Was out in the thunderstorms last night, flicked bike into trc 3 and full power mode, intentionally, to see how good this thing works, what actually suprised me most was how much grip the tires bridgestone s20 have in the wet, was not so easy to get the traction indicator moving on the info screen , overall im impressed, it takes a little geting used to, as when it kicks in my first reaction was to give it more throttle, but nothing happens, its weird not to hear and see revs climb where you know you should be getting wheel spin, its very smooth and almost undectable , sometimes the bar moves, but you dont notice and movement from the bike, that said im not sure how far the indicator moves in relation to the amount of wheelspin you are getting, but so far, i like it

Not directly related to this but to the traction control:

Does it make any difference in KTRC functionality point of view if the rear tyre is different profile as original one e.g. 190/55?

* Last updated by: Vmatti on 8/23/2012 @ 9:59 AM *

i can not see why it might effect it

The TC works by ,initially, comparing F&R rotational wheel speeds. A higher profile tyre will have a bigger circumference so will be turning slightly slower by around 3%. The system on my 1198sp was effected by non-OE tyre profiles. The system on the 14 is undoubtably better but could still be affected. Why you would want to but a higher profile tyre on anyway is beyond me.

* Last updated by: pegscraper on 8/23/2012 @ 3:28 PM *

hmm, yes i suppose you are right, how did you come to 3% ? just curious, wheel speed sensor is closer to center of wheel than outer circumference of tire, but yes i suppose any difference in wheel speed should be picked up, but is there a parameter % of difference that is build into design?, leaned right over would the different width tire on front vrs back not give a slightly diff wheel speed?

I have a couple points of data, one is direct and the 2nd is anecdotal.

I can say for certain that the software and firmware developers count on a specific set of tire parameters, including all the physical aspects of each (F + R) tire. Name a tire parameter, and it will be in a coded lookup table. The state machine running executing on the microcontroller/ processor is fetching each variable parameter many time per second, depending on environmental conditions (tempreature/ air pressure/ lean angle/ and yes wheel speed differentials, etc). Fixed parameters are typically fetched once per bootup, like wheel size (tho, I'm not sure about thinks like sidewall height. They're relatively fixed, but with tire flex during rotation, and lean angle, they may make it a variable).

The processor fetches from the looup table depending on all these parameters, and sorts out the branch decision logic, in code, based on the moment by moment conditions. All this factors into the TC experience you get on the cycle.

Bottomline: The point is, change any of those parameters, and you'll change the behavior of the TC.

Anectotally, last month Ducati was invited to a superbike shootout in Motorcyclist magazine (to provide their new Panagalli <sp>). The magazine staff required that each cycle in the shootout be fitted with the exact same tires.

Ducati refused to fit anything but their spec'ed tires, and they sited as the reason this very thing, that the TC parameters would be changed to be something other than what they designed for, in code.

Software becomes important...

Good ?? Vmatti.. My 10 comes with 55 series rear and it's great for quick turning, anything lower seems slow..
Only downfall is cost... I'm gonna ask my mechanic to call kawi tech and see what they say...

Thanks for good feedback and facts on this issue as it seems to be nowadays quite common as "many" of bikes have TC.
Friend of mine who's riding BMW S1000RR actually said me that "do not change profile" and he was told by some BMW guru.
That's why I raised this here.

My conclusion was:
My new tyre is still 190/50 as original ones, actually 3rd set after 9500km ;)
"Power has the price"

@ pegscraper: reason to change is that possible "quick turning" - even with 50 profile it's good enough.

* Last updated by: Vmatti on 8/25/2012 @ 11:08 AM *