I have a set of Bontrager Big Earl wheels off my ~2007 Trek Session 7 sitting collecting dust so I thought I would try and use them in an upcoming urban bike build. The front is 20mm and the rear is a 135mmx10mm QR. I want to convert the rear axle from QR to 10mm bolt-on thru-axle. I have searched and searched and cannot come up with anything. I found a thread that points to the hub possibly being a Formula design; are Formula axles going to be the ticket and what size? Will a standard Shimano conversion axle do the job?

Any help would be GREAT.