Folding Bikes - How to shift 6 speed brompton

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View Full Version : How to shift 6 speed brompton


Barrakulyan
04-13-12, 08:04 AM
I wasn't sure how you exactly do it. Do you just shift threw the First three gears then switch over the derailer and start over again? or is it something more complex like switching both shifters back and forth 6 times.

Asking this cause I'm trying to decide whether to go with 3 or 6 speed. I want the option of 6 speed since i live in hilly areas.

I did look but maybe I was using bad keywords.


Lao
04-13-12, 09:17 AM
You can say that you have 3x2 speeds and you gear as follows:
Ex 1 In 1 = 1
Ex 2 In 1 = 2
Ex 1 In 2 = 3
Ex 2 In 2 = 4
Ex 1 In 3 = 5
Ex 2 In 3 = 6

(Ex = External = left shifter ---- In = Internal = right shifter)

It may sound difficult but it isn't while you actually shift so there should be no problems. :)

Barrakulyan
04-13-12, 10:12 AM
Ok cool, I kinda thought it was something like that. The right side shifter hates down shifting (fights me when I try to downshift) I guess i have to ask why is it like that? I feel like im gonna break it. I guess they designed it to be that way?


Purpleorchid
04-13-12, 10:41 AM
The LBS told me this:
Right shifter = don't pedal while changing gears
Left shifter = pedal while changing gears

That means if you forget to downshift before coming to a stop, you can just change to a lower gear on the right shifter while stopped so it's easier to get going again.

chagzuki
04-13-12, 10:56 AM
I figured with the Brompton 6 speed setup one would want to shift both simultaneously otherwise the system would be very untidy? My SA hubs shift under light pedalling pressure.

fietsbob
04-13-12, 11:11 AM
The LBS told me this:
Right shifter = don't pedal while changing gears
Left shifter = pedal while changing gears

Yea as it's a hybrid, 2 cogs, on an IGH , so to go between the 13t & 15t,
the chain has to be moving.

internal gear change just needs a slight hesitation in power application,
to let the mech work.

Change the IG, then if its a bit high or low, shift the cogs

Being in the 13 and climbing , as with all derailleur bikes
needs a bit of reduced chain pull to make the slack to
climb up to the bigger cog...

If you had double chainrings , it would be the same issue.

Read the terrain, and plan ahead.

Purpleorchid
04-13-12, 11:18 AM
LOL, took me three reads of your post to understand what you're saying.

Correct me if I got these wrong:
IGH = Internal Gear Hub
IG = Internal Gear
Cogs = the gears on the outside of a 6 speed Brompton
13t & 15t = the two cogs on the outside that have 13 and 15 teeth?

fietsbob
04-13-12, 11:21 AM
Yea, IT people are handicapped by mechanic's acronyms..

IT jargon goes over old mechanic's heads too.

Barrakulyan
04-16-12, 10:14 AM
The LBS told me this:
Right shifter = don't pedal while changing gears
Left shifter = pedal while changing gears

I test drove the 6 speed this weekend and I was shifting while pedling, both shifters. I would start off in first, shift to second (left side) than for third I would shift the left side back and quickly after i would shift the right side. I did that all while pedaling softly, is that bad? I guess I can hurt the gear hub that way or as long as I pedal softly it'll be ok?

Lao
04-16-12, 12:50 PM
My Local bike dealer said that there would be no problem if you pedal softly so I trust him on that. :)

jur
04-16-12, 05:36 PM
If I could make an entirely alternative suggestion...

Use the derailer for shifting between 2 modes - low mode for doing uphills and stiff headwinds, and high gear for regular cruising and downhills. The hub gears are the used for selecting the right gear for the speed you're doing.

The only slight drawback is that the gears might be spaced too far apart but unless you are riding in a paceline or are very tired, this should not really be a significant enough problem.

Ozonation
04-18-12, 08:27 AM
I test drove the 6 speed this weekend and I was shifting while pedling, both shifters. I would start off in first, shift to second (left side) than for third I would shift the left side back and quickly after i would shift the right side. I did that all while pedaling softly, is that bad? I guess I can hurt the gear hub that way or as long as I pedal softly it'll be ok?

I test drove a 6 speed last weekend and ended up doing this as well. Nothing seemed to go amiss.

fietsbob
04-18-12, 08:51 AM
yea flat lands make things simpler.. but hill climbing needs those technique considerations.

My 6 speed BSR Brompton is 2 internal gear-sets ,
the Schlumpf Swiss mountain drive crank adds a big drop 150% reduction gear,
so the hub low is followed by hub high, but in low range,
crank arm turns faster than the Chain-ring.. as if a 50-20t double.

2_i
04-18-12, 11:26 AM
The left 2-position shifter changes gear ratio by about half as much as the right 3-position shifter. In addition, throwing the lever to the outside shifts you to a lower gear. These 2 rules dictate how you should shift in every situation and the resulting order of gear ratios is such as listed by Lao.