Brompton design changes over the last 10 years
 

I may well try to get hold of a second-hand brompton in the near future and I'm wondering how to value Bromptons based on their year, i.e. assuming they're mechanically in good working order were there any landmark years when significant improvements were made?

They shifted to the long wheelbase version early in the last decade. The variations in stems and handlebars occurred a few years ago.

How much of a change was made to the wheelbase? Did that involve making the fold slightly larger?

Nope, adds 20mm but not said to add to folded length,

the head tube, portion folds back,after all.
they also changed how the hinges were made, from a Hot forged piece, to a cast piece.
butt brazing , replaced by a capillary brazing join between hinge and tube.

the newer rear portion adds braze fittings to mount the external 2 speed shifter.

I have a Mk2 bike with AW3 hub. might sell it and get a newer one ..

An extra 20mm to the wheel base isn't a huge difference.
Has the rear triangle spacing always been the same? What's the required OLD?

I just found this on a website, thought I'd stick it here for reference:

The Brompton timeline

2010
Brompton receives the Queens award for international trade and Queens award for innovation

2009
Andrew Ritchie receives the Prince Phillip designers prize
Brompton Wide Range Hub (BWR) introduced - with a 302% range
Satin finish introduced across the whole range

2007
Rear frame clip introduced

2005
S-type (sports / straight) and P Type handlebars introduced
Superlight upgrade launched - including alloy headset, titanium forks, rear frame, pedal bolt and mudguard stays.

2004
Long wheelbase and improved hinge joints introduced

2002
Brompton 2 sprocket derailleur system introduced

2000
Mark 3 models introduced - better componentry all round

1995
Brompton receives Queens award for export

1987
Brompton goes into full time production

1981
First 30 Brompton bikes produced to order

1976
Brompton Bicycle is registered as a limited company

1975
Andrew Ritchie begins designing a folding bike in his flat, overlooking the Brompton Oratory

What's the 2007 change that's referred to here, "Rear frame clip introduced"?

clips the rear frame to the main frame so the rear frame does not drop when lifting the bike.

Aha. Interesting, I didn't realize that aspect of the design had been changed. I guess it might have been a problem when e.g. lifting the bike up a small flight of stairs. . . or perhaps not really.

Anyone know what year the raw lacquer finish became available?

I am not sure when it was introduced, but it was removed from their catalog in 2009 due to a change on the composition of the main frame tubing and reintroduced in 2011 after a 18+ month hiatus. They changed the type of clear coat and now the Lacquer is back!

improvement!
 

Since 1975 until 2011
1.Is there significant difference in dimension? Wxhxd?
2.Is there significant difference in weight?
3.Folding mechanism?

Now that's improvement!!

Dimensions and folding mechanisms have changed little since the first Bromptons but the weight has dropped considerably, relative costs are similar and durability is much improved. Sounds pretty good to me.

Any idea if weight has changed from mark 3 to current models?

Standard weight hasn't changed significantly but the superlight front wheel, Ti or Al seatpost and other Ti options have dropped weight.

Long live the Raw Lacquer..... it is the best looking finish to my eye.... but then I'm biased, as I own a Raw Lacquer (2009) model :thumb:

I agree, it is the nicest finish by far and I think that mods/component changes tend always to sit well over neutral metal frames. I've just put a Greenspeed Scorcher on my green Brompton and it doesn't exactly look like it belongs.

Wait, what? I'd been told that the Scorcher doesn't fit on the rear wheel because it hits the chainstay brace. Tell us your experience.

On the front. . . and the fit is tight there. I had to bend the whatsitcalled. . . fender stays, a little. Looking at the back wheel I'm not sure if it's possible to fit one. . . I can't measure accurately but I think it's not possible, fender or no fender. Though my Brompton is a mark 3 I think, so perhaps the rear triangle has been altered since then (I don't think it has)? Hmmm, looking at pics they seem to have added cable guidey-bits.

According to a post here:

http://www.velovision.co.uk/forum-ne...hp?3,5040,5701

it is possible, but as someone said in another post on this forum it's the chainstay bridge that doesn't provide enough space. On my bike there's about 5mm gap between Marathon and bridge and I think the scorcher is about 7mm taller/higher than the Marathon.

Looking again I think velovision.co.uk weren't making stuff up, so long as you don't have the axle fully into the dropouts the Scorcher will fit. The problem then may become the tyre rubbing against the bolt that secures the mudguard flap. . . that might have to be taken off. But it looks as though fitting is possible.

i own mk 2,3,4 Bromptons (1992,2002,2010) in terms of designs is just a minor bit here and there improvement, you could get any version and fit the mod later, the oldest obe probably doesnt have a luggage holder, differnt gear box vairation as well 1992-sa hub, 2002 sarm hub 2010 bwr/sa hub. I would recommend you to get the m3l, some of the version has 5 gears on it on the older ones. btw where are you from? the uk? try gumtree and ebay

Keep it. Use it as a spare when you get your newer one. I always do just that with my bikes-especially ones I really like.

Buyer is a friend, in town. have a line on a 2 year old one, L3M, green.
X-fer the MD crank , get a new 15t cog..
they come out of spares for the SRAM Mk 3 hub.
3 teeth are shortened, for shifting to the 13, never noticed their absence.

seller of the green one wants to get a 2 speed..

"2004
Long wheelbase and improved hinge joints introduced"

pre-2003 models wheelbase is 102cm or 40.2"
2004+ models wheelbase is 104.5cm or 41.2"