maranen

You are right. I hope that Merc will start selling this version with 13 spokes on Ebay.

maunakea

added to the list: 13 ga. SS spokes

I am very curious to learn from GG the difference between "ancient type alum. alloy tube" and "alum. alloy made by hydraulic pressure", and what F/ and R/ mean in the "Frame" spec .... probably forward of the maintube hinge and rearward of the maintube hinge.

maunakea

GG has a UK distributor, but not a N. Am. one. CMIIW, I think the Mercs in the States have been imported from the UK.

jur

Re 13# spokes:

Sheldon Brown writes that thicker spokes ain't necessarily better. You WANT spokes to be able to flex, so let's go for 14G-15G butted spokes. Lighter but more robust, since the thinner section does the slight stretching under load, leaving the thicker section near the elbow with less stress.

Broken spokes is far more likely to be a crappy built wheel rather than the spokes' fault, unless they were crappy spokes.

maunakea

OK... changed it to "upgraded spokes/wheelbuild" Curious.... broken spokes are rare on the DT Mini... better wheelbuild?

Now to build the IP case. Please contribute. Let's assume we go with the FL frame without "ancient aluminum", i.e., the FL-BP01-x frame.

Part One: What are the most striking "visual" differences between the FL and the C/M/S/P?
1) arch of maintube is noticeably angular in the C/M/S/P; the FL is is smooth arc
2) C/M/S/P all come with the very distinctive "all nose" saddle (granted it can be adjusted, but the standard pix show it "all nose"
3) V brakes on FL vs calipers on C/M/S/P
4) FL has integral, hydraulically extruded headtube/front maintube (I think); C/M/S/P has welded pieces of tubing
5) handlepost hinge is flat on FL and rounded on C/M/S/P; if we can get the Sunzone handlepost/quill, the difference will be even more dramatic, e.g., telescopic.
Added 6) telescopic handlepost allows flatbars, or design other than "longhorn"


Part Two: Technical Differences
1) FL has 3-speed or 7-speed gear hub; C/M/S/P have SS, 2 cog RD, 3-speed gear hub, and 3spGH with a 2 cog RD on some
2) V brakes on FL vs calipers on C/M/S/P
3) FL has integral, hydraulically extruded headtube/front maintube (I think); C/M/S/P has welded pieces of tubing

EvilV

Well - I can't argue with you on engineering principles. All I can say is that Brompton went for 13 gauge spokes from 14 gauge about 17 years ago because of problems with broken spokes on early bikes. This move made further failures less common. My bike has 14 gauge and I've had to replace 7. I can do it in twenty minutes now without any rush. I just peel back the tyre and tape and replace the broken one with the wheel on the bike. Maybe if I don't bother with having a rebuild done, I'll get that down to ten minutes before I've replaced the lot with the thicker ones.




The issue is as I understand it, the sixteen inch wheel with a nice fat three speed hub makes a steep angle at the nipple and at the elbow with quite a bit of sideways pull. Bigger wheels have a lot less apparently. I think I had some variable tension in the wheel at the outset and this allowed flexing which fatigued some of them. I don't know if they are crappy spokes, but the fact that Brompton had the same problems suggests it is a design thing. It is only the back wheel that is affected - the front is original and entirely true. I think it is about power transmission and hammering uphills. I broke two while accelerating hard from rest - heard them 'ping'.

EvilV

Brompton frame is brazed steel, FL is alloy tube. I'd rather have the steel if the price was right. Steel has a better stress life and a more gentle failure mode. I'm not suggesting that you ask GG about steel frames - I doubt they are geared up for that kind of thing. Brazing is pretty specialised. I'm just pointing out the difference.

One thing that might be explored is the handlebar strength. The M type Brompton handlebars in the original 1980s design were prone to snap suddenly after hard use. This caused some very nasty events as you can imagine. Brompton brought out a strengthening cross peice kit to get around this with the bikes they'd sold and also changed the specs of the tubing for future production. Since GG are using OLD Brompton designs, they may have the original weak handlebar spec, like they do the weak rear spokes. This may need watching for those of us who have them. It would be no fun at all to be riding in heavy traffic and find oneself with a chunk of free floating handlebar in one hand.

The shape of the FL bars IS the same as the old Brompton ones, so I expect the tubing is the same too. See Brompton safety notice below -

https://www.bromptonbicycle.co.uk/ind...safetynotices2

maunakea

EvilV, good points ... but on the maintube, "R/hi-ten steel" I think means the maintube aft of the maintube hinge is steel, which I agree, if steel, shouldn't be changed.

I would like the telescopic handlepost to put the handlebar clamp at standard level... no "longhorn bull" effect. The "longhorn" look is very distinctive, and best avoided from a copyright perspective.

EvilV

Yes the rear triangle. handlebar post and front forks on GG bikes are of course steel. The main tube is CERTAINLY NOT (knew it but just checked with magnet). My point is that the Brompton main frame is steel throughout. I'm sure GG would not want to do that they are obviously set up for alloy frames which are probably much cheaper to make. 'R/high ten steel' means the rear triangle. The 'English' on that site is tricky to say the least - incomprehensible in parts.

I think the Brompton handlebar safety notice referenced above needs to be taken into account by the likes of you and I that have Mercs. I'm sure the bars are old design flawed ones. I don't want to be the first Merc rider to break one and end up bouncing down the road on my face followed by a ten ton truck. I'm going to try and buy the B handlebar brace for pre 2000 bikes. I'm sure the dealer will sell me one if I ask.

maunakea

The F/ vs. R/ "frame" spec for the FL bikes divides F from R at the RT/seattube hinge, then, not at the maintube hinge as I previously thought.

maranen

When I got my Merc I decided to replace the original handle-bar with a straight one. I had an idea to make bar-ends from the original handle-bar by cutting it to suitable lengths. First I cut it in half with a tube-cutter. It surprised me that the tube was significantly weaker in the middle – only few turns with the cutter -, where the tube’s outer diameter is a little bigger than elsewhere. I think this is because in the process of “drawing” the tube the same amount of material is used for thicker and thinner areas. I measured the wall thickness in the middle and elsewhere and the difference was about 0.5 mm. I was happy to have taste that prevented me from using the weak handle-bar.

Are you sure that Brompton’s frame is steel, not Cro/Mo?

psykoocycle

I'd be interested, but it will depend on price at the end... always wanted a brommie, even settle for a Merc!

LWaB

The handlebars are bulge-formed (think blowing up a balloon), not drawn.

LWaB

The 'longhorn' bars allow the grips to spread around the front fork and axle. Changing to flat, height-adjustable bars will increase the folded width noticeably.

maunakea

or, since the handlepost will be telescopic, permit a different disposition of the handlebars in folded position.

LWaB

Thus slowing the fold/unfold with an additional action, with the bonus of additional weight and cost and the need to straighten the handlebars when unfolding (depending on keyways). A telescopic stem has to be straight, not curved gently forward like the Brompton, so the fold is wider anyway.

Every 'improvement' comes at a cost, usually both physical and financial, sometimes temporal. Be careful about incorporating too many improvements. You'll end up chipping away at the only advantages of the Brompton - small folded size, reasonable weight, quick fold, reliability.

maunakea

LWaB, good points. The difference in handlebars provides significant copyright differentiation for the standard version, however. Longhorn bars, or even a P-like bar, and a short handlepost could be options.

maranen

Hi
My Merc has a straight handle-bar attached with a bar-adapter. The handle-bar is now about 6cm higher than the lower level of “longhorn” bars. I just checked that the parts that first touch each other when folded are the nut of the front cantilever brake pad and the original handle-bar stem. The folded width did not increase noticeably. It depends on the modification if the width increases.

wubrew

maunakea, I will be trasitting Taiwan in December. Thinking about getting a swivel head or a Merc/Flamingo.
For those who like to see the Flamingo pics here they are







The special clip that prevent the rear wheel from folding when the bike is lifted up.







Cheers

14R 

For the record, if we really have the ability to custom order each and every bike, I really don't want any of the wiring, lights or dynamo stuff.

migjet

Great pics, wubrew! These make it even more interesting to get one! Are these your own bikes?

wubrew

The Brompton is mine. The yellow Flamingo is a sample that David Black at Rad-Innovation has for eval. and possible marketing. That was last year right after the Interbike. I tried it. It's a pretty well built bike with all the characteristics of a similar Brompton. Rather flashy. Long term durabilty, quality? Can't tell.

bookishboy

I'm definitely interested, but any idea how much this would cost total?

maunakea

wubrew, your pix are better than GG's! I love the side-by-side with the Brommie. Could you elaborate on the difference in handling? The ride comparison would be confounded somewhat by the different saddle on the FL, and perhaps by the passage of time.

Your pix show the difference in maintubes quite clearly, esp. the hydroformed shape of the FL maintube.

Has David Black made any progress in adding GG bikes to his lines? www.rad-innovations.com doesn't show any GG bikes.

Concerning the lighting system, I will ask GG to offer it as a kit that a buyer can install. [added to list]

wubrew

I agree. Those FOO-FOO stuff got to go. I believe it all come standard, though. Notice the main frame is more angular and massive. That= more weight?