4x4 CNC Router build. 45hsr rails?

I got a really good deal on 2 hsr45 rails with 2 bearings for each. I'm thinking about using them for my cnc router build , do you guys think this is a bad idea, they won't be used on the moving gantry only on the frame part.
Any input would be greatly appreciated.
Thanks Mike

They may have more friction / require more motor torque. Depends partly on the preload.

I would happily use them for a router.

(I would go and pay lots of $$ as they are overkill but you already said you got them cheap)