need gears explained in a laymans term

[jackthelad]

Hi looking at a brompton for the wife,and need gears explained,she hopes to use it for island hops and 1-2 day touring. Scotland is very hilly and looking to accommodate for them.Does she get a 6 speed with -12% on a front 44t or a 50t, what does this relate to in mtb gears with triple at front say (50.39,30 and a 11/32 at the rear.By explaining and relating to the mtb gearing she will understand, so any help appreciated,so I can get a bit of peace --- thanks

jackthelad

 

[Tigerbiten]

The standard set up is roughly equal in range to a 42 front and 11-14-18-22-27-34 back.
The top gear is 100" so you'll spinout at ~30 mph.
The 12% smaller is roughly equal in range to a 38 front and 11-14-18-22-27-34 back.
The top gear is 88" so you'll spinout at ~25 mph.
There's about half a gear between the two ranges.

With a full MTB triple, you'll probably be missing the top 2 and bottom 3 gears with the higher range and the top 3 and lower 2 gears with the smaller range.
And every other gear in the middle of the range ......... :P

 

[jackthelad]

Tiger thanks for explaining, she is happy on the flats cyclinga (39)(11,12,14) and looking at your explanation she has plenty of low gears for hils

 

[Brommyboy]

Standard Brompton gearing is too high for touring. Even the 44T 6-speed could be improved on. Unfortunately Brompton do not supply a better chain wheel: for me a 42T would be ideal, but my Welsh friend uses a 38T for his steep climbs. However, Scottish hills are longer but less severe than the Welsh ones, so the 44T 6-speed is the best available option.