Somewhere I have in my head the front sprocket should be 186Nm but then again perhaps I am way out, sprockets on other bikes I have fiddled with were never that tight surely? Thanks.
You memory hasn't let you down Bradders: CHAIN - FRONT SPROCKET Sprocket retaining nut M25x1.5 186 ± 5% GREASE B
I've not owned a torque wrench until recently, so I always went 'full english' on the front sprocket. I believe that is equal to around 186nm or thereabouts.
If you're using a 24 inch breaker bar it's just 68 pounds of force on the end. Not that hard to do. If you're tightening with all your might with such a bar you're way over tightening it