# Two speed 'derailleur' on Bromptons



## CharlieB (28 May 2014)

Does anyone know why the derailleur on a Brompton fails in wet conditions? I know I'm not the only one who's noticed this, so it's not just me. It's just really annoying.
Is there a cure?


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## Brommyboy (29 May 2014)

The only time my dérailleur fails is when some muck gets to the bracket that shifts the chain. As it is very near the ground, it does pick up muck in wet conditions. This muck is often between the bracket and the stops screws, preventing a full shift. I have used it in very heavy rain without any other difficulty such as what you are reporting.


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## GrumpyGregry (29 May 2014)

CharlieB said:


> Does anyone know why the derailleur on a Brompton fails in wet conditions? I know I'm not the only one who's noticed this, so it's not just me. It's just really annoying.
> *Is there a cure?*


A proper wide-range hub gear without kludges?


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## CharlieB (29 May 2014)

I should have said - the problem resolves itself once the weather improves!


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## Brommyboy (30 May 2014)

> A proper wide-range hub gear without kludges?



Not with a 110mm drop-out!


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## Brommyboy (30 May 2014)

GrumpyGregry said:


> A proper wide-range hub gear without kludges?



with a 110 mm drop-out?


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## GrumpyGregry (30 May 2014)

Brommyboy said:


> with a 110 mm drop-out?


Rhubarb my Brompton has...

a standard rear triangle

a hub gear

eight speeds
no dérailleur
one shifter
The factory are obsessed with coming up with their own novel, and somewhat Heath Robinson solutions, to improving the breed. That and maintaining backwards compatibility.

Really no reason why they can't offer a factory SA 8 speed other than their own conservatism.


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## Brommyboy (31 May 2014)

What I do not think you realise, GrumpyGregry, is that Brompton developed the 2x3 speed system precisely because SA did not exist! Having lost the use of the SA5, the only other hub gear available to fit the existing frames was the Sachs Torpedo, with modification, on which the 2-speed derailleur was then added. It is only since the acquisition of the SA patents by the current company that the SA hub came back into existence. You now have the SA8 fitted to your Brompton, but I doubt very much that the dropout is still 110mm; more likely it is wider, probably 130mm. I also know of Rohloff 14-speed Bromptons, but, like your Brompton, the dropouts have been modified, so are no longer standard. You should therefore not disparage the marvellous efforts of Brompton to overcome the lack of a multi-geared hub when left bereft by the collapse of the original SA company. Nowadays there is quite a choice of these multi-geared hubs, but mostly they are built with 130 or 135 mm widths and can only be slimmed a bit.


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## GrumpyGregry (31 May 2014)

Brommyboy said:


> What I do not think you realise, GrumpyGregry, is that Brompton developed the 2x3 speed system precisely because SA did not exist! Having lost the use of the SA5, the only other hub gear available to fit the existing frames was the Sachs Torpedo, with modification, on which the 2-speed derailleur was then added. It is only since the acquisition of the SA patents by the current company that the SA hub came back into existence. You now have the SA8 fitted to your Brompton, but I doubt very much that the dropout is still 110mm; more likely it is wider, probably 130mm. I also know of Rohloff 14-speed Bromptons, but, like your Brompton, the dropouts have been modified, so are no longer standard. You should therefore not disparage the marvellous efforts of Brompton to overcome the lack of a multi-geared hub when left bereft by the collapse of the original SA company. Nowadays there is quite a choice of these multi-geared hubs, but mostly they are built with 130 or 135 mm widths and can only be slimmed a bit.


Brommyboy don't let your love for the worlds best folding bike cloud your judgement. I know full well the genesis of the shite six-speed only works in the dry solution. That was then. this is now.

My rear triangle remains unchanged from new. Nothing on my bike has been modified. I had the singlespeed wheel in the drop outs last week! No flexing the triangle no changing the drop-outs. 

And I'll disparage Brompton as much as I like. 

I'm on my third. I think that buys me a whole heap of entitlement to carp.


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## Brommyboy (2 Jun 2014)

OK, so your SA8 hub was modified to fit the existing drop-out. As a matter of interest, was the axil also shortened, or does it protrude quite far out, especially on the LH side?


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## Blue Hills (2 Jun 2014)

GrumpyGregry said:


> A proper wide-range hub gear without kludges?


Sounds like my Brompton's 5 speed sprinter gear - wide enough for me.

They don't make them any more of course.


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## GrumpyGregry (2 Jun 2014)

Brommyboy said:


> OK, so your SA8 hub was modified to fit the existing drop-out. As a matter of interest, was the axil also shortened, or does it protrude quite far out, especially on the LH side?


Not aware of any axle shortening. Nor of any quite far out axle action. The SA wheelnuts are a bit wider than stock but once on the bike this isn't noticeable. Doesn't affect the fold or usability.

Everyone who does 8 speed SA conversions modifies the hub by swapping the spacers around. Just like Brompton could, but with their buying power they could get it done at the factory.


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## Brommyboy (3 Jun 2014)

I think you may find that the locknut for the LH cone has been removed. Your axil must have been shortened as the normal length is about 30mm longer than for a Brompton. It would protrude on the LH side for about 25mm. Not a problem unless fitting this without an angle grinder. As a matter of interest, how many teeth in sprocket and chain ring? SA used to limit the lowest gearing to a chain ring at least 2x the size of the sprocket. If that still applies, then the lowest gear with the SA8 would be 32", whereas the BWR will come much lower than that.


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## Bromptonphile (15 Jun 2014)

Regardless of the weather, mine will only shift down (i.e. smaller sprocket to larger, which is supposed to be the trickier shift). It won't shift the other way without a nudge from my heel, which is impossible without looking, which of course is dangerous. At the moment, I'm riding it as a somewhat highly-geared three-speed. |||Any advice welcome.


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## Bromptonphile (15 Jun 2014)

User said:


> Get a proper bike?


Huh! Cheek! (OK, I admit that a brommy isn't ideal for all purposes.)


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## Pale Rider (15 Jun 2014)

I believe Brompton reckon their 3X2 system is lighter than a multi-gear hub.


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## Blue Hills (16 Jun 2014)

Bromptonphile said:


> Huh! Cheek! (OK, I admit that a brommy isn't ideal for all purposes.)


Don't be so defensive.

On balance mine is possibly my most versatle bike.


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## TheDoctor (16 Jun 2014)

Pale Rider said:


> I believe Brompton reckon their 3X2 system is lighter than a multi-gear hub.


Over a kilo lighter. I can live with a slightly awkward shift pattern for that.


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## Pale Rider (16 Jun 2014)

TheDoctor said:


> Over a kilo lighter. I can live with a slightly awkward shift pattern for that.



Sounds a lot, but I have an Alfine 11 hub on a 29er bike and you can feel a lot of weight in the back wheel.


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## Bromptonphile (16 Jun 2014)

Blue Hills said:


> Don't be so defensive.
> 
> On balance mine is possibly my most versatle bike.


I think it's a good idea to have a "proper" bike as well as a Brompton (or any small-wheeled folder), for heavy-duty touring, rough ground, etc., but Bromptons are great for what they're good at - city commuting, and lightly-laden, on-road day-rides and tours. My avatar, btw, shows my Brompton at the start of a week-long, heavily-laden, self-sufficient tour of the West Country some years ago. That was when I discovered the hard way that they are not really cut out for that kind of thing.


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## GrumpyGregry (16 Jun 2014)

TheDoctor said:


> Over a kilo lighter. I can live with a slightly awkward shift pattern for that.


I don't notice the extra weight.


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## GrumpyGregry (16 Jun 2014)

Blue Hills said:


> Don't be so defensive.
> 
> On balance mine is possibly my most versatle bike.


I flip and flop between Brommie and a disc braked tourer with fat tyres being the most versatile tbh.


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## Crankarm (16 Jun 2014)

I never had any problems with the deraillieur shift on my Brompton L6 or hub. No more problems than you would get with a deraillieur specced road or mountain bike. Yeah if you ride it for a week in pouring rain then yes the change might get a bit difficult because all lube is washed off the chain making it very noisy and the crud and grime builds up, but what deraillieur system wouldn't suffer the same? Just needs cleaning and re-lubing then all fine again. The IHG is fine.


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