Hi I'm thinking of building a single speed and wheels come with 18t freewheel in the back and wondering if 46 T chain set is okay? I had Tibial plateau fracture 3 months ago and can't wait to get these Quads working.the area around me is relatively flat.but I'm not hardcore cyclist.not overweight don't have physical therapist so trying to get on the roads again to strengthen my thighs.patella area is a bit weak.whatsbthe average speed on 46Tx18T sprocket? Tanks