Monday, August 18, 2008

Wheels of the Week

Actually two pair, as they couldn't be split, kind of non identical twins.

Both used Dutch M5 hubs, fitted with Phil Wood and Co bearings. Front hub is the SP version, with the flanged rear. Why? The rear SP version isn't available yet (plus read further), and while both M5 front hubs share the same weight limit (there isn't one), the SP version just looks more robust, and the top hat inserts to carry the spoke heads has a lot more material behind it. We have never heard of problems with either, but prefer to err on the side of caution. Corporate preference is towards straight pull spokes also on front wheels due to the way the stresses work, so that's another reason. It's cleaner and stiffer. Rear hubs undergo different dynamic stresses, so the way a flanged hub works is actually an advantage here. We tested this using a mixture of machinery and on the bike use, and have found the results to be consistent. The difference is small however, and wouldn't prevent us building SP rear hubs under certain conditions.

Spokes are Sapim CX-Ray. They are nice spokes, available in SP form for the front from stock, and work well with the M5 hubs (no surprise, as they come from just over the border in Belgium). Nipples are 3/16" internal aluminum.

Rims on set #1 are KinLin XR-200, their 22mm deep box section Niobium alloy model. We have these drilled for internal nipples especially for this wheelset.

Rims on set #2 are KinLin XR-270, their 27mm deep aero section Niobium alloy model. Again drilled for internal nipples, they are a rim we use a lot of.

Weight for set #1 with 24/28 spokes is 1246gm/pr. Lighter than many carbon options of "climbing" style carbon rim clinchers without the high cost associated with carbon rims.

Weight for set #2 with 20/24 spokes is 1350gm/pr. These are a great "do anything" road wheelset. Century rides, racing, even Cross. They have some aerodynamic advantage without the weight penalties normally associated in mid-deep section clincher wheels, and aren't a problem to handle in cross winds.

Both sets get our vote for contenders as wheels of the year...