Since 2005, we have been outfitting the new asymmetric sleeves and collars to our sculling oars. After some minor engineering advances, we began using a slightly modified version of that asymmetric sculling sleeve in 2007. In early 2009, we shifted all production of sweep oars to the new asymmetric rowing sleeve. We no longer stock parts for earlier types of sleeves and collars. Since sleeves and collars are wearable parts, and we highly recommend that users replace them with the latest versions when that situation presents itself.
If you are ordering spare collars, the photos below should help you determine which one applies to your set of oars.
Traditional - Mark 1 (symmetric)
Asymmetric - Mark 2 (sculling version only)
Asymmetric - Mark 3
These were the traditional sleeves and collars with a "three-sided design," originally created for the macon oars. The three flat sides allowed a macon oar to be used on either the port or starboard side. Side-specific cleaver blades made the third side "moot." Because of boathouse fleet needs in North America, in particular the use of "blue clam" adjustment clip mechanisms, we continued to use this sleeve on the majority of sweep oars until early 2009. The three-sided style of sleeve takes the standard "blue clam." As of February 2009, we have migrated all sweep oar production to the new asymmetric sleeve. We no longer offer the traditional sweep sleeves or collars.
This version of the asymmetric sculling sleeve was designed to best accomodate the side-specific cleaver style blade. Once the three-sided sleeves were no longer necessary, the change in design reflects a focus on the two flat sides that determine square or feather position. Areas not involved in the square or feather alignment are rounded, to better facilitate rotation in the oarlock. A small flat space at the "front" of the sleeve allows for more effective square-blade drills. The sleeve is held together by eight small screws.We have a small stock available, but we generally recommend all new oars be outfitted with the Mark 3 design.
The current version of our asymmetric sleeve and collar reflects some operational advances since the inception of the Mark 2 design. The change in profile further improves handling in the oarlock and reduces some assembly inefficiencies that slowed our ability to meet demand. Both asymmetric designs improve oar handling, but the Mark 3 is more sustainable from a production standpoint for the S2 and S4 lines, lowering costs and increasing availability for our customers. The sleeve is held together by eight interlocking clips, integral to the design. Early versions of the rowing sleeve were held together by eight screws, but the most current uses the clips. This is our current production model for all S2 and S4 sculling oars, and as of February 2009 it is the standard design for our sweep oars. We will continue to offer the traditional sweep sleeves upon specific request for large programs who wish to keep consistency with older sets in their fleet, but we do urge programs to consider the wide acceptance of this design among Croker users at the elite level.
NOTE -- Updated July 25, 2008
In the spring of 2008, we fielded numerous inquiries from Croker users who had been unsuccessfully attempting to use excessively short overall lengths, inboards and boat spreads.
Upon further investigation, it came to our attention that certain persons unaffiliated with Croker were offering inaccurate suggestions in their presentations at coaches' conferences for rigging settings of our oars. Given that the information they provided was completely inconsistent with all documented successful use of Crokers, at all levels, we surmise the misinformation appears to either be the result of no actual use of Crokers by these persons, or a deliberate attempt on their part to stack any comparisons in favor of other products by providing ineffective numbers for Croker oars.
We encourage you to ignore these persons, and to reject their "advice" in favor of ours. The rigging numbers we provide are gleaned from successful crews across all levels of rowing.
We know that when you win with Crokers, you'll spread the word and that will grow our business. We don't need to trick you into rowing someone else's oars poorly. You should try all brands of oars as each company's official literature recommends. We're confident that we'll be the one you continue to work with.