6 January 2006
To:

ALL MANUFACTURERS

MEASUREMENT OF CHARACTERISTIC TIME ENCOMPASSING CLUBS OF ALL LOFTSI am writing further to my memorandum dated 24 March 2005 when I invited your commentson our proposal to routinely measure the 'spring-like' effect of all clubs of all loft (excludingputters). This proposal was prompted by a noticeable increase in the trend for designinghigher lofted clubs with a high ‘spring-like’ effect. The purpose of this communication is toupdate you on The R&A’s latest position on this matter.
All of the comments received from manufacturers as a result of my March memorandum havebeen carefully considered and further investigative work has been carried out. We now
believe that our original proposal, to apply the same characteristic time test methodology to
all clubs of all lofts (excluding putters), is not entirely appropriate. Whilst the application of thecurrent limit and testing method with the modified pendulum remains pertinent to clubs suchas fairway woods and hybrids, it would be overly penal for iron clubs.
In conjunction with the United States Golf Association (the “USGA”), we have developed arevised method for measuring the ‘spring-like’ effect of irons using the modified pendulum
which de-lofts the club. However, we wish to conduct additional testing on the revised
method and, until this is completed, The R&A’s Equipment Standards Committee has decided
to adopt the following interim procedures:
1. From 1 February 2006, all non-iron clubs (excluding putters) will be measured on theappropriate pendulum tester (see table below) and the current limit of 239 microseconds,
plus 18 microsecond tolerance, will apply. This category of club will cover any club which is
not considered to be a ‘traditional’ iron club and will include driving clubs, fairway woods
and hybrids.
2. From 1 February 2006, iron clubs will be screened using the modified pendulum tester and, if
necessary, they will also be tested using the cannon test at an appropriate velocity (i.e. 133ft/s). Iron clubs which measure more than 0.008 above a baseline plate will be ruled nonconforming (for further details, see copy of the test protocol attached). During this interimperiod, no iron club will be ruled non-conforming based purely on its pendulum test result.
For the avoidance of doubt, a summary of the situation regarding the regulation of ‘springlike’ effect in all clubs (excluding putters), from 1 February 2006, will be as follows:Club Type

Test Method

Driving Club

Pendulum

Fairway woods,
hybrids and all other‘non-irons’
Traditional Irons

Modified Pendulum

Modified Pendulum (as ascreening method); cannon test
if necessary

239 µs (plus 18 µstolerance)
239 µs (plus 18 µstolerance)

Introduction
Date
1 January2008†
1 February2006

0.008 above
baseline plate

1 February
2006

Limit

† This Rule is already in use at the professional and elite amateur level via the Driving Club

Condition of Competition.

Please let me know if you have any questions or concerns regarding the above. Technicalqueries concerning the protocol should be directed to Dr Steve Otto (steveotto@randa.org).
Yours faithfully

DAVID RICKMAN
Director of Rules and Equipment Standards