Prototype 20" Brompton

[Drago]

All the more reason for Brompton to sort out a 20 incher for us big chaps. The OP gives me hope that they're working on it, and I've fingers crossed it doesn't get delayed as priorities shift towards the new premises.

 

[T4tomo]

I don't think the larger wheel Brompton is being developed as "Brommy for fatties". Does is say anywhere that it will have a higher advised max rider weight? It should give a smoother rider at the expense of a larger folded package, a trade off that those who aren't daily commuting on train might opt for.

It should bring with it a slightly less cramped frame, but part of the "genius" of the fold is because the frame size is "as small as you can get away with" however extra 4" on the wheel diameter should make that slightly bigger.

the excessive flexing you mentioned on page 3 can generally be solved with a firmer suspension block, or a jubilee clip around the sus block.

 

[cheys03]

Loved riding the Giant Halfway which used 20” wheels in the early 2000s for the smooth ride and smallish folded package. Like many taller folk I thought that a 20” wheeled Brompton would suit me better than the 16” design. I’ve hoped and hoped for many years so should this reach the market I’d be very, very interested. Especially if the discs come too. It might be perfect.

 

[Drago]

I don't think the larger wheel Brompton is being developed as "Brommy for fatties". Does is say anywhere that it will have a higher advised max rider weight? It should give a smoother rider at the expense of a larger folded package, a trade off that those who aren't daily commuting on train might opt for.

It should bring with it a slightly less cramped frame, but part of the "genius" of the fold is because the frame size is "as small as you can get away with" however extra 4" on the wheel diameter should make that slightly bigger.

the excessive flexing you mentioned on page 3 can generally be solved with a firmer suspension block, or a jubilee clip around the sus block.

It was frame flex buddy. To be fair an 8th of a tonne stamping on a pedal is a tough test for a regular bike.

So you don't think they would alter the frame to account for additional loads? I might just have email them.

 

[berlinonaut]

120kg here, and 192, both measured in just my socks.

That's roughly 625g per cm. To get to 90kg in socks you would have to chop off 48cm of youself. This would leave you at unpleasant 144cm of height, so probably not a realistic plan...

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

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.

I've mentioned in various forums from time to time but unsure if I did it here: For the biggies the Bernds folder is in my eyes a pretty good alternative. It is rated to 140kg and for rider heights of up to 210cm. The ride is great, the quality is awesome, the price is high. It clearly does not fold as small as a Brompton but that's not a big surprise. I like mine very much. When you buy used they are affordable.

https://bernds.de/en/faltrad/

"Brommy for fatties"

If they use this as a marketing claim I'll pay you a beer!

It was frame flex buddy.

That's the issue. The hinge on the main tube of the Brompton flexes under massive load or pedaling power and one can probably not get rid of that. In combination with the somewhat long stem and seat post a Brompton with a heavy rider will possibly always feel somewhat flexy. Possibly the hinges on the T-line improve a little bit on that but not sure if they can eliminate the issue.
A stable folder w/o hinge on the main tube like the Bernds is a different world here - but you pay a price in folded size for that.

 

[Drago]

Thanks for the heads up on the Bernds @berlinonaut

 

[berlinonaut]

Alternatively you could i.e. have a look on the Bike Friday Diamond Lama or the Bike Friday All-Packa. Both feature a diamond frame design that Bike friday sold orignally as "heavy rider upgrade" for the original Pocket Llama. Folding size should be more or less on eyelevel with the Bernds, possibly even a tad smaller.

 

[a.twiddler]

And there was I thinking I was the one who had problems, needing a ladder to get aboard and all!

 

[Drago]

I like the look of the Bernds as the fold is more akin to the Brompton. The one gripe with my current the steed is that horizontal Tern type fold, which I find most unsatisfactory.

Now to find a Bernds in the UK.

 

[berlinonaut]

Now to find a Bernds in the UK.

That could be a challenge. They are a very small scale manufacturer in the south of Germany - in business since the 90ies, but never sold a lot or scaled up. Outside of Germany I suspect it will be hard to find one, even harder as you need the largest framesize (not just "any" Bernds) . If you plan to buy used care to buy a relatively young bike (after around maybe 2007) as there have been a lot of incremental enhancements on the bike and older bikes tend to have their issues.

 

[tinywheels]

it looks interesting, wonder why they never expanded?

 

[berlinonaut]

it looks interesting, wonder why they never expanded?

They are a typical small manufacturer, run by the inventor of the bike, his wife and a couple of employees. Probably they never had the intention to grow massively and also neither the capital nor the abilities I suspect. The bikes have always been in the higher price range, so their market has not been huge anyway. I've visited the company a couple of years ago when I was in the area, I'll look if I find some photos.

 

[Origamist]

All the more reason for Brompton to sort out a 20 incher for us big chaps. The OP gives me hope that they're working on it, and I've fingers crossed it doesn't get delayed as priorities shift towards the new premises.

There's always the Kinetics conversion.

 

[Drago]

They don't do anything to reinforce the frame on the conversion?

 

[Origamist]

They don't do anything to reinforce the frame on the conversion?

No, Ben doesn't like meddling with the Brompton frame fundamentals.