Hey Bike Forumites,

I have been eyeing a used Brompton for a while.
It seems like they haven't changed over the years that much.

What changes have happened over the years?
Any innovations or major updates?

2012 and below used a one piece crank arm/chainring:
2013 and up have spider crank; standard 130 bcd chainwheel.
Much easier to play with gearing; cheaper replacement when ring wears out:

I think the nicer brake levers started in 2013, too. '17 brings the Big Changes That Matter: Underbar shifters that don't rattle, new bar shapes that use normal-length clamp-on grips.

​​​​​​​ Innovation here you go.

Perhaps taking the proverbial ??

the uber ultimate brompton inovation was the adiction of rear frame lock.
its a tiny litle clamp that prevents rear triangle to slide down if the bike is lifted(i.e. while upstair or downstair)
so, dont buy a brompton before 2007!

Thanks for the input!

I'm not sure if I should be happy the design is pretty much the same, or a bit dismayed.

I have been looking at 3d printers recently, and 6 months can issue lots of innovations... much less 12 years. Urp.

Buy and read the Brompton Bicycle ? https://www.amazon.com/Brompton-Bicy.../dp/1901464253



Author gives a History (1st editition did too )

And they are retro-fit-able so this
only applies if you have no mechanical abilities , but even then your Brompton Dealer, will fix that.

or any bike shop mechanic as I have done,* if you bring in the parts ( you still have to buy them through, the dealer)

I had a Mk 2, 3 speed from the mid 90's I did work on it , such as the catch, then resold it, improved, when I got another used, newer, one..





....

The 1980's production bikes switched from the 1970's prototypes' Le Petit Bi style handlebars to the Dahon-patented 45º folding handlepost.

For the innocent eye nothing really changed. At a closer look almost every component has been changed over time at least once and details and parts have been enhanced massively over time. In any given year smaller enhancements have been made, every ~4 years bigger changes were made. Almost everything is retrofittable, but part costs sum up and some things are expensive. So in general a relatively young bike is the best deal, depending a bit from your budget and needs. Retrofitting a cheaper, older bike to today's standards comes out more expensive than buying a newer one (and sometimes more expensive than buying a new one). Prices for used bikes tend to fall more intensively in the first couple of years and at some point do not fall any further relevantly.

A very rough overview from memory about the more obvious changes (only a fraction of the overall changes):

2000 MK3 -> higher quality parts all over the bike in comparison to the MK2, new folding hinge on the stem, dual pivot brake on the front
2001 SRAM hubs instead of Sturmey, no more 5-Speed
2002 6-speed invented (with 2-speed derailleur)
2004 MK4 with longer wheelbase and new folding hinge
2005 S- and P-models invented, ti-models invented, SON dynamo invented, 2-speed invented. Sturmey SRF3 replaces SRAM 3 speed
2007 dual pivot brake on the rear
2008 rear frame clip as a standard, jagwire cables
2009 6-speed BRW replaces 6-speed SRAM, new saddle, pentaclip as a standard, right aluminum pedal, change of colors from gloss to mate
2010 Shimano hub dynamo replaces bottle dynamo option, aluminum seat post instead of ti one
2012 H-model, LED light on the front, no more aluminium seat post, only steel
2013 new brake levers, new rims, new spider crankset
2015 start of the black edition
2016 new rear carrier, new roller wheels, start of the nickel edition and various special editions
2017 new stems for M and H along with new bars and new under-bar-shifters
2018 new brakes, Brompton electric
2019 new hub dynamo (SP SV8 replaces Shimano and SON)

Along with those go yearly changes in available colors, a lot of smaller technical changes and a lot of changes in accessories like bags etc..

If you can afford it I would go for a 2013 or newer bike. If you can't and want a six speed I'd go for no older than 2009 (BWR). I would not buy a MK2 because of the old frame and outdated, lower quality components. I would not buy a MK3 because of the old frame, at least nor as a daily driver and if it was are not massively cheaper than the usual offers for Bromtons of that age. If you know what you are doing you could buy any MK4 but you should have in mind that - depending from the usage before - a lot of maintenance may occur like rims, rear hinge, chain + sprocket, tires, cables, etc.. This, together with desirable upgrades like i.e. the 2013 brake levers or the pentaclip, may quickly rush you into a price region that you can buy a newer bike instead. Thus I personally would not buy older than late 2008 with the exception of a ti or a cheap offer that is technically in above average condition. In this case calculate a reasonable amount for mainainance and upgrades (~150-200$) and rethink if it's still worth it.

Brompton recommends some aluminum parts (bars, cranks, brake calipers?) be replaced every ~5000 miles:

"...we recommend aluminium parts, particularly safety critical components, are replaced within 5000 miles - sooner for vigorous riders, and especially after an accident or significant impact."

AFAIK this recommendation is unique among bicycle manufacturers. Over on the Classic & Vintage forum you'll find cats riding with decades old aluminum parts. Anyway, if this gives you pause when considering a used Brompton, particularly one with an undocumented history, you can factor in component replacement costs into the sales price.

In opposite - the request to exchange aluminium parts on bicycles on regular basis is normal, common and basically industry standard (and justified due to the aging of the material and the resulting risk of breakage). If people really do it is a different story.

If you are already shocked by that you may want to avoid looking into the manual of the birdy (maintenance section) - there it get's really expensive...

My 2013 S6L-X still has most of it's original alu parts; handle bar, cranks, rear rim, frame clamps, hubs, etc.
I probably did 5K miles the 1st year I owned it. Front rim's braking surface wore out; replaced spokes and
rim - still on same hub. Flown to over a dozen countries/cities, many charity events(some up to 100 miles),
light off road excursions.

100 Miles(160 Km.) on a Brompton by 1nterceptor, on Flickr

Hmph! I have owner's manuals from Trek, Specalized and Giant that don't mention this. Could you help us out with some links?

I would look at optimization theory in general. When you are far from optimum, changes in moving towards an optimum can be dramatic. When you are close to optimum, progress is hard and does not seem to be substantial. In this sense, from the changes you can see where Brompton is with respect to the optimization. But you can read it of course as you want

Last major change was made 15 years ago (MK4 frame, 2004)

Everything else is just incremental part upgrade (brake change, lever change, dynamo change... etc) that can be done yourself easily.

I recommend to get any MK4 frame (avoid bent or rusted ones of course) and put quality parts yourself.



12 years can bring quite a bit of innovation. Back in 2003 dura-ace 7700 was the latest and greatest. MTB bikes had rim brake and 26 inch wheels.

Now we have wireless electric shifter, sub-600gr mainstream crankset, affordable carbon clincher rims, road hydraulic brake, 10-51T cassette etc...

I recently saw that nowadays a full carbon roadbike with Shimano Claris STI lever can cost less than $500. That's some serious innovation IMO.


About 3D printers, personally I own a Form 2 and Ultimaker 2+ but it seems both of them are already surpassed by new affordable ones.

The most significant change is the price.

Factory had to get bigger,, Founder / inventor got to retire.. turned over operations to a younger guy...

All components, except rubber.. have a warranted 12 months .. from those individual manufacturers , that can be sorted out thru the dealer you bought the bike from..

Only the frame itself is covered longer for the original owner..

New stem for the 2019 model.

Classic Italian Quill stems like Cinelli 1A, use the conic expander type , shown on the right .. ..

This is a little old but I had a question since you seemed so knowledgeable about it all - aside from the *stem* on the M-bar, has the shape of the bars themselves (and the curve/dimensions of the inner space) changed over the years?