my apology. try this now.

http://www.bikepartsusa.com/bikepart...wheel_cassette

if this doesn't work go to www.bikepartsusa.com and select freewheels/cassettes on the left column.

the 7 speed will fit. the only problem is you have to change almost everything. and not sure if you want to do that. i looked everywhere but couldn't find a drop in replacement. if i decide to do the 7 speed 11-34T, i will have to change the rear hub, derailleur, rim, spokes and lastly the shifter. i am planning on doing this upgrade to my dahon. if you can find a dahon boardwalk D7 that would be ideal as it has a 11-30 7 speed gears and the chainring is 52T. very ideal for the speed you want. sometimes you can find this in CL. not sure if you want to buy a used one tough, but for the price you will be paying, you will have enough extra cash for all the upgrades you want. i am now ordering my parts one at a time and when i have them all with me, i will let you know the progress of my upgrade.

thanks,
vic