Instead I feel Bolt Blue! P Line 12 with a 44t chainring, but I'm already looking for a smaller one. There's hills and mountains where I am.
by SheriffSlug
Instead I feel Bolt Blue! P Line 12 with a 44t chainring, but I'm already looking for a smaller one. There's hills and mountains where I am.
by SheriffSlug
3 Comments
Love the leather color on the Brooks saddle! Really compliments the blue of the bike!!
👌
For gearing comparisons :
Brompton 12 speed sequential gearing calculations in inches (equivalent wheel diameter) (inflated diameter of a 35-349 tyre is nominally 16.6”) It is a new hub, but with the same BWR ratios of 0.64, 1.0, 1.57, as the 6 speed rear hub :
50T chainring :
Hub 1 30 35 41 48
Hub 2 46 55 64 75
Hub 3 72 86 100 118
44T chainring
Hub 1 26 31 36 42
Hub 2 41 48 56 66
Hub 3 63 76 88 104
40T chainring
Hub 1 24 28 33 38
Hub 2 37 44 51 60
Hub 3 58 69 80 94
The 40T ring would require a modification of the chain catcher, since the catcher bottoms out for the 44T chainring. The catcher block would have to be set about 7 mm lower than the OEM position of the chain catcher.
👌, the Brompton crank 130mm bolt circle smallest chainring technically is 38T, except you would probably have to devise a chain guard for a 38T or 39T. 40T with chain guard are in the Brompton aftermarket.
A complete change put of the cranks to a 110mm spider would allow for chainrings smaller than 38T.