sip speedo sensor mounting

Where's the best / easiest/ neatest place to mount the sip speedo sensor? I've just had the sensor and bracket delivered but can't see a suitable mounting point ( front disc fitted)
I've seen a neat bracket to fit on the rear shock mount on the casing that picks up one of the rear wheel nuts but don't fancy drilling the casing there..
I've seen a neat bracket to fit on the rear shock mount on the casing that picks up one of the rear wheel nuts but don't fancy drilling the casing there..