Depending on hub, cones might be threaded for M10x1.0 axle instead of M9x1.0. May need some kind of step down axle job.
Example: Deore M510 rim brake hub has M9 axle but Deore M525 & XT M756 use M10.
I think a 10mm axle will fit in the dropouts as I've used a track wheel in there previously.
Track front hubs are 9mm. If a 10mm axle fits in your 9mm dropouts, they are fucked. The 756 axles are 10mm threads but necked down to 9mm at the dropout, so a 10mm solid axle should not fit your dropouts.
Depending on hub, cones might be threaded for M10x1.0 axle instead of M9x1.0. May need some kind of step down axle job.
Example: Deore M510 rim brake hub has M9 axle but Deore M525 & XT M756 use M10.