We spec the Mavic Aksium wheelset on all of our 700c bikes. We spec this particular wheel because we believe it has the more bang for your buck than every other training wheel on the market today. A little more info below, from Mavic themselves.

The ‘FTS Nose’ is an extension of the hub body that goes inside the freewheel body. The contact zone between the pawl and the FTS Nose is reinforced by 2 stainless steel inserts, which allows for manufacturing an all aluminium, mono-piece hub body. The pawls are centered exactly in the middle of the freewheel body.

Reinforcement of the area around each nipple hole by hammering to compress the material of this sensitive zone. The rim can be eyeleted on top to even more improve resistance.

Sealed cartridge bearings that are serviceable, mounted on a special axle featuring a "bearing support ring" to adjust play.

The special shape of the spoke end, on the thread, makes it impossible to loosen. The spoke stays tightly screwed into the nipple, no tension loss is occuring. As a benefit, the wheel keeps its original roundess for a long time, and does not get out of true.