Brompton development over the years

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steelframe
Posts: 42
Joined: 3 Aug 2015, 10:02pm
Location: Berlin

Re: Brompton development over the years

Postby steelframe » 23 Sep 2019, 7:31am

TrevA wrote:I’ve just bought a new Brompton M3L after never having owned one before, so nothing to compare it to. I’m liking it so far but I find it’s a bit over geared. Spend most of my time in 2nd gear, changing down to 1st for rises and drags. I’m not sure I’d be able to climb a substantial hill on it. I’ve hardly used 3rd gear.


I agree that the 3-speed with (59t -> typo, should have been ->) 50t /13t is too long from factory. I'd recommend swapping the 13t sprocket from factory for a 14t, much better. Typically no need to change the chain plus much cheaper (costs barely anything) than changing the 50t chainwheel for a 44t.
Last edited by steelframe on 23 Sep 2019, 8:01pm, edited 1 time in total.

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Mick F
Spambuster
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Joined: 7 Jan 2007, 11:24am
Location: Tamar Valley, Cornwall

Re: Brompton development over the years

Postby Mick F » 23 Sep 2019, 4:50pm

I was in Evans Cycles today in Plymouth.
They had on display an electric assist Brompton. Nearly three grand to buy.
Mick F. Cornwall

SA_SA_SA
Posts: 1850
Joined: 31 Oct 2009, 1:46pm

Re: Brompton development over the years

Postby SA_SA_SA » 23 Sep 2019, 5:40pm

steelframe wrote:.....I agree that the 3-speed with 59t/13t is too long from factory. I'd recommend swapping the 13t sprocket from factory for a 14t, much better....
I have 46t/15t as my idea is that when there is a choice between the following, you lose more time walking up hills than you gain pedaling down instead of freewheeling.
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steelframe
Posts: 42
Joined: 3 Aug 2015, 10:02pm
Location: Berlin

Re: Brompton development over the years

Postby steelframe » 23 Sep 2019, 8:08pm

SA_SA_SA wrote:
steelframe wrote:.....I agree that the 3-speed with 50t/13t is too long from factory. I'd recommend swapping the 13t sprocket from factory for a 14t, much better....
I have 46t/15t as my idea is that when there is a choice between the following, you lose more time walking up hills than you gain pedaling down instead of freewheeling.


You gain a bit on the hills with 46/15 but for my taste this would be far too short in the longest gear. At a cadence of 75 you would spin out already below 25 kph with the longest gear offering just 5,44 metres of development. The stock 2-speed offers ~6m in the highest gear with the stock 54t chainwheel and that seems about right for most people (though I mounted a 60t chainwheel and others prefer a 50t and some even a 44t both of which I would consider to be way too short). A matter of taste. Compare the two here: https://ritzelrechner.de/?GR=SAAW&KB=50 ... 5&UF2=1330

Brucey
Posts: 37433
Joined: 4 Jan 2012, 6:25pm

Re: Brompton development over the years

Postby Brucey » 23 Sep 2019, 8:16pm

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briansnail
Posts: 36
Joined: 1 Sep 2019, 3:07pm

Re: Brompton development over the years

Postby briansnail » 28 Sep 2019, 4:45pm

I have four bikes currentlyparked in my living room.One is a immaculate 15 year old Brompton. Unbeatable for reliability and an icon for British design the world over.
Please do not change this fantastic bike.

briansnail
Posts: 36
Joined: 1 Sep 2019, 3:07pm

Re: Brompton development over the years

Postby briansnail » 29 Sep 2019, 3:51pm

Brompton's are fantastic unbeatable I just run out of words. My problem is I can't leave it anywhere. Its hot literally. All cycle thieves ultimate ambition is to get hold of one. Complaints - Brompton have bought out a brilliant e bike version. I did point out that there was nothing in the rules against. However they firmly block my attempts to enter it in the annual Brompton London race to my dejection. Bet I could have won!