Author Topic: Identifying a Brompton Model from its Frame Number?  (Read 3296 times)

Identifying a Brompton Model from its Frame Number?
« on: 15 May, 2023, 08:22:47 pm »
A friend has handed me an old-ish Brompton to service and refurbish. Lucky me eh?

She got it second hand, and isn't sure about the model. It seems generally in good nick but it does need a few parts replaced (eg all the cables, handlebar grips, mudguards). I'd no idea there was such a variety of different models of Brompton, and it seems that lots of components are unique to certain models. So... we need to be sure of the model before we try to source replacement parts. (Jeeze they're expensive.)

Brompton suggest that all of their bikes have a serial number, ten digits, on a sticker on the seat tube, and a frame number stamped on the plate behind the BB. Now then, there's no sticker on the seat tube, but there is a number stamped as suggested to be the frame number.

That number is 146834.

We think the bike is from 1999 -2000, and may well be a model L3.  Would the frame number confirm that?

Thanks.
 

Re: Identifying a Brompton Model from its Frame Number?
« Reply #1 on: 15 May, 2023, 08:36:28 pm »
I'm not sure that the frame number alone will tell you the bike's vintage.

Re: Identifying a Brompton Model from its Frame Number?
« Reply #2 on: 15 May, 2023, 08:37:56 pm »
The model codes all refer to bolt-on parts so are independent from the frame number.

L3 is mudguards, no rack, 3 speed hub. You should be able to check that visually.

The thing you do need to confirm is that it’s a short wheelbase, which it will be if your age speculation is correct.
https://brilliantbikes.co.uk/content/24-is-my-brompton-a-long-or-short-wheelbase

LittleWheelsandBig

  • Whimsy Rider
Re: Identifying a Brompton Model from its Frame Number?
« Reply #3 on: 15 May, 2023, 10:20:25 pm »
If it is a Sturmey hub, there should be a date code on it and the bike will usually be less than a year younger than the hub. https://www.thebromptonman.com/serial--frame-numbers.html#/ will help you.

Photos will help a lot…
Wheel meet again, don't know where, don't know when...

Tim Hall

  • Victoria is my queen
Re: Identifying a Brompton Model from its Frame Number?
« Reply #4 on: 15 May, 2023, 10:30:24 pm »
Bear in mind the last Brompton refurbishment thread took home based enthusiast cycle mechanicing to a whole new level.  You've got a high bar to aim at.
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

Re: Identifying a Brompton Model from its Frame Number?
« Reply #5 on: 16 May, 2023, 06:12:05 pm »
This would suggest that it's a 2014 bike. (Edit - only it's not, see correction below)

Somewhere I picked up this picture of the way that brake lever designs have changed. Same for some other components, e.g. chainset types. That kind of thing would also give a clue.


Re: Identifying a Brompton Model from its Frame Number?
« Reply #6 on: 16 May, 2023, 06:40:44 pm »
This would suggest that it's a 2014 bike.

Somewhere I picked up this picture of the way that brake lever designs have changed. Same for some other components, e.g. chainset types. That kind of thing would also give a clue.


I fear you are mistaken.
The number mentioned by the o/p is the six digit number stamped onto the frame.
This does not relate to the age of the frame.
What is required is the 10 digit number found on the sticker at the base of the seat tube which, in the case of this bike, is missing.

The sticker on my 2014 model starts off the 10 digit number with 1407******, as you'd expect.
The six digit number stamped into my frame bears no correlation to any of that.

LittleWheelsandBig

  • Whimsy Rider
Re: Identifying a Brompton Model from its Frame Number?
« Reply #7 on: 16 May, 2023, 08:56:34 pm »
Has anybody looked at the link in my previous post that references Brompton frame numbers?
Wheel meet again, don't know where, don't know when...

Re: Identifying a Brompton Model from its Frame Number?
« Reply #8 on: 16 May, 2023, 09:02:30 pm »
Yes.
That would place the o/p's bike between August 97 and December 98.
Ryan (The Brompton Man) is usually pretty good with stuff like that.

Re: Identifying a Brompton Model from its Frame Number?
« Reply #9 on: 16 May, 2023, 10:30:14 pm »
I fear you are mistaken.
Oops, sorry all, teach me to answer in haste, won't it.