The Quest front chain ring is 30-42-53 and 170 mm crank length.
In high gear I’m spinning out (~90 rpm) around 33 mph in the large chain ring and about 26 mph in the middle chain ring.
I emailed Randy at BlueVelo about bumping up the gearing to something like the Lightning F-40 and got this response:
Hi Dan, Randy here. You were asking in the voicemail about a 60 t front chain ring if I’m not mistaken. The 60t may be an issue with the huge jump from the 42 middle ring. It would also mean adding a bunch of extra chain that would lead to major slack issues when in the smallest ring. I would recommend a 56t which can work out without so many issues and will still make a decent shift up from the middle ring. I heard of using a 57t but that is again a bit too much in my opinion. To go to a 60t would be possible but not without changing to at least a 44 middle to make the shift and a 32 or 34t smallest ring to avoid the chain slack issues. I don’t have any different size front rings in stock at the moment. You would be looking for front chain rings with a 5 bolt pattern, 9 speed and 130mm for the middle and largest rings. The smallest ring is a 5 bolt pattern, 74mm. I know some people have used the Vuelta USA site to find a wide range of quality rings at good prices. Here is the link: http://www.vueltausa.com/components/chainrings.html You would likely find it faster and cheaper to go directly through a site like that for these parts with the specs I’ve provided. Let me know if I can help you with anything else to work through this. Thanks very much, Randy bluevelo
Based on this input I’ve decided to go with a 30-46-58 front setup. This will make the front middle chain ring viable up to about 30 mph and then kick it into high gear which should be good for cruising around 40 mph. At least on a slight downhill :)