Originally Posted by
vas jr.
The 49X14 or 49X15 Gear Ratios end up seeming really slow with 20" wheels, so I am looking for an x-large chainring.
@vas: what do you consider to be an X-Large chainring?
I think the Dura Ace and Campagnolo track cogs go down to 13 T. (I even have a 12T Campagnolo, but it seems to have a smaller diamerter than the standard track-hubs.)
The 13T cog will give you some more speed but probably still not enough. I ride 13Ton 54T on
my Swift what I find very convenient. Still: Chainrings larger than 52T are hard to find. But I think 13Ton 52T are widely available and will also do fine on a fast bike.
If you still need more speed you might consider to get the ring custom manufactured. The wicked 72 T chainring on my
Auto Mini Folder did cost me barely 35 Euros. A very nice guy in germany did it for me on his laser-cutter...