garyliu

This 16 speed Brompton was from a S1L,single speed.
Crank is a shimano alfine,which is easy for chain line modifying.
Everything is perfect,include the folding...

Micheal Blue

16 speeds on a Brompton...are you going to do some heavy touring? It seems too many gears for such a bike otherwise.

phillybill

ok... that is making me rethink Bromptons now.

invisiblehand

Cool stuff.

My question is the gear range. I'd think that a lot of your gears are way too low for anything other than hauling cargo.

1lesscar

Wow, this looks intriguing. I would also be interested in knowing more about the gear range as well as how you did this. I'd like some nice low gears to help me tackle some very steep grades in my area. I'd been thinking electric mod, but this may be a better route.

Drdul

I, too, would like to know more about this, particularly the front derailleur and crankset. Which specific derailleur and crankset did you use, and what chainrings? What shifter did you use, and how is the cable routed to the derailleur? It's difficult to tell from the photos how exposed the front derailleur is when the bike is folded -- is there any chance of it being bashed and knocked out of alignment or damaged?

The front derailleur looks like a way to extend the gear range with a 3-speed hub (the regular 3-speed hub, not the BWR) so that shifting can progress through the three gears on the hub before there's a need to shift the derailleur, rather than the kludgy back-and-forth shifting on the stock 6-speed Bromptons.

fietsbob

Did you do the work?

Did you use a skip hole lacing pattern and a standard 28 spoke rim ,
or get a 32 spoke 349 rim?

How was the hub OLD narrowed, or was the frame spread?

a how to on that FD mount fabrication would be especially helpful..
any images of it off the bike, before being fitted?

I think the question above:
could be resolved with a Shlumpf IG crankset, no FD needed
I have their mountain drive a 2.5:1 reduction gear, as if a 50-20t double crank
hub high gear, in low range takes up where low in the hub leaves off,
so there are 6 gears much closer together in the lower range.

but being a planetary.. shift takes place at any time/speed,
beneficial for bogging down on a climb.. double shift to next lower combination.

I've been considering a double chainring on my mountain drive ,
to close up the ratios, a bit, in high range..

vmaniqui

hmmm. quite interesting. nice upgrade though may i ask, how's the gearings ?

vmaniqui

adding schlumpf on your bike is one of the best upgrade you can think of, but this set-up will cost you about $500++.

fietsbob

They are Swiss made .. CHF has been gaining value in comparison
to the troubled U$D, and the Euro, and that does not help the exchange rate.

garyliu

GI is 22 to 90.

Cog:16T,
Chainwheels:52/39T
Nexus 8 gear ratio:0.53-1.61

gringo_gus

and how is it for weight ? Thing of beauty though...

jimbeans

Nice fit for the front derailleur, also curious for details on that (is it a stock clamp size?).

Shifting ok (front derailleur) with such short chainline?

Guess the alfine 11 could give you almost same total gear range but a little more expensive, but OLD mod for rear might be weird.

Dynocoaster 

Fudges custom builds https://www.fudgescyclestore.com/index.php?c=5918

garyliu

If you are touring with a bicycle trailer,you really need a wide range gears.

garyliu

Front derailleur is Micro-shift RD-R52(R42?),you can use any hanging type front derailleur,as Shimano SORA or 105.

For installing front derailleur,it need a adapter,I chose a "lite pro" adapter,which is a folding bike parts supplier in China,this adapter is for Dahon Speed 8,it only costs about USD20.

Crankset is Shimano Alfine,orginal chainring is 45T,I replaced it with Shimano 105,52/39T.

Shifter is Shimano Alivio M430 left。

garyliu

Yes, I did all these by myself.

I used the original Brompton 28 spoke rim,Shimano Nexus 8 has a Dahon 28 spoke version,it is a "Red Band" premium model.

Nexus 8 OLD is 132mm,it would reduce 7-8mm by taking off the screw in dust cover(K),and using a car jack to stretch rear fork to 145mm,after removing car jack the fork will remain 125mm.

garyliu

Front derailleur adjusting is very easy,you may doubt the chainline of Brompton is not standard,would it be easy?but don't forget that chain would not move radially in a internal gear system.

garyliu

About 12kg

invisiblehand

Nice work.

When did the Alfine/Nexus 8 get symmetric flanges?

kamtsa

Hi garyliu, very nice bike and thanks for the info. I contemplating for some time adding to my 6sp S Brompton a second chainring with 'greasy finger' shifting so I can copy that part of your configuration.

Is this the crankset you are using? Does it fit the Brompton frame and pedals with no modification or damage?

https://www.shimano.com/publish/conte...L.-type-..html

https://techdocs.shimano.com/media/te...9830604038.pdf

Anything else I should be aware of before doing this mod?

Thanks,

k.

fietsbob

Hmm, Data sheet says offered cog size.. 16t and larger, having tried a 16t cog
and having it hit the end of the frame tubes.. that the dropout is fitted into
on my Mk3 bike, I reverted to a 15t..

what cog did you use [or did they alter the Mk4 rear section for the 2 speed hub?
a 12/16t combo.

garyliu

Hi K.,

Yes,I am using this Alfine S-500,it is a road/mountain size compatible,and have two spacers for different BB width,so it brings convenient for adjusting chainline.

Gary

garyliu

I am using 16T cog and it is very close to frame.
Stretching frame may change the geometric dimensioning of rear frame,so I can insert a 16T cog.

garyliu

Hi david,

Sorry,I have not enough post(50 post minimum)，so I can't reply your message.
My trigger shifter is Alfine 8 sp,it works good.
I am from China,this bag bought in our C2C website:www.taobao.com ,price is about USD3.0(amazing?)

Gary