Hi,

I'll near guarantee its a one piece chainring and to change
the number of teeth the whole crankset needs changing.

My folder has 48 teeth. 52 is 8.3 % higher.
A freewheel starting at 13 instead of 14 would add 7.6%.

An amazing difference ? I don't think so. Each is about
half a gear on my 6 speed, together another gear.
48 with 14, 16, 18, 21, 24, 28. 33 to 66 gear inches.
Gears are 14%, 12.5%, 16.7%, 14.2%, 16.7%.

rgds, sreten.

I don't know how the clueless KHS person reckons
a 6 speed can be upgraded to 8 speed, just wrong,
and 7 speed freewheel is pointless, it can go no faster
than a 6 speed, both limited to a small 13t sprocket.