smaller front tire then the speed differential would be similar to what the system is expecting and the system should work similar to how it does for the stock tires in recognizing the differential. However, with a 120/70 front there is very little difference in rolling circumference for different tires vs. the huge differences in rolling circumference in rear tires that are available, ranging from 180/55 to 180/60 (the stock size) in various brands. So if you put on a smaller circumference rear tire the odds of finding a proportionally smaller front tire are very slim. However the TC system also is programmed with what is knows as a "slip map" which measures the amount of rear wheel slip that is expected and needed to generate a certain amount of forward thrust. Different tire designs, rubber compounds, etc. have a varied amount of slip that is required to generate thrust. This concept is a little harder to wrap the mind around, but basically if you had zero wheelspin when accelerating at full throttle you would not be getting as much forward thrust (g-force) as you would if you had a little bit if wheelspin. So the slip map is programmed with the desired amount of slip to be allowed for a particular tire. An example would be when we were developing the Bridgestone tire maps for the Nemesis TCS system, the difference in slip when accelerating between the R10 DOT race tire and the V01 Slick race tire was huge. Because of the carcass design and rubber compound differences, the R10 required much less slip to generate forward thrust than the Slick did. So if we had the R10 slip map loaded in the system but had the Slick tires mounted up, the system was virtually unusable because the amount of slip (wheelspin) generated by the slick was much higher than the R10 map was expecting, so the TC would cut in very harshly and kill the drive coming off the turns because it thought there was too much spin. That is the reason that the professional systems are fully programmable, because there's a lot more to it than simply the size of the tire. But tire size is still the MOST important parameter, so the closer you can be to the stock size the better the system will work. And with the ability to adjust the system across the 8 levels, most people should be able to find an acceptable setting for different tires for street riding or non-racing track riding. It's only at the higher levels of racing or fast track riding that it becomes something more critical. Ideally the DTC system would allow simple programming to plug in (or use the wheel speed sensors to detect) the tire circumferences and adjust the slip map accordingly. However the system today does not allow that function other than as I mentioned earlier, on the 1199RS factory race bike and the 1199 Superleggera. Hopefully that functionality will be coming down the pipe sometime soon for the rest of the bikes.

So are we to believe that any 180/60 profile rear will work with the DTC but switching to a 180/55 will produce unreliable intervention by the electronics?
How does the Aprilia system work on the RSV4? That bike apparently adjusts for a range of sizes. Is it just a matter of time until Ducati 'catch up'?
The other question is why did Ducati opt for the less conventional 60 profile rear fitment. Cynics say it's just Italians looking after Italians. Who knows?
Interestingly Dunlop have entered the fray by introducing a 180/60 Sportsmart. Does that suggest the profile is going to become the norm? Currently the only other bike that takes this size is the 848 Ducati Streetfighter. That seems quite a niche market to enter.
Currently I think most 600 Supersport and Superstock 600 in the UK race with Pirelli Super Corsa's in 60 profile but the bikes don't run TC systems. Will the Japanese factories switch tire sizes for the next generation of their bikes and Dunlop were privie to this information?

Great questions!

Cerec1 said:

So are we to believe that any 180/60 profile rear will work with the DTC but switching to a 180/55 will produce unreliable intervention by the electronics?

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No, but in general a tire size that is closer to the stock size is more likely to work better, but there is no substitute for actually trying it. In general, if you put a smaller circumference rear tire on with no change in front tire size, then the system is more likely to cut in earlier due to a predisposition in the system thinking that there is wheelspin due to the rear tire turning quicker on the smaller circumference tire. But that doesn't mean the DTC system "won't work", it just means there will be a pre-disposition to an earlier intervention, so it would be reasonable to run your DTC at a lower level in that case. There's no substitute for actually trying it and adjusting the system to your preference for different tires. I would never use the word "unreliable", that insinuates that you won't know what the system is going to do, which is not the case. The system will respond exactly the same in the same situation with the same tires every time, so you can definitely rely on it. It's more a matter of whether you're willing to do the work to get your levels dialed in for your tire choice and riding conditions/style, or if you want the simple answer. If you want to be guaranteed that it will work perfectly in all situations at the default DTC levels, then your only option is to stick with the OEM tires.

Cerec1 said:

How does the Aprilia system work on the RSV4? That bike apparently adjusts for a range of sizes. Is it just a matter of time until Ducati 'catch up'?

Click to expand...

The Aprilia system does exactly what the 1199RS and 1199SL DTC systems do, which is it allows the TC parameters for front and rear tire circumference to be altered by putting the system in "learning mode" after fitting new tires so the system can measure the rolling speeds. Yes, it's just a matter of time before Ducati decides to open this up in the software as well.

Cerec1 said:

The other question is why did Ducati opt for the less conventional 60 profile rear fitment. Cynics say it's just Italians looking after Italians. Who knows?
Interestingly Dunlop have entered the fray by introducing a 180/60 Sportsmart. Does that suggest the profile is going to become the norm? Currently the only other bike that takes this size is the 848 Ducati Streetfighter. That seems quite a niche market to enter.
Currently I think most 600 Supersport and Superstock 600 in the UK race with Pirelli Super Corsa's in 60 profile but the bikes don't run TC systems. Will the Japanese factories switch tire sizes for the next generation of their bikes and Dunlop were privie to this information?

Click to expand...

Overall there has been a trend in rear tires to taller and taller profiles, as carcass designs have changed and technology has continued to develop allowing that to happen. Overall the advantage to a taller profile is a flatter crown radius which gives a larger contact patch at full lean, as was as an easier transition from upright to lean. Pirelli has been moving that direction with the spec tires in World Superbike the past couple years as the regulations changed from 16.5" wheels to more street-oriented 17" wheels. That technology is trickling down the street tires, in much the same way that Bridgestone's MotoGP tire technologies trickle down. Our shop is the Bridgestone race tire distributor for the Midwest and we've been watching this happen. For example, the rear profiles on the Bridestone slicks have grown much taller over the last 5 years, to the point where the 190 rear Bridestone slick is virtually the same height as a 200 profile Pirelli OEM tire on an 1199 Panigale. This is all a good trend as it produces better tire performance, but it does result in the market being fractured between the manufactures who have adopted the newer tall profiles and those who are still catching up. Regarding the 899, I really don't think the switch to 180/60 profile was done for any reason other than it's the best tire choice to provide the best handling with that chassis. Unfortunately for those of us who are going to run different tires, it makes our job more difficult to get the electronics dialed in for the other tires. So I don't think the choice of 180/60 was done to protect or favor Pirelli in any way, but I DO suspect (personal conjecture only, no facts) that the lack of programming functionality in DTC for other tires has at least a nod toward encouraging owners to stick with the OEM Pirelli tires, another Italian company...