Why does urethane spin more?

[Hook DeLoft]

What are the physical differences that make a urethane covered ball spin more than an ionomer covered ball? Friction?  Softness?  Coefficient of restitution?

[DaveP043]

I believe technically it classifies as "magic".

[adamflowers]

My understanding is that the urethane cover is softer, and this allows for more friction on the clubface, i.e. more spin.

[Middler]

2 minutes ago, adamflowers said:

My understanding is that the urethane cover is softer, and this allows for more friction on the clubface, i.e. more spin.

Yep.

Quote

Urethane covers are softer than surlyn, thus allowing the cover of the golf ball to dig more into the grooves of a wedge.

 

[DiscipleofPenick]

SCIENCE!!!!!!!!

Take Dead Aim

[GregGarner]

8 hours ago, adamflowers said:

My understanding is that the urethane cover is softer, and this allows for more friction on the clubface, i.e. more spin.

If I understand correctly, the softer urethane cover by itself adds some spin, but it's more due to the softer cover being on top of a firmer ionomer mantle that really adds the spin. This is why you don't see a 2-piece urethane ball, because it wouldn't have the same ability to "grip" against the core. And why basically all ionomer balls are 2-piece, because the mantle would need to be firmer than the cover.

...I think

 

[adamflowers]

yep, I believe that soft-hard combination is correct.

[ZenGolfer]

Its my understanding that its because its softer, so it has more friction and spins more as it rides up the clubface at impact.  It works much the same as how soft tires do on a racecar.  That also explains why surlyn balls tend to be more durable: harder cover.

[NRJyzr]

On 8/9/2020 at 7:02 AM, Middler said:

Yep.

 

 

It's friction, but it's not the grooves.  Early tests with grooveless clubfaces produced more spin on clean contact.

[Hook DeLoft]

Thanks for the responses.

[null]

On 8/9/2020 at 4:19 PM, greggarner said:

If I understand correctly, the softer urethane cover by itself adds some spin, but it's more due to the softer cover being on top of a firmer ionomer mantle that really adds the spin. This is why you don't see a 2-piece urethane ball, because it wouldn't have the same ability to "grip" against the core. And why basically all ionomer balls are 2-piece, because the mantle would need to be firmer than the cover.

...I think

 

This guy knows what he's talking about.

There is a myth that softer compression urethane balls spin more then firmer compression urethane balls and that is absolutely not the truth.

It all depends on the layer differentials (ie the softer cover working against the firmer layer underneath it)