Prototype 20" Brompton

[Kell]

We know all of the info required to work out the gearing (chainring size, hub ratios, tyre size) with the exception of the rear sprocket count.. perhaps some detective work from pics could give an educated guess

You might know it. I just have it. I haven't a clue how to compare one with the other.

😕

 

[T4tomo]

Thanks for that. I'm sure that at some point they'll releases the figures and how they compare based on using OEM Brompton parts.

From memory (and bearing in mind I was on the flat and not going particularly hard as it was Covent Garden and there were thousands of tourists) I was in sort of 4th/5th ish.

I meant to start my watch so I could track it on Strava, but forgot.

This one has been updated for the G linealready

- choice of chainring is usual with brompton, Alfine 8 I think only uses 18T or 20T sprocket

http://www.xldev.co.uk/tools/bgc.aspx

 

[wafter]

You might know it. I just have it. I haven't a clue how to compare one with the other.

😕

I'm happy to the calcs with the right info; however it looks like @T4tomo has beaten me to it

 

[Kell]

Assuming the above calculator is correct.

This is how the 8-speed stacks up against the other options.

I recreated the chart to try and make it a fair comparison as the original one used different chainring sizes throughout. I've based this on a 50T Chainring for no reason other than that is I think the ‘standard’ one.

Also included my own bike at the bottom which is running a Spa Cycles 48 tooth.

 

[Kell]

Depending on which of those calculations are correct, the ones that would suit me best would be either the 50T combined with an 18T sprocket or a 54t with a 20t sprocket. Neither of which would have the ultimate top end, but both would give me a slightly easier pedal up my horrendous hill.

So I'm not really sure if offers me enough to consider the switch. Although I would concede that my most used gears are 4/5 and then probably 3. But I often find myself thinking 4 is too low and 5 is too tall, so I could probably find myself with a better choice.

I almost bought a 12-speed P-line a few months back and was then pleased I didn't when I heard about the G-Line being confirmed.

Looking at the stats above I think the 12-speed would suit me better. Especially as it looks like I'd be in the middle ring more often, and therefore it would be more efficient.

Kind of confused now. It could be that a G-line would replace both my current Brompton and my 25 year old MTB - if I can get a test ride of the medium and it suits me. But realistically, the 12-speed is lighter and more suited to my current commute.

Definitely going to hold off until the modders get involved and look at it again in the future.

 

[Kell]

That's a real miss by Brompton not even having a medium (I would guess the most likely popular size) available for test rides or even just to play around with in store.

I wouldn’t swear to it, but I think I overheard one of the guys say to another that they’d sent the medium back as it was damaged in transit.

As my bike doesn’t have standard height bars. I guess going to another off-the-shelf Brompton is always going to feel weird to me.

On my original test rides of the standard Brompton is 2015, I felt the M type was too high and the S type too low for me. So I worked out how to get mine to be somewhere in between.

With that in mind, it may not be possible for me to do it with the the new G-line. Or even a P line if I went with a standard Brompton.

 

[Kell]

Nice work - although it seems their idea of reach is still at odds with the generally accepted definition of measuring from the crank centre..

Perhaps they're watching this thread... in which case: Sort your facking C-Line hinges out!

As if by magic...

Site's been updated.

 

[Gunk]

Can you mix and match or is it pretty prescriptive

 

[Kell]

No idea - not tried to configure one yet.

I still need to try and get a sit on one of the mediums.

Looking at that info, it seems like the stack height would be better suited to me, but then I worry that the reach won't be long enough.

I'd like to try any of them with the seat pushed back though.

 

[Gunk]

They’re a bit rich for my tastes, I’d rather put the same money into a nice 753c with Super Record

 

[wafter]

As if by magic...

Site's been updated.

View attachment 748360

lol - nice to see they've sorted that; looks like we've found a hidden back-channel into the brain of Brompton

 

[Twizit]

No idea - not tried to configure one yet.

I still need to try and get a sit on one of the mediums.

Looking at that info, it seems like the stack height would be better suited to me, but then I worry that the reach won't be long enough.

I'd like to try any of them with the seat pushed back though.

I bit the bullet and was likely one of the first to pick up my new model at just after 9am this morning - lucked into the first batch at my local dealer.

Haven't had a proper chance to play with it yet but did note that as set up the bars are angled so that the rise is towards the rider and upwards, making for a more sit up and beg position (although I'm used to an S type std Brompton and drop bars on all my other bikes). I suspect there's a lot of playing around with the bar angle and seat position that I can do to create a slightly more spacious and less upright riding position. That and obviously the option to change out bars if you really wanted.

Will report back here as and when I get chance to properly put it through its paces. First up will be sorting the tyres into tubeless set up, and getting the rising position just so.

 

[Fastpedaller]

I suspect there's a lot of playing around with the bar angle and seat position that I can do to create a slightly more spacious and less upright riding position. That and obviously the option to change out bars if you really wanted.

I'm guessing from the mention of 'bar angle' that the bars can be rotated on the stem?

 

[Tenkaykev]

I had the email and took a look. I see the new electric 20" model now has a rear powered hub.

 

[Twizit]

I'm guessing from the mention of 'bar angle' that the bars can be rotated on the stem?

Indeed, I've only had a quick look but it seems a std 4 bolt clamp, albeit at the top of the handlebar post rather than the end of a stem.