Originally Posted by
Beemer
Can anyone tell me what is the largest freewheel cog that I could fit to my Brompton H6?
My Brompton H6L has the BWR Hub and two speed dérailleur.
So gearing is 50T front and 16/13 rear which with 16" Schwalbe gives:
32.5/40/50.9/62.7/79.8/98.2 inches
I need the range to be lower and higher
A 53T front with the same rear would give me 35.1 to 106 inches but not low enough
A 53T front with a 20/13 rear would give me 27.6 and 104.1 inches
This would suit me fine but I guess that 20/13 is an impossible dérailleur change.
So looks like a Schlumpf Mountain Drive with the standard 52T/16/13 is the solution?
13.6 to 103.7 inches
Ian
seems legit:
E.3.5.1. high-speed-drive for Brompton folding bike
" A very popular combination is the Brompton folder combined with high-speed-drive. It needs a +6.5mm cone ring to allow folding (the rear chainstay folds where normally the gear housing is located) and a wider nut on the left side to make up for the additional width.[/I]
A good set-up is the standard high-speed-drive with its 27t. chainring and integrated trouser guard. With such a chainring, you have much lower gears for climbing (27 instead of 50t.) but also much higher gears for speed (67 instead of 50t.)."