Bought 2 nw rings for the kids bikes came to fit them and I’ve realised that as they’ve got single ring cranks that I can’t fit them as they need to be flat.

Can you get flat 104 BCD 30t rings that don’t cost a fortune?

Or could I just use really long chainring bolts

This might sound daft for folk who’ve seen these rings, but is this an issue that the right size of drill to remove the threads would sort?

Cheap drill press attachment for your drill if you want to keep I straight.

Bolts for two rings at a time (triples) ought to be long enough.

PS – Or turn the ring round maybe? NW chainring so it doesn’t matter which way it runs?

And if that fails – 32t?

https://www.google.co.uk/aclk?sa=L&ai=DChcSEwin_J_Q_93vAhWHR5EFHaO4D3UYABATGgJscg&ae=2&sig=AOD64_0myOSwQO3U29o5_fkUWQ9lIjGT2Q&ctype=5&q=&ved=2ahUKEwiW9JrQ_93vAhUny4UKHaX9B6IQwg96BAgBEEU&dct=1&adurl=

If memory serves, the point of 30t 104 rings being threaded is that 32t is the smallest that will allow the chain the clear the chainring bolts.

30t needs to sit off the spider a little (also means a slightly better chain line in lower gears).

Onzadog is correct in terms of the bolts. I think I fitted a 28t once but that was a special order from that there USA – I am assuming there is something special about the cranks that means this isn’t possible?

Would be useful to know more about the crank. In my mind, I’m imagining a crank arm tab with a blind threaded hole that the bolt goes into from the Centreline of the bike.

Thanks for the replies, it never occurred to me as I’ve used 30t before converting standard chainsets to NW that it would work. The each crank arm has has threaded hole and the chainring is bolted in from the back.

I don’t see why in this case a flat ring wouldn’t work. Might try to macgyver something putting the ring on backwards and using longer m8 bolts. What could possibly go wrong.