Why are new tyres non-grippy?

[Simple_Linctus]

So I’m about to pop out and get all four of my tyres changed (to dunlop sportmaxx rts if anyone cares).

And it’s pissing it down. Won’t be surprised if I encounter localised flooding.

This means when I drive back I’m going to have to be driving like a granny, because new tyres have fook all grip for the first couple of hundred miles, and it’s especially bad for the first fifty.

Makes me wonder - why ARE new tyres so slippery? Presumably it’s the same compound on the outside as the rest of it, and it’s not as if they’re super smooth compared to used tyres or anything as far as I can tell…

[running_coach]

Mold release compound plus a very thin layer of “overcooked” rubber where it was in contact with the mold.

[Colophon]

@runner pat

Mold release compound plus a very thin layer of “overcooked” rubber where it was in contact with the mold.

Tyre manufacturers say they don’t use mould release agents. You might find this thread interesting.

New tyres certainly have a different look and feel from old tyres: blacker, smoother, harder and shinier. I think it’s simply that after a bit of wear, the surface is softened and roughened, making it grippier.

[running_coach]

@Colophon

Tyre manufacturers say they don’t use mould release agents. You might find this thread interesting.

New tyres certainly have a different look and feel from old tyres: blacker, smoother, harder and shinier. I think it’s simply that after a bit of wear, the surface is softened and roughened, making it grippier.

Chem-Trend, supplier of mold release compounds.

Tire Rack.

As tires are cured, a release lubricant is applied to prevent them from sticking in their mold. Some of the lubricant stays on the surface of your tires, reducing traction until it is worn away.

[Colophon]

OK, it appears that it’s motorcycle tyre manufacturers that avoid using mould-release agents.

Mold release agents are common in automotive tires, but is no longer used by most motorcycle tire manufacturers. Back in the days of bias ply tires, mold release compounds were greasy and obvious. With the introduction of radial tires manufacturers began using lighter release agents…and in the middle of the last decade most manufacturers stopped using release agents altogether.

Dunlop…

“Thank you for taking the time to contact us with your Dunlop motorcycle
tire questions. Dunlop Motorcycle Tire does NOT use a “mold releasing
agent” during the production of our tires. When new tires are fitted,
they should not be subjected to maximum power, abrupt lean-over or hard
cornering until a reasonable run-in distance of approximately 100 miles
has been covered. This will permit the rider to become accustomed to the
feel of the new tires or tire combination, find the edge, and achieve
optimum road grip for a range of speeds, acceleration and handling use. Be
sure to check and adjust inflation pressure to recommended levels after the
tire cools for at least three (3) hours following run-in. Remember, new
tires will have a very different contact patch and lean-over edge. New
tires, mixing a new tire with an used tire, and mixing tread pattern
combinations require careful ride evaluations.”

Pirelli…

"Pirelli does not use mold release. Tires are shiny because the general buying public demands that visually a tire look cool, smooth, shiny, and new when they shop for tires in the rack at the dealer. We rely on the smoothness of the mold to get this appearance and to help the tire let go from the mold during production.

I like to say tires are like new shoes, MX boots, or a leather jacket as they need the proper break in time. Regarding getting heat into tires this follows the same idea, only time and friction will put the heat in. I have attached a copy of the brochure so you can read about break in suggestions in the technical area. Ride safe"

Only Michelin, among the major manufacturers, still use mold release to my knowledge…

"Thank you for your email. We appreciate the opportunity to serve you.

Concerning your question, Michelin has a mold release agent on all
motorcycle tires. This will cause the tire to be slippery in the first
few miles, but that goes away after the tire is scrubbed in. This normally
occurs in the first 25-50 miles or so. Until then, the rider should use
caution in riding the tire at accelerated speeds. Michelin always
recommends obeying the speed limits and using care whenever riding."

http://www.ducatimonsterforum.org/index.php?action=printpage;topic=55400.0

[Simple_Linctus]

Oddly enough, having now had them fitted I have not experienced the lack of grip I was expecting in the OP; these tyres are much better from the outset than the crap that was on. I didn’t push it (was totally right about localised flooding… hell it’s flooding all over the place, loads of roads cloased) but I can tell I am going to be able to FLY with these…