Dealers and Tires

[blazer]

As I have mentioned in another post, I think that many BMW dealers are a bit behind the 8 ball on the S1K, if for no other reason than they have never dealt with a bike like this and the demographic it attracts.

Case in point. I was casually speaking with the tech at my local shop and tire pressures came up. He explained he delivered all S1Ks with 36f/42r psi, just as he would an RT, LT or GS. I told him that I was generally going with 34f/32r and he about crapped himself, and started talking all about mileage, chunking, stability, etc. I tried my best to explain the rationale, but I didn't make much progress - mostly due to my inability to articulate the reasoning.

Can anyone here do me the favor of breaking it down to a 4th grade level so that when this comes up again (and it will) I can explain it a bit better?

Thanks!

B-

[YELLOPER1L]

Can you explain it to me please? I am genuinely intrigued.

On the road I would typically go somewhere near to the recommended pressure around 40/34 or similar on virtually every bike I've ever owned. I thought you should only run pressures as low as you have stated for track use. Why run so low on the street?

The reason which I've always bought into is that at low tyre pressures the water shifting grooves In your tyre are partially closed and therefore won't shift water when you're riding in rain. If the pressure's too high the tyre won't operate well either as the ability to flex is reduced and your suspension has to work harder to compensate for the lack of damping effect from the tyre.

It might explain why I regularly get 5000+ miles to a rear tyre and some of the other guys on the forum are lucky to see 3k!