Sym vs Asym

Bowling ball related topics including new products, arsenals and comparisons.

Moderator: Moderators

TomaHawk
Pro Shop
Pro Shop
Posts: 587
Joined: July 19th, 2010, 3:28 pm
Location: Michigan

Re: Sym vs Asym

Post by TomaHawk »

EricHartwell wrote: March 26th, 2021, 1:08 am The faster the spin, the greater the forces.

There are 2 axis locations where these forces are the strongest.

The Low Rg Axis, the Pin.

The High Rg Axis, The Mass Bias/PSA.

In Highly Asymmetrical bowling balls the PSA will be much stronger which in my mind correlates to more gyroscopic effect...
It allows the ability to resist or assist gravity.
Which spins faster with the least amount of force? Asym or Sym
User avatar
MathIsTruth
Industry Professional
Industry Professional
Posts: 548
Joined: January 19th, 2010, 5:18 pm
Preferred Company: MoRich/Radical
Location: Washington, WV

Re: Sym vs Asym

Post by MathIsTruth »

EricHartwell wrote: March 23rd, 2021, 11:09 pm Because of the PSA, the Mass Bias strength. The stronger it is the greater the gyroscopic effect and how it influences Tilt.

I shouldn't have said, "does not exist with Symmetricals" , but rather is very weak in Symmetrical balls.
I would like to add that the strength of the Int RG axis also plays a huge roll which is more of the reason why Symm balls have less gyroscopic effect.
User avatar
MathIsTruth
Industry Professional
Industry Professional
Posts: 548
Joined: January 19th, 2010, 5:18 pm
Preferred Company: MoRich/Radical
Location: Washington, WV

Re: Sym vs Asym

Post by MathIsTruth »

TomaHawk wrote: March 24th, 2021, 12:51 am The polarity of a weight block, core design, has a lot of influence too.
We have said numerous times that core shape matters and it couldn’t be stated enough so I appreciate your post. The geometric shape has everything to do with the amount of gyroscopic potential that can be achieved with a bowling ball. This topic is one of the areas that I was most excited to learn about with the cores Mo and I built over the last 13 years. I figured out a way to measure that potential years ago so Mo and I pushed each other to understand what changes in core shapes did to that potential. Sometimes subtle changes would affect that potential. The development of Radical cores was special in that way because we had 3 criteria to hit when we designed our cores; undrilled mass properties, drilled mass properties like the 70/3.5”/20 layout, and the gyroscopic potential value. Core shape matters.
User avatar
EricHartwell
Trusted Source
Trusted Source
Posts: 4080
Joined: April 5th, 2011, 12:24 am
Positive Axis Point: 4-3/4" and 1/2"up
Speed: 16 off hand
Rev Rate: 330
Axis Tilt: 12
Axis Rotation: 45
Heavy Oil Ball: Radical Tremendous, EVO solid, Hammer Obsession
Medium Oil Ball: EVO pearl, True Motion, Columbia Command, DV8 Intimidator
Light Oil Ball: Blue Hammer
Location: Michigan

Re: Sym vs Asym

Post by EricHartwell »

TomaHawk wrote: March 26th, 2021, 2:04 pm Which spins faster with the least amount of force? Asym or Sym
Interesting question. I don't know the answer for sure, but...
Off the top of my head I would say it would depend on the Rg of the PAP not whether it was Symmetrical or Asymmetrical.
Eric Hartwell

Right Handed
PAP 4.75" up 1/2"
45* rotation
12* tilt
330 rev rate
16 mph off hand
User avatar
deanchamp
Trusted Source
Trusted Source
Posts: 455
Joined: August 4th, 2010, 10:23 am
THS Average: 220
Location: Melbourne, Australia

Re: Sym vs Asym

Post by deanchamp »

That was my initial thought too, the RG of the PAP once the ball is drilled would influence how 'fast' something would spin with the same force applied.
USBC Silver Level Coach
BCU Graduate - Mastery of Layouts
BTM contributor
User avatar
TheJesus
Member
Member
Posts: 190
Joined: July 14th, 2017, 11:00 am
Speed: 17mph (foul line)
Rev Rate: 330
Axis Tilt: 12
Contact:

Re: Sym vs Asym

Post by TheJesus »

Thanks for trying Eric. :)
Check out my bowling related YouTube channel ! BOWLING XP ! https://www.youtube.com/channel/UC1cTYc ... Eynuk0qdIw :mrgreen:
User avatar
TheJesus
Member
Member
Posts: 190
Joined: July 14th, 2017, 11:00 am
Speed: 17mph (foul line)
Rev Rate: 330
Axis Tilt: 12
Contact:

Re: Sym vs Asym

Post by TheJesus »

MathIsTruth wrote: March 26th, 2021, 5:45 pm We have said numerous times that core shape matters and it couldn’t be stated enough so I appreciate your post. The geometric shape has everything to do with the amount of gyroscopic potential that can be achieved with a bowling ball. This topic is one of the areas that I was most excited to learn about with the cores Mo and I built over the last 13 years. I figured out a way to measure that potential years ago so Mo and I pushed each other to understand what changes in core shapes did to that potential. Sometimes subtle changes would affect that potential. The development of Radical cores was special in that way because we had 3 criteria to hit when we designed our cores; undrilled mass properties, drilled mass properties like the 70/3.5”/20 layout, and the gyroscopic potential value. Core shape matters.
Interesting. Could you offer an example of 2 cores that have different shapes but same RG/DIFF and what their possible differences can be on the lane ? Thanks ! :)
Check out my bowling related YouTube channel ! BOWLING XP ! https://www.youtube.com/channel/UC1cTYc ... Eynuk0qdIw :mrgreen:
56bird
Member
Member
Posts: 488
Joined: April 18th, 2013, 11:55 am

Re: Sym vs Asym

Post by 56bird »

Interesting yet I still don’t feel like the question is really answered. The subject of the video is spot-on but if it is addressed I’m missing it.

The bit about skid phase being longer on an asym is interesting. I’m not so sure about that but he’d know better than I would.

User avatar
snick
BCU Graduate Layouts
BCU Graduate Layouts
Posts: 759
Joined: August 31st, 2014, 8:00 pm
THS Average: 196
Sport Average: 180
Positive Axis Point: 5.5625" x .625 up
Speed: 17 off hand
Rev Rate: 360
Axis Tilt: 17
Axis Rotation: 55
Heavy Oil Ball: Storm Physix
Medium Oil Ball: Storm Streetfight
Light Oil Ball: Rotogrip Hustle Pearl
Preferred Company: Rotogrip
Location: Tucson, AZ

Re: Sym vs Asym

Post by snick »

Asymms can potentially have a sloped, gradually increasing flare profile.
ie: 6" pin-pap can flare more than a 4" pin-pap

Symms always have a bell-shaped flare profile.
ie: 4" pin-pap is more or less max flare.

Asymm for Bowlers that need both long pins and high flare.
Asymm for bowlers that need to use low angle ratios for their benchmark layout.
Asymm for long heavy patterns that require low angle sums and faster recovery.

My own general rule of thumb for pin-PAP is to convert the pin-PAP distance to core angle, and match that core angle to the bowler's axis rotation angle, then adjust it slightly up or down to compliment their axis tilt angle and expected post-drilling low-RG axis shift.
ie: 60 degrees of axis rotation generally correlates with a 4.5" pin-PAP (60 degree core angle), while 45 degrees of axis rotation might match up better with a 3.75" pin-PAP (45 degree core angle).
Benchmark Bowling Pro Shop
Byron

RH
PAP: 5.5625 x .625 up
REVRATE: 360
SPEED: 17mph at release
AR: 55º
AT: 17º
User avatar
MegaMav
Moderator
Moderator
Posts: 4694
Joined: April 27th, 2007, 5:00 am
THS Average: 225
Sport Average: 200
Positive Axis Point: 5.5 Over & 1 Up
Speed: 16.0 MPH - Camera
Rev Rate: 375
Axis Tilt: 14
Axis Rotation: 45
Heavy Oil Ball: Radical - Informer
Medium Oil Ball: Brunswick - Fearless
Light Oil Ball: Radical - Bonus Pearl
Preferred Company: Radical Bowling Technologies
Location: Malta, NY

Re: Sym vs Asym

Post by MegaMav »

I've kept it real simple for me, personally.
Symmetricals outside 15 at the arrows, asymmetricals inside 15 at the arrows. :)
User avatar
EricHartwell
Trusted Source
Trusted Source
Posts: 4080
Joined: April 5th, 2011, 12:24 am
Positive Axis Point: 4-3/4" and 1/2"up
Speed: 16 off hand
Rev Rate: 330
Axis Tilt: 12
Axis Rotation: 45
Heavy Oil Ball: Radical Tremendous, EVO solid, Hammer Obsession
Medium Oil Ball: EVO pearl, True Motion, Columbia Command, DV8 Intimidator
Light Oil Ball: Blue Hammer
Location: Michigan

Re: Sym vs Asym

Post by EricHartwell »

snick wrote: May 3rd, 2021, 8:37 pm Asymms can potentially have a sloped, gradually increasing flare profile.
ie: 6" pin-pap can flare more than a 4" pin-pap

Symms always have a bell-shaped flare profile.
ie: 4" pin-pap is more or less max flare.

Asymm for Bowlers that need both long pins and high flare.
Asymm for bowlers that need to use low angle ratios for their benchmark layout.
Asymm for long heavy patterns that require low angle sums and faster recovery.

My own general rule of thumb for pin-PAP is to convert the pin-PAP distance to core angle, and match that core angle to the bowler's axis rotation angle, then adjust it slightly up or down to compliment their axis tilt angle and expected post-drilling low-RG axis shift.
ie: 60 degrees of axis rotation generally correlates with a 4.5" pin-PAP (60 degree core angle), while 45 degrees of axis rotation might match up better with a 3.75" pin-PAP (45 degree core angle).
Several good points

I hadn't given thought to core angle and axis rotation and in looking back the layouts I've recommended I adjust Pin to PAP to accommodate both Tilt and Rotation, my adjustments are very much in line with how you explained and now I understand a bit more why, thank you.

To expound a little further...
Asymmetrical balls and low ratio layouts, the flare pattern will have more distance between the flare lines in the oil and less on the back end.
Where as High Ratio layouts will have more flare on the back end.
1:1 ratios will have more even flare distribution
These flare patterns contribute to the shape of the ball motion.

It is about how you position the pin to spin line in respect to the initial track then manage the speed to rev relationship with flare potential of the ball you are drilling.
Things you just can't do with Symmetrical balls.
Eric Hartwell

Right Handed
PAP 4.75" up 1/2"
45* rotation
12* tilt
330 rev rate
16 mph off hand
User avatar
snick
BCU Graduate Layouts
BCU Graduate Layouts
Posts: 759
Joined: August 31st, 2014, 8:00 pm
THS Average: 196
Sport Average: 180
Positive Axis Point: 5.5625" x .625 up
Speed: 17 off hand
Rev Rate: 360
Axis Tilt: 17
Axis Rotation: 55
Heavy Oil Ball: Storm Physix
Medium Oil Ball: Storm Streetfight
Light Oil Ball: Rotogrip Hustle Pearl
Preferred Company: Rotogrip
Location: Tucson, AZ

Re: Sym vs Asym

Post by snick »

I am happy to hear your assessment of my assertion. I have found you to be a consistently excellent resource over the years. Cheers.
Benchmark Bowling Pro Shop
Byron

RH
PAP: 5.5625 x .625 up
REVRATE: 360
SPEED: 17mph at release
AR: 55º
AT: 17º
Post Reply