The best option for the Yamaha YZF R125/R7 is our Fork Stem Mount. However you'll need to replace the Top Yoke Nut with an open nut like below. Google Top Yoke Nut for - R125/R7 to find shops which sell the nut you'll need. We'd recommend taking your bike to a dealer or service shop to have the nut replaced as it requires a large socket and needs to be torqued up to the correct settings. 

So you can go from this...

To this.