Prototype 20" Brompton

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Kell

Veteran
Mine is about 9kg SL3 from 2005. A P-line is 10kg nowadays

In fairness, yours is a SuperLight.

It's lighter than my carbon roadbike.

Pricewise it compares to the P-line - but that has Titanium forks and triangle - making it essentially a modern-day SL.

But I don't think it should be being compared to that as it's essentially the intro model. So specwise, it compares more to the C-Line.

No doubt there will be GT line at some point, if demand is there.
 
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OP
OP
Origamist

Origamist

Legendary Member
About time! It was 19 months ago when I started this thread...and so it came to pass.

For me, the most important aspect will be the ride characteristics - fold is secondary. From what I've heard, it handles very well (not noodley, you can ride out of the saddle comfortably and the voluminous tyres absorb road imperfections), I like the stem/seatpost combos, and I'm a sucker for orange. I'm also a fan of discs on folding bikes, and the Alfine IGH is a sound compromise with a solid range (a belt option would have been nice, but the G Line is already a transformational shift for Brompton and that would have been asking too much!). I like the fork and stem bosses, thru axles, tubeless option and whilst an aluminum fork is never going to set the heart racing, it makes sense. It also has a weight limit of 130kg which is handy for larger riders. The only real downer is the weight, but I suspect this will not be the first choice Brompton model for multi-modal users in busy cities. It also won't be long before modders shave off a few kgs and experiment with drivetrain options. The cost is where I expected it to be and even with a £2K+ price tag, I expect this Brompton to do well.

Unfortunately for me, the staff list is not currently available and I'll have to wait. Which is probably a good thing as 3 Bromptons might push me towards a Decree Nisi.
 
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Kell

Veteran
There’s a couple of things I cannot work out.

The reach and stack dimensions seem way off to me.

IMG_6989.jpeg



Just measured my bike to see how it measures up.

My reach is 680mm and the stack height is 970mm.

Confused.
 

wafter

I like steel bikes and I cannot lie..
Location
Oxford
There’s a couple of things I cannot work out.

The reach and stack dimensions seem way off to me.

View attachment 745938


Just measured my bike to see how it measures up.

My reach is 680mm and the stack height is 970mm.

Confused.


I guess it doesn't help that it doesn't explicitly state where these values are to. Typically (as I'm sure you're aware) R&S are usually given for the frame to the top centre of the head tube; which isn't really relevant here.. while few give effective values to contact points (which is what I assume these are).

For comparison the R&S values as measured for my medium-ish Fuji Tourer to the bars (as clamped by the stem rather than the tops or drops) are 458 and 675mm respectively; so Brompton's figures don't seem too outlandish. Perhaps a bit long-of-reach for such an upright bike but then I have quite a short reach and usually have to fit shorter stems for best fit.

Still haven't meansured the R&S for my Brompton but am not really too enthusiastic about the bike currently as it's still in the dog house for its ongoing issues..

Are you sure you're measuring reach and stack correctly? For the stack it sounds like you might have forgotten to subtract the distance between the BB and the floor... ;)


On the up-side it's good that Brompton are publishing this data and it's heartening to see an apparently "user serviceable" hinge pin in the frame which I hope might trickle down to the C-Line in time... although of course that won't be of any use to the lashup on existing bikes.
 

Kell

Veteran
I was going by the lines they give next to their measurements.

IMG_6990.png



In the past the measurements Brompton gave for the older bikes like mine was from bars to floor, so either they’ve changed the way they display these and forgotten to update the diagram or something else is awry.

ohc=P2EWvDQBYrcQ7kNvgFkY2wt&_nc_ht=scontent-lhr8-1.jpg


The reach I went from bang on the middle of my seat post to the middle of the handlebar clamp.
 
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wafter

I like steel bikes and I cannot lie..
Location
Oxford
I was going by the lines next to measurements.

View attachment 745967


In the past the measurements Brompton gave for the older bikes like mine was from bars to floor, so either they’ve changed the way they display these and forgotten to update the diagram or something else is awry.

The reach I went from bang on the middle of my seat post to the middle of the handlebar clamp.

Ahh yes; I think the issue here is connected with that diagram being total bollocks.

As I'm sure you're aware reach and stack are usually defined at being measured from the crank centre; which from the numbers seems to be what Brompton are quoting in this instance - despite the diagram.

Of course the saddle position is the final piece of the puzzle; although notoriously difficult to measure accurately as there's not obvious single point to measure to.

Looking at them again it does seem that the whole range is somewhat on the large side; with the small being larger than my (medium-large) tourer.

This has piqued my interest now; maybe when I get home I'll measure the C-Line for comparison.
 

Fastpedaller

Über Member
It seems (from 2 notes previous) the hinge pins may be owner-replaceable. I wonder what that means? If only the hinge pin wears I can understand the logic, but if any part of the frame (or any bushes therein) wears, it's still a case of fitting and reaming otherwise it's only 'half a job'
 
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rualexander

Legendary Member
I've noticed that the front forks only seem to have cage mounts on the drive side on all the bikes in the newly released photos and videos, not on the non-drive side.
Seems a bit odd.
 

T4tomo

Legendary Member
I've noticed that the front forks only seem to have cage mounts on the drive side on all the bikes in the newly released photos and videos, not on the non-drive side.
Seems a bit odd.

think about how it folds and come back to us.... :laugh:
 

a.twiddler

Veteran
With Halfords being a dealer. there is at least a chance that we plebs out in the provinces might get a chance to look at one, if not sit on one, and put an end to all the frothing going on amongst the aficionados. Assuming that the average Halfords branch has something like as much knowledge about the G line as they have about the traditional Brommie. It'll be a while before there will be enough on the used market for the price to be accessible to oiks like me, if ever. The original Brommie serves a distinct purpose which makes it worth the premium to at least buy one used, and maybe be impressed enough to splurge on a new one in the future. In its case, the catch phrase "it's all about the fold" is meaningful, as it's pretty well unique. It has compromises, but they are outweighed by the convenience. I hope that Brompton have done their homework. We aren't going to get trains with bigger luggage compartments, for example, any time soon. Maybe it really is for a different market.
 

rualexander

Legendary Member
think about how it folds and come back to us.... :laugh:

I've thought about how it folds thanks.
Think about what you're saying before commenting.

Doesn't preclude having mounts on the non-drive side does it?
Cages may have to be removed but not necessarily the clip on style that use small attachment points such as Gorilla Cage, Fidlock, Ortlieb Fork Pack, Rhinowalk fork bag, etc.
And better to have the mounts with the option to remove a cage when folding than not to have the mounts at all.
 

wafter

I like steel bikes and I cannot lie..
Location
Oxford
It seems (from 2 notes previous) the hinge pins may be owner-replaceable. I wonder what that means? If only the hinge pin wears I can understand the logic, but if any part of the frame (or any bushes therein) wears, it's still a case of fitting and reaming otherwise it's only 'half a job'

Fair point; one would hope they've taken a similar route to the setup on the T-Line - i.e. a shoulder bolt with flanged bushes; all of which should come out with basic tools and not a lot of effort. Unlike the lashup on the current 16" steel bikes.
 

T4tomo

Legendary Member
Doesn't preclude having mounts on the non-drive side does it?
Cages may have to be removed but not necessarily the clip on style that use small attachment points such as Gorilla Cage, Fidlock, Ortlieb Fork Pack, Rhinowalk fork bag, etc.
And better to have the mounts with the option to remove a cage when folding than not to have the mounts at all.

I think it does, otherwise Brompton would have put them on there

the clearance is pretty tight, it would be ok for the tiny mount holes, but not those clip style cages you list

Brompton clearly though otherwise, it would be a bit of a faff. i.e. remove bag, get allen key out, remove cage. fold.
Sort of defeats the object. You can famously fold up a brommie with the front luggage in place so they would want to maintain that ethos.
 

rualexander

Legendary Member
I think it does, otherwise Brompton would have put them on there

the clearance is pretty tight, it would be ok for the tiny mount holes, but not those clip style cages you list

Brompton clearly though otherwise, it would be a bit of a faff. i.e. remove bag, get allen key out, remove cage. fold.
Sort of defeats the object. You can famously fold up a brommie with the front luggage in place so they would want to maintain that ethos.

I think you're wrong.
I can fit decathlon strap on cage mounts onto my standard Brompton forks non-drive side and use a Gorilla cage or Monkii cage no problem and it folds just fine with the mounts in place.
Obviously I could do the same on the new model but it would have been better if they made it with bosses already there.

Also, it's no big deal to fit or remove a normal bottle cage if you're only folding the bike a couple of times a day at the start or finish of a ride.

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