Rear Disc wheel for ... less than 7000 yen?

Inspired by MOB's reminder of the TT world championships, I decided on Saturday to try a product that I got recently from wheelbuilder.com along with my new Velocity A23 rim/White Industry hub wheels.  It is an "aero jacket" cover for my HED Jet 6 rear wheel, converting the already-aerodynamic wheel into a super slick disk for TT and triathlon use.  The product is cut and drilled specifically to fit my wheel, including an inquiry as to whether I had 24 or 28 rear spokes, to make sure that the fasteners don't hit any spokes.  And the cost, only $89, or about 6700 yen.

Shipping charges would increase that substantially ... so best to order as an accessory that can fit in the same package as a wheel set.  Maybe this is something one of our favorite LBS's would want to offer in Japan?

There is an adhesive cover to place over the cutout for the valve stem -- not yet attached.

This photo showing right/cassette-facing side.

Do I ride TT's or triathlons?  No.  But someday.  ...

It took quite awhile to tighten the plastic fasteners so that the cover is firmly attached against the spokes.  And the fasteners look pretty flimsy -- I cannot imagine I can take them on and off very many times without damaging them (but a spare set costs only $7.50 ... 600 yen).  The plastic aero jacket itself looks reasonably durable and should hold its shape nicely, though it comes with a warning that it is not intended for regular training use -- save it for race day.

I rode these wheels up and down the Tamagawa on the Friday holiday afternoon.  I really noticed a difference, especially coming back down the road along the Kawasaki side.  Yes, I rode this stretch awhile back with Steve T., holding a high average speed as I gave it my all.  But this time, I was not pushing it into the "red zone", and could still hold the speed at 41-42 kph for long stretches without much wind.  Nice.