Prototype 20" Brompton

[wafter]

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.

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

 

[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.