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TW Professor
12-07-2010, 11:06 AM
Check out the new experiment to determine the sliding friction between strings and its relation to spin:

Spin and Sliding Friction (http://twu.tennis-warehouse.com/learning_center/slidingCOF.php)

Previous tools and experiments dealt with static friction:
Static Friction and Spin (http://twu.tennis-warehouse.com/learning_center/COF.php)
String Friction Tool (http://twu.tennis-warehouse.com/learning_center/COFreporter.php)

Static friction relates to the force necessary to get the string moving and sliding friction is about the force necessary to keep it moving.

Eventually, the coefficients of sliding friction will be incorporated into the string friction tool also and more strings will be added to both.

julian
12-07-2010, 12:45 PM
Check out the new experiment to determine the sliding friction between strings and its relation to spin:

Spin and Sliding Friction (http://twu.tennis-warehouse.com/learning_center/slidingCOF.php)

Previous tools and experiments dealt with static friction:
Static Friction and Spin (http://twu.tennis-warehouse.com/learning_center/COF.php)
String Friction Tool (http://twu.tennis-warehouse.com/learning_center/COFreporter.php)

Static friction relates to the force necessary to get the string moving and sliding friction is about the force necessary to keep it moving.

Eventually, the sliding COFs will be incorporated into the string friction tool also and more strings will be added to both.
Sir,
it would be a good idea to avoid using acronyms
respectfully,
julian

TW Professor
12-07-2010, 01:17 PM
Sir,
it would be a good idea to avoid using acronyms
respectfully,
julian

Sorry. I agree...especially without any previous reference! I changed it.

TimothyO
12-07-2010, 03:25 PM
Thank you for feeding my inner geek!
:)

Great stuff, really looking forward to more research!

Please, please, please put VS + Xcel hybrid on your list of things to test!

Consolation
12-07-2010, 04:12 PM
Also, timing is crucial. How long it takes to get the string moving, how far it moves, and when, how far and with how much ball contact it snaps back are all important to the final spin effect. String movement by itself does not necessarily equate with spin, but it is as good a predictor that we have. Future experiments will measure the spin of various strings and combinations to more accurately determine the correlation between static and sliding friction and spin. At this time, we can say that strings with lower static and/or sliding coefficients of friction are more likely to create more spin.

Not sure about the bold part. You do a good job of mentioning the limitations of the data you have, then go ahead and make a causal statment anyway =).

This is great stuff you're doing, but it's a little spooky how quickly the static friction article became gospel to so many on this board as being a clear and definitive reference for which strings make more spin.

Even the very first article you posted (http://twu.tennis-warehouse.com/learning_center/stringmovement.php) shows things are much more complicated (multiple strings showed increase in spin at higher tensions, with higher COFs).

Anyway, hoping this latest list doesn't become the new definitive source for people to quote as to what the best string combo is...

julian
12-07-2010, 06:06 PM
Check out the new experiment to determine the sliding friction between strings and its relation to spin:

Spin and Sliding Friction (http://twu.tennis-warehouse.com/learning_center/slidingCOF.php)

Previous tools and experiments dealt with static friction:
Static Friction and Spin (http://twu.tennis-warehouse.com/learning_center/COF.php)
String Friction Tool (http://twu.tennis-warehouse.com/learning_center/COFreporter.php)

Static friction relates to the force necessary to get the string moving and sliding friction is about the force necessary to keep it moving.

Eventually, the coefficients of sliding friction will be incorporated into the string friction tool also and more strings will be added to both.

How dunlop silk fit into this picture?
http://www.tennis-warehouse.com/Dunlop_Silk_17_String/descpageACDUNLOP-DSILK17.html

Guardian
01-11-2011, 01:24 PM
These numbers presented are very interesting! Looking at the data, Babolat Pro Hurricane Feel 16 catches my eye with the lowest sliding COF and a reasonably low static COF. Anyone tried this string?

jester911
01-11-2011, 01:32 PM
I don't see how it is spooky that the he static friction article has caught on this much. For me it just confirmed what I suspected for a long time and I think many others were in the same boat.