Tire size issues

[ghostwriter78]

In my country there is a lack of 190/55 rear tires but 190/50 are available. What will the effect be on IMU/electronic or any other potential issues if I use 190/50 tires?

Import of tires is problematic: 35% tax and potential to be confiscated

[JonTheChron]

You will loose some handling, as for the other features, I would look into the effects of tire dimention change on other bikes that have the Bosch 6-axis IMU (Ninja 1000, Z1000SX, ZX-10R/RR, H2, ect)

[kman0066]

It would be a smaller diameter (by a slight amount) in just the rear. So this should not affect the IMUs directly, it's the wheel speed sensors that will measure differently than the original programming. I know those are used for speed measuring and ABS, not sure if the data get's used elsewhere. They have some tolerance built in (because of changing tire conditions/wear), but not sure of this particular bike and the amount of the effect.

It's certainly not ideal to go with the smaller profile for handling purposes. If I had to guess, you shouldn't notice any difference in day to day driving. If you really push the ABS, you may find it activating ABS a bit sooner than before. The speedometer also may read off, up to 2 mph off at 60mph.

[Switch18]

Smaller profile will result in less side wall to use... worst case scenario you could ride of the edge of the tire. A 50 profile will give you more high speed stability

[cOoTeR]

The smaller diameter tire will spin more rotations for a given speed than the larger one. So the wheel speed sensors COULD possibly read that the rear tire is slipping and activate the traction control since the rear is spinning more than the rear.

[Rickifumi]

On my Tuono Factory 1100 there is a CALIBRATE mode which Aprilia recommend you perform after changing tires or gearing. It's performed in 2nd gear, twenty-something mph +/- a fraction, for ten seconds on level ground. The ECU will update its parameters accordingly.

Do these bikes have a similar capability?

[Champ87]

On my Tuono Factory 1100 there is a CALIBRATE mode which Aprilia recommend you perform after changing tires or gearing. It's performed in 2nd gear, twenty-something mph +/- a fraction, for ten seconds on level ground. The ECU will update its parameters accordingly.

Do these bikes have a similar capability?

No calibration on the H2 SX. Calibration is needed for bikes that take speed from the output shaft - e. g. your Tuono, my Sprint. For the H2 SX speed is taken from the rear wheel speed sensor so is unaffected by gearing changes. Of course, a change in tire profile can throw readings out but it seems going from a 55 to 50 ratio tire is not something Kawasaki felt the need to allow for.

[Rickifumi]

The Aprilias use rear wheel rpms to input the speedometer. The cal function feeds front and rear wheel speeds into aPRC for more accurate T/C and wheelie control programs.

[steadly2004]

So unfortunately, I went to get new tires. I went to a dealership near me and ask them for OEM tires, but they didn't have any and they said that the ones they carry are cheaper and better performing. The try to sell me on some Michelin pilot 2ct, but I didn't want those because of the softer side wall and I have them on my supermoto. I'm aware they performed very well, but I feel like they have to soft of a sidewall for this heavy motorcycle. Ended up paying them $600 to put Michelin road 5 installed, and on the way home I noticed my traction control was triggering. I have my settings on medium power and 3 for traction control. it only kicked in on low speeds, under 15 miles per hour and over 15% throttle. as soon as I got home and called to complain about it, the technician insisted that it's because they are new and slick. He said they're actually slipping. He insisted that I drive them 50 miles and bring them back if it continues to do it. I have just finished about 60 miles, the tires are not slipping at all as far as I can tell. But, the same condition exists where low-speed and medium throttle triggers the traction control. I've called and left them a message that I want the correct size tire, hopefully they will replace it without a further charge. Especially since I was under the impression that I was getting OEM "size" tires.


On another note, I really hate that this is my first post. But, it's still pretty cool motorcycle.

[Burmashave]

Welcome to the forums.

I don't know about other guys, but the mental image I always have when running new tires is the slipperiness you get when you walk with new leather dress shoes on carpet. I don't expect traction until they're scuffed in, after about 100 miles. My local dealer (now closed) was always great about reminding me to take it easy for the first 100 miles whenever I had tires done.

You can check out some of the tire threads. Most guys are ditching the OEM Bridgestones for either the Michelin PR 5's or the Pirelli Angel GT's (now GT 2's).

viewtopic.php?f=19&t=646
viewtopic.php?f=2&t=580
viewtopic.php?f=8&t=1183

Are your tires OEM size (120/70 ZR 17 front, 190/55 ZR 17 rear)? If so, mebbe starting a new thread might have worked better.