The quality of the Velobike trainer adapter is excellent. The dropouts, bolts, cog, and spacers all feel very well made and solid.
Installing the dropout adapters increased my rear spacing to 135 mm. With my Wahoo KICKR, I simply used the standard 135 mm quick-release adapter and everything fitted and worked well.
The only part that required some fine-tuning was the chainline. Depending on the bike, you may need to experiment with the supplied spacers and their order to get the rear cog properly aligned with the chainring. Once aligned, the drivetrain runs very well.
On the KICKR, the setup has been superb. I use the bike as a single-speed setup with TrainerRoad in ERG mode, and it works very well for normal training. One thing to be aware of is during large drops in resistance, for example, going from around 100 W to 45 W for a recovery interval. Because there are no gears to shift, you sometimes need to adjust your cadence considerably to stay comfortable as the flywheel slows down. This is really a limitation of using a single-speed bike in ERG mode rather than an issue with the adapter itself.
Overall, I’m very happy with the adapter. It provides a very clean and solid way to use a track/single-speed bike on a direct-drive trainer without modifying the bike itself.