Article about sport tyres and DTC

[ToniS]

I read an article about sport tyres interacting wrong with DTC on the XR, but can't find it anymore. Anybody knows what Im talking about and can you send me a link

[Antares]

Originally Posted by ToniS

I read an article about sport tyres interacting wrong with DTC on the XR, but can't find it anymore. Anybody knows what Im talking about and can you send me a link

Maybe they deleted it because I've never heard or had any issues with DTC regardless of tyres lol

[ToniS]

Originally Posted by Antares

Maybe they deleted it because I've never heard or had any issues with DTC regardless of tyres lol

Well it was an very interesting post. With clearly somebody with good knowledge of bikes and tyres. Which I cannot say of most tyre reviews from users here... Not the useall BS. But actually his experience with certain tyres and explaining what/why things are happening. Also great info on calibration of the DTC and ABS.

In fact I remember that he explained, due to the shape of sport tyres (less round and more oval for more grip on the side) this counteracts with DTC, that calibrated for more round touring tyres, which sounded logical to me.

[Antares]

Originally Posted by ToniS

Well it was an very interesting post. With clearly somebody with good knowledge of bikes and tyres. Which I cannot say of most tyre reviews from users here... Not the useall BS. But actually his experience with certain tyres and explaining what/why things are happening. Also great info on calibration of the DTC and ABS.

In fact I remember that he explained, due to the shape of sport tyres (less round and more oval for more grip on the side) this counteracts with DTC, that calibrated for more round touring tyres, which sounded logical to me.

Interesting but as far as I'm aware the DTC system is adaptive and there is even a service function to relearn the tyres, perhaps our writer here didn't use that function when moving to tyres with drastically different profiles. Besides that the DTC is an organic system that responds to what's happening right now, not just an " if more than X amount of torque at Y amount of lean, cut power" sort of system.

Only difference is Dynamic PRO assumes stickier tyres so all the interventions are dialed back but still adapt to whatever tyre you have

[ToniS]

Originally Posted by Antares

Interesting but as far as I'm aware the DTC system is adaptive and there is even a service function to relearn the tyres, perhaps our writer here didn't use that function when moving to tyres with drastically different profiles. Besides that the DTC is an organic system that responds to what's happening right now, not just an " if more than X amount of torque at Y amount of lean, cut power" sort of system.

True, but it measures the difference in speed between front and rear tyre to determine how much slip there is. So.... if the radius diminishes more than normal touring tyres, which is the case with sporttyres due to their shape, DTC will interact to soon, thinking the rear is losing traction and slipping. But he all explains that in a blog. I'm just trying to find that website. Its not a single post.

[Antares]

Originally Posted by ToniS

True, but it measures the difference in speed between front and rear tyre to determine how much slip there is. So.... if the radius diminishes more than normal touring tyres, which is the case with sporttyres due to their shape, DTC will interact to soon, thinking the rear is losing traction and slipping. But he all explains that in a blog. I'm just trying to find that website. Its not a single post.

That's what I'm talking about the DTC learning, relative tyre speeds as the bike leans over at various angles and speeds. The circumference is likely a stored as a ratio of circumference against lean angle. And when the speed steps a certain % outside of that ratio, whichever way os when TC intervenes. I can see this being an issue on some of the simpler japanese TC systems but the DTC on the BMW is one of the best developed ones out there even today.

[ToniS]

Can you please explain about the learning or recalibrating. I've never heard of that. Thank you. I had it on my Multistrada, you calibrate new tyres of new gearing. I didn't see such a mode on the XR, or is it done by the dealer/service engineer?

[Antares]

Originally Posted by ToniS

Can you please explain about the learning or recalibrating. I've never heard of that. Thank you. I had it on my Multistrada, you calibrate new tyres of new gearing. I didn't see such a mode on the XR, or is it done by the dealer/service engineer?

It's under the adaptations option where you reset the DTC, which resets the learned tyre circumference values. Should be able to do it with both motoscan and gs911 diagnostics tools

[bazzer]

This would have been the case with older simpler traction control systems. More modern systems are a bit more sophisticated.

For instance the XR has an IMU (inertial management unit) so it knows when the bike leans or is yawing (sliding) so it can use this along with wheel speed sensors and to act a bit more clever than just simple wheel speed sensors.

[Antares]

Originally Posted by bazzer

This would have been the case with older simpler traction control systems. More modern systems are a bit more sophisticated.

For instance the XR has an IMU (inertial management unit) so it knows when the bike leans or is yawing (sliding) so it can use this along with wheel speed sensors and to act a bit more clever than just simple wheel speed sensors.

This too, forgot to mention it but tyres are probably only a small part of the equation for the DTC