Scrub Radius?

[C4Dman]

Very much looking at Riva DTM's, so I have entered the details into a wheel checker, most of which is self explanatory, and have noticed something I have never heard of before and that is "scrub radius"? I have attached the screenshot that states 13 mm positive scrub if fitting DTM wheels and understand that this may affect the tyre or handling of the car?
I have attached a screenshot showing OEM front wheel, stated as RIM 1 compared to RIVA DTM stated as RIM 2, I think the figures entered for 18" fronts is correct, please feel free to correct me.
i am now nervous changing from 108's to DTM's and wonder if a straight swap of MV2's is safer and will not change anything, thoughts?

[brillomaster]

You'll be fine. Plenty of people fit spacers or slightly more aggressive wheel fitments with no problems at all.

the front tyre is already 225mm wide, so the outer edges are already scrubbing by 110mm from the centre, assuming that the point of rotation is in the middle of the tyre anyways - it probably isnt! - its part of the reason why modern cars need power steering, whereas older, lighter cars with skinny tyres can probably get away without it.

or put it this way, it would take a very very very finely tuned vehicle dynamics technician to be able to feel a difference in how the car feels. when fitting new wheels, you're far more concerned with the rubbing on arches or fouling suspension arms, but a 13mm difference in offset combined with the same width wheel will be absolutely fine.

[beanie]

For most people fitting wheels it’s a bit of a non issue in reality. I’d expect a slight change in feel but the sort of changes you’re making aren’t going to turn it in to some twitchy or unresponsive nightmare. Whether you find the change positive or not is another matter but I wouldn’t expect problems.

As an example, I went from a 195/50 6x15 et 33 wheel and tyre to a 195/45 8x15 et 14. No idea what the change in scrub radius was but the two setups were a fair way off each other. The result, the 6x15 was a far more road friendly setup and lighter on its feet but the 8x15 was still fine and didn’t make the car dangerous or in any way unpredictable-In fact, I’ve had worse effects from putting on wheels and tyres that were significantly heavier than those they replaced.

[minimental]

i found this explanation helpful at least to get a feeling of what effects it can have:
https://www.carthrottle.com/post/what-i ... important/