Calling Brompton riders

General cycling advice ( NOT technical ! )
mick skinner
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Calling Brompton riders

Postby mick skinner » 29 Sep 2015, 8:26pm

How many Brompton riders look at this forum? I want to buy a Brompton and I want information and advice from people who have got one.

My first question is; How many gears have you got on your Brompton, and do you like the gearing or would you prefer a machine with a different number of gears?

Ideally I'd like a one speed Brompton for the simplicity but I'm not hard enough to be grinding up hills in the same gear; two gears seem optimal but when I'm on the flat it can get a bit annoying when I haven't got a big enough gear and I'm spinning too fast; I'm not keen on the six speed because it seems too complicated especially after seeing this video https://youtu.be/Lgfd9Gt_LGk rather ironically called EASY REMOVAL/INSTALL OF A BROMPTON REAR WHEEL.

townbikemark
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Re: Calling Brompton riders

Postby townbikemark » 29 Sep 2015, 8:59pm

I have an M3L - so, 3 speed. I would prefer more gears - it's the first bike I've had to get out of the saddle to pedal uphill...

When I have the cash I'm going to look at some of the Kinetics conversions - he does SA8, Alfine 8 & 11 and Rohloff - he claims they're simple to fit...personally I'd rather buy one complete...
stereotype nonconformance...unpigeonholable...

http://townbikemark.blogspot.co.uk/

alicat
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Re: Calling Brompton riders

Postby alicat » 29 Sep 2015, 9:08pm

I've got a P6R with the gearing reduced. Very glad I have six gears. When the rear derailleur stopped working a while ago I missed the other three gears.

LWaB
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Re: Calling Brompton riders

Postby LWaB » 29 Sep 2015, 9:23pm

6 speed standard gearing. I use the top 4 gears most days I ride it. The bottom 2 gears are nice on the very steep stuff. Every Brompton has a chain tensioner, so there is little effective difference when removing the rear wheel, regardless of the number of gears.

Brucey
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Re: Calling Brompton riders

Postby Brucey » 29 Sep 2015, 10:56pm

Not a current owner but have ridden and worked on Bromptons enough to have a view: I agree with the comment above; the chain tensioner makes it a bit of a faff getting the wheel in and out whatever gearing you have.

Provided you can cope with the two-trigger shifting (and most people do) then (of the current models) the 6s one is the one to go for IMHO. [If looking at used machines, I'd have to say I have a soft spot for the 5s models but then again I am in the happy position that I can probably fix the hub when it goes wrong...others may have a different view....]

One speed and two speed gearing is OK if you don't ride far and it is fairly flat. For any serious distance, or hills, gears just make everything easier. The 6s system is a half-step system, so the very widely spaced BWR gearing is improved with both a wider range and intermediate gears.

Standard gearing is 50T chainring, 16, 13T sprockets on a BWR hub. This gives nominal gears of;

16T: 32.0", 50.2", 78.7"
13T: 39.4", 61.8", 96.9"

-which seems pretty good to me, but you do have choices of higher or lower gearing I believe.

[FWIW the old 5s models could have (say) 50/14 gearing giving 38.3", 45.3", 57.4", 72.7", 86.1", giving gears that are both a smaller range and wider spaced than the 6s models. 50/15 might be better, giving 35.7", 42.3", 53.6", 67.9", 80.4", but you do lose the high gear that way. ]

If you are thinking about an 8s hub or similar, I'm not sure it is really an improvement in terms of rear wheel removal. The reason I say this is that the cassette joint is basically a PITA to deal with at the best of times and on a Brompton it is slightly worse than normal.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

mick skinner
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Re: Calling Brompton riders

Postby mick skinner » 30 Sep 2015, 2:56am

Brucey wrote:
Standard gearing is 50T chainring, 16, 13T sprockets on a BWR hub. This gives nominal gears of;

16T: 32.0", 50.2", 78.7"
13T: 39.4", 61.8", 96.9"


Now that's confusing because this website http://www.bromleybike.co.uk/images/pro ... 0copyd.jpg has a gear chart that says the gears are different from that. Maybe I'm just being a bit pedantic.

Merry_Wanderer
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Re: Calling Brompton riders

Postby Merry_Wanderer » 30 Sep 2015, 6:24am

The Brompton website has (or certainly had recently) a part of the brochure which showed a table of gear inches for each model. I have an M model 6 speed with a 44 tooth chainring. Bottom gear is 29 inches from memory. I don't find the 2 triggers for gearing any more complicated than STI's or driving a car and using a clutch and gearstick :-)

Brucey
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Re: Calling Brompton riders

Postby Brucey » 30 Sep 2015, 8:30am

mick skinner wrote:
Brucey wrote:
Standard gearing is 50T chainring, 16, 13T sprockets on a BWR hub. This gives nominal gears of;

16T: 32.0", 50.2", 78.7"
13T: 39.4", 61.8", 96.9"


Now that's confusing because this website http://www.bromleybike.co.uk/images/pro ... 0copyd.jpg has a gear chart that says the gears are different from that. Maybe I'm just being a bit pedantic.


I've seen several Brompton-specific gear calculators that give similar (peculiar?) results. AFAICT these calculators (for some reason) use a wheel diameter that is slightly larger than 16". Last time I checked, Brompton tyres were still 1-3/8" (although there are fitments which are not) so the nominal wheel size is still 16".

A 'sanity check' is that the middle gear on the 16T sprocket should be given by

16" x (50/16) = 50"

Which is pretty close to the values I quoted (generated using http://www.sheldonbrown.com/gears/internal.html). To get the values that are seen in the other links, (which would suggest that the same gear is about 51.75", and the wheel diameter is about 16.5") you would perhaps need to use ~38mm tyres or something, which is fair enough if that is what you intend to do, but is otherwise a little bit misleading.

If you subscribe to the 'conspiracy' (rather than cock-up) theory, it could be that if invited to compare 'the same gear' on another bike, the Brompton doesn't feel too bad, because the gear is actually smaller than they claim.

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

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simonineaston
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Re: Calling Brompton riders

Postby simonineaston » 30 Sep 2015, 11:58am

Had a six M, didn't like it. Now have a 2 S, which does the business for me - luv it.
Last edited by simonineaston on 30 Sep 2015, 1:24pm, edited 1 time in total.
ttfn, Simon in Easton
(currently enjoying a Moulton TSR & a nano Brompton...)

SA_SA_SA
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Re: Calling Brompton riders

Postby SA_SA_SA » 30 Sep 2015, 12:19pm

All modern 3/6 speed Bromptons will have a NIG 3 speed hub with the troublesome actuator plate won't they?

Perhaps in future Brompton could ask for their custom Brompton BSR/BWR SA hubs to be updated use the CS-RK3 actuator-plate-free design?
http://forum.ctc.org.uk/viewtopic.php?f=5&t=100387&p=939750&hilit=toggle#p939750

I suppose a person could swap the 3 speed BSR for an old oiled non-NIG AW hub, the 6 speed BWR would need some fettling of double (dished?) sprockets onto said old AW.

Does the lack of actuator plate in the SA8 make an slight point in favour of an SA 8 speed in a Brompton?
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pjclinch
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Re: Calling Brompton riders

Postby pjclinch » 30 Sep 2015, 12:47pm

I have an L3 (in other words, a rather old M3L).

It is of that particular vintage right after Sturmey went bust and they put SRAM hubs in their place (though that finally died earlier this year and there's a current Sturmey in now), and also they had the gubbins in place to retrofit the 6 speed when it came out in what was then a few months in to the future.

So a few months after I bought it I went along to try a 6 with the money in my pocket to buy it, and I came back without buying it. I don't really like the 6 very much, to be honest. While I'm all in favour of more gears, frankly I'd rather pay the weight penalty and have a single hub with everything in, rather than faffing about with the up/down double change on the Brom 6. The derailleur effectively gives you extra "half" gears, so from 1 you go to 1-high (derailleur change), and then to 2 (hub up one, derailleur back down), then to 2-high, and so on. It's not exactly rocket surgery, but each time I've subsequently tried it I've felt it's a bit Meh, and if I wanted more gears I'd get Ben "Kinetics" Cooper to put an 8 in for me (I have a Sturmey 8 on my Moulton TSR, it's okay aside from a very noisy 4th).

But it turns out I don't really want more gears, at least on the Brom. My 3 has the -18% reduction (bigger sprocket and smaller chainwheel), and with that I can get it up anything I need to (around Dundee that's some pretty good hills). Yes, I spin out coming down, or even on gentle downs with a good tailwind, but if I was in a Big Hurry I wouldn't be on the Brom, in all probability. It's got a decent range of gearing (I think the wide range I'd find rather bigger steps than I like, though I've not tried one), it's very easy to use, and there's not much to go worng. When it finally dies then I'm pretty sure I'll get another reduced-ratio 3 (possibly the H rather than the M though, but not S: it's not a Hurrying bike, so I'd prefer to sit up than crouch forwards. The butterfly bars on the P are more contrived than needs be for my purposes). If I lived somewhere less hilly than Dundee I'd quite possibly get the -12% rather than -18%, but even if it was fairly flat I'd get that: I prefer relatively high cadences and find the standard a bit over-geared for my tastes, and as I use it for multi-mode travel it may well end up in towns with hills, if only for a day.

Pete.
Often seen riding a bike around Dundee...

pwa
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Re: Calling Brompton riders

Postby pwa » 30 Sep 2015, 12:55pm

A neighbour of mine has a 3-speed Brompton which he likes, except for the lack of gears. On the mainly fairly gentle hills he rides on he runs out of gears going down and up.

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Graham
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Re: Calling Brompton riders

Postby Graham » 30 Sep 2015, 1:30pm

I have a 1990's 5L which I used back in those days for commuting by train into London/City.
It's nearest modern equivalent would be an S3L, but with 5 gear ratios in the hub.

It has a Sturmey Archer 5-speed hub and a "reduced gearing" smaller chainring ( for spinning along at my normal cadence ).

Chaos on the railway one day enabled me to cycle 30 miles home without too much bother.

That gearing suited me very nicely thanks . . . . . but I haven't used it for years.

mick skinner
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Re: Calling Brompton riders

Postby mick skinner » 30 Sep 2015, 2:14pm

pjclinch wrote:I have an L3 (in other words, a rather old M3L).

It is of that particular vintage right after Sturmey went bust and they put SRAM hubs in their place (though that finally died earlier this year and there's a current Sturmey in now), and also they had the gubbins in place to retrofit the 6 speed when it came out in what was then a few months in to the future.

So a few months after I bought it I went along to try a 6 with the money in my pocket to buy it, and I came back without buying it. I don't really like the 6 very much, to be honest. While I'm all in favour of more gears, frankly I'd rather pay the weight penalty and have a single hub with everything in, rather than faffing about with the up/down double change on the Brom 6. The derailleur effectively gives you extra "half" gears, so from 1 you go to 1-high (derailleur change), and then to 2 (hub up one, derailleur back down), then to 2-high, and so on. It's not exactly rocket surgery, but each time I've subsequently tried it I've felt it's a bit Meh, and if I wanted more gears I'd get Ben "Kinetics" Cooper to put an 8 in for me (I have a Sturmey 8 on my Moulton TSR, it's okay aside from a very noisy 4th).

But it turns out I don't really want more gears, at least on the Brom. My 3 has the -18% reduction (bigger sprocket and smaller chainwheel), and with that I can get it up anything I need to (around Dundee that's some pretty good hills). Yes, I spin out coming down, or even on gentle downs with a good tailwind, but if I was in a Big Hurry I wouldn't be on the Brom, in all probability. It's got a decent range of gearing (I think the wide range I'd find rather bigger steps than I like, though I've not tried one), it's very easy to use, and there's not much to go worng. When it finally dies then I'm pretty sure I'll get another reduced-ratio 3 (possibly the H rather than the M though, but not S: it's not a Hurrying bike, so I'd prefer to sit up than crouch forwards. The butterfly bars on the P are more contrived than needs be for my purposes). If I lived somewhere less hilly than Dundee I'd quite possibly get the -12% rather than -18%, but even if it was fairly flat I'd get that: I prefer relatively high cadences and find the standard a bit over-geared for my tastes, and as I use it for multi-mode travel it may well end up in towns with hills, if only for a day.

Pete.


That's the sort of information I want, V helpful.

've seen several Brompton-specific gear calculators that give similar (peculiar?) results. AFAICT these calculators (for some reason) use a wheel diameter that is slightly larger than 16". Last time I checked, Brompton tyres were still 1-3/8" (although there are fitments which are not) so the nominal wheel size is still 16".


If I didn't have dyscalculia I'd be able to do the maths for myself, I wish I could 'cos it would save a lot of faffing about trying to find out from what other people say.

mick skinner
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Re: Calling Brompton riders

Postby mick skinner » 30 Sep 2015, 2:28pm

I eventually found it on the Brompton homepage, straight from the horses mouth. https://brompton.zendesk.com/hc/en-us/a ... nd-ratios-

Btw, Brucey, I didn't mean to be disparaging about the advice you gave, just having a grumble about my own deficiencies I guess.