Prototype 20" Brompton

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Fastpedaller

Senior Member
The difference in bb height as measure is indeed as expected very close to 2 inches, being the difference in rolling radius of the 2 tyre sizes. maybe Brompton will look at a slightly lower BB? One advantage of the larger tyre is the extra ground clearance where more gear/range dictates a longer derailleur/tensioner. With a higher bb, a really large chainring won't drag on the ground either :laugh:
 

berlinonaut

Veteran
Location
Berlin Germany
With a higher bb, a really large chainring won't drag on the ground either :laugh:
Seems not to be a huge problem currently:

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(photo by @chriscross1966 from the Gallery: https://www.cyclechat.net/media/persephone.9817/)
 

tinywheels

Über Member
Location
South of hades
any idea what's going on with the rear hub?
is it electric?
This is an interesting bike.
Judging by the accoutrements on the handlebars he's either got a long commute or possibly just likes the world traveller look.
 

berlinonaut

Veteran
Location
Berlin Germany
It‘s a Rohloff hub at the rear - not a motor

No. It's a motor. You can see the cables go there (coming down the seat stays) while on the other hand there are no shifting cables (which are on the left side of the hub with a Rohloff) and on the bars there is a derailleur shifter on the left but no Rohloff shifter. Also, a Rohloff with disc brakes always has the external shifting box which is lacking here as well.
 
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Drago

Legendary Member
Now this would interest me greatly if it came to market.

When I went carless last year I wanted a folder for train journeys down to my Dad's - ride the 9 miles to Wolverton station, train to Euston, ride across to St Pancras, train to Ashford, ride to my Dad's sorted .

The regular Brompton is just too small for me and with my weight aboard flops and flaps like Larry Grayson's wrist in a semaphore class. It was more like riding a cross trainer than a bicycle. That gave me a serious downer because the fold is just to die for, and the finish is lovely, but most of all that wonderful fold.

On the recommendation of Road.cc I went for the Intercity Disc 9, the highest scoring folder they'd ever tested. Very fast, rock solid flex free platform, very nicely equipped and inexpensive, but...the fold. It folds more in the manner of a Tern, and while it isn't heartbreakingly bad (QR pedals help) its still a faff to carry, even for a longed armed orangutan like me.

So if Brompton brought out a 20", suitably scaled up and strengthened for larger riders I'd not hesitate to give them whatever they wanted for one. Irony is that as I ride the Intercity from Ashford International station out of town to my Dad's place the route takes me past the site of the new Brompton factory. Hopefully they'll look out the window, see me ride last and realise they're missing a nice chunk of market share and do something about it.
 
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ExBrit

Über Member
Now this would interest me greatly if it came to market.

When I went carless last year I wanted a folder for train journeys down to my Dad's - ride the 9 miles to Wolverton station, train to Euston, ride across to St Pancras, train to Ashford, ride to my Dad's sorted .

The regular Brompton is just too small for me and with my weight aboard flops and flaps like Larry Grayson's wrist in a semaphore class. It was more like riding a cross trainer than a bicycle. That gave me a serious downer because the fold is just to die for, and the finish is lovely, but most of all that wonderful fold.

On the recommendation of Road.cc I went for the Intercity Disc 9, the highest scoring folder they'd ever tested. Very fast, rock solid flex free platform, very nicely equipped and inexpensive, but...the fold. It folds more in the manner of a Tern, and while it isn't heartbreakingly bad (QR pedals help) its still a faff to carry, even for a longed armed orangutan like me.

So if Brompton brought out a 20", suitably scaled up and strengthened for larger riders I'd not hesitate to give them whatever they wanted for one. Irony is that as I ride the Intercity from Ashford International station out of town to my Dad's place the route takes me past the site of the new Brompton factory. Hopefully they'll look out the window, see me ride last and realise they're missing a nice chunk of market share and do something about it.

I absolutely agree about a Brompton for chunky monkeys. At 100kg I'm technically over the limit if I wear clothes. Every pothole is a potential disaster. Mind you, I've ridden my Brompton on some pig-awful trails and everything's still working OK. That's a very fine bike they make there.
 
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Kell

Veteran
When I bought mine, i was told they were rated to 130kg and that was really only due to their brakes not being good enough for anything over that.

I've since found that the official line is now 110kg which I would be borderline without luggage, and over it with.
 

Drago

Legendary Member
I'm not so worried about failure as I am about the frame simply not being stiff enough for that load. The way they flop and flex with me aboard is pretty disconcerting, like riding a floppy spring. They're a bit cramped for me too, although I could probably live with that. 20" is something I've been hoping for this last 15 years, and I'm quite excited with the thought thet they're on the case.
 

Drago

Legendary Member
Out of all I tried it was, surprisingly and by quite a way, the Interdity Disc 9 that felt the most solid with my 1/8th of a tonne aboard. And it's a flyer too. Thanks to road.cc for putting me onto it.

But it's got the Tern fold, which is not the best solution :sad:

I need the Brompton fold in my life. I feel emasculated without that marvellous fold.
 

Kell

Veteran
I know it's too late now, but i wouldn't have another Aluminium bike. i've actually never liked the harsh feel of the way they ride, but more so because I snapped two Dahons (one Matrix and one Matrix Lockjaw) in the past (both went on the seat tubes).

I only found out after mine snapped that the max rider plus baggage weight was 90kg. At that time I was probably about 95kg. Never even occurred to me to ask. But it's what prompted me to ask about the Brompton when I was looking at it.
 
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