Hub gear identification

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NickF
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Joined: 16 Oct 2020, 9:45am

Hub gear identification

Postby NickF » 16 Oct 2020, 10:06am

I have a 6 speed Brompton folding bike manufactured in 2004 and I would like to identify the specific Hub gear I have on the bike. Reading around there seem to be all kinds of Hub gears and I read that Brompton themselves changed from Sturmey Archer to something called SRAM around the time my bike was made. I was hoping to find some kind of identification marking or part number, but haven't found anything yet, which may of course be because I am looking in the right place.

Hence my question: How do I identify the specific Hub that is on my Brompton?

Jdsk
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Joined: 5 Mar 2019, 5:42pm

Re: Hub gear identification

Postby Jdsk » 16 Oct 2020, 10:14am

Could you add some photos?

Although with the expertise available around here someone might know without!

Jonathan

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Hub gear identification

Postby Brucey » 16 Oct 2020, 10:42am

at that date it is probably a SRAM hub. If so it will look like this;

Image

SA were not making anything much for about two years (during the move to Taiwan ~2001, ~2002) and it is no coincidence that SRAM had some profitable years selling IGHs at that time. Brompton stuck with SRAM for several years after SA resumed, before changing back to SA from then (~2009?) to the present. From then the hub in a Brompton 6s would be a 'BWR' with an aluminium shell.

cheers
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Brucey
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Re: Hub gear identification

Postby Brucey » 16 Oct 2020, 4:35pm

BTW most of the parts in the Brompton SRAM hub were the same as those found in other SRAM hubs around that time, but some are not. In any event a contemporaneous standard SRAM 3s model can provide many of the spare parts you might need.

cheers
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NickF
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Joined: 16 Oct 2020, 9:45am

Re: Hub gear identification

Postby NickF » 19 Oct 2020, 3:24pm

Thanks for the answers and the photo which seem to confirm I have a steel Brompton SRAM Hub. It will be a help to know with certainty what I have when reading around about the Brompton. Photo of my hub attached.

I came to my question because I have a Torpedo shifter, but have never found it very good, so have been wondering about trying to find something else that will shift between the gears more precisely. But before looking at shifters I figured I needed to find out exactly what kind of Hub I have.

Nick
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simonineaston
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Re: Hub gear identification

Postby simonineaston » 19 Oct 2020, 3:46pm

Just to continue my musings on the subject of product development and history, the brand-name torpedo give a clue as to the origins of the hub - that is to say, it's a product designed and built by the German company Sachs. By 2004, the SRAM Corp had done what it often does, that is target a company that has expertise in a product line they're interested in, with a view to buying them up, thus SRAM took over Fichtel & Sachs in 1997 - see here for details, on Sheldon Brown's website, if you're interested.
byyeee,
SiE

Brucey
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Re: Hub gear identification

Postby Brucey » 19 Oct 2020, 7:01pm

NickF wrote:….I came to my question because I have a Torpedo shifter, but have never found it very good, so have been wondering about trying to find something else that will shift between the gears more precisely. But before looking at shifters I figured I needed to find out exactly what kind of Hub I have...


this is the shifter that Brompton would recommend for both SRAM and SA hubs when fitted to their bikes.

https://www.sjscycles.co.uk/gear-spares/brompton-gear-trigger-3-spd-brompton-sa-sr/

However the most common problem with this sort of setup is the cable; quite minor problems with the cable can result in very poor shifting, regardless of shifter. Your hub looks badly corroded; if the cables are commensurate with the hub, they will be well overdue for a change.

cheers
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rogerzilla
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Re: Hub gear identification

Postby rogerzilla » 19 Oct 2020, 7:10pm

It's the same as a Spectro T3 if you need parts. These are getting trickier as SRAM pulled the plug on hub gears 3 years ago, including ALL spares. Just like that.

Brucey
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Re: Hub gear identification

Postby Brucey » 21 Oct 2020, 6:45pm

rogerzilla wrote:It's the same as a Spectro T3 if you need parts....


I think the driver is different between a 3s T3 and one meant for a 6s Brompton. The internals are otherwise very similar though.

cheers
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geomannie
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Re: Hub gear identification

Postby geomannie » 22 Oct 2020, 9:35am

Brucey wrote:However the most common problem with this sort of setup is the cable; quite minor problems with the cable can result in very poor shifting, regardless of shifter. Your hub looks badly corroded; if the cables are commensurate with the hub, they will be well overdue for a change.

cheers

Amen to that. Brakes & gear shifting on my old Brompton are significantly improved by dribbling of "dry" lubricant down the cables.

If the cabling is too far gone, then replace.
geomannie

NickF
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Joined: 16 Oct 2020, 9:45am

Re: Hub gear identification

Postby NickF » 22 Oct 2020, 10:45am

Hi,
The cable is new. It has been replaced a couple of times since I have owned it. I certainly concur with the comments about the tricky set up, which is why I am grateful for the forum. When it was last serviced - very recently - I was told they thought the Torpedo shifter is worn internally, but they couldn't or didn't want to replace it themselves. Maybe because of the parts sourcing problem already mentioned.

Hence my desire to find the most appropriate replacement, starting from not wanting to get something incompatible with my hub. Thanks for the replacement recommendation and thanks one and all for the comments and help.

nickf

Brucey
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Re: Hub gear identification

Postby Brucey » 22 Oct 2020, 11:30am

trigger shifters are brilliantly simple but do require frequent lubrication if the pawl is not to wear. You can still buy a new 'torpedo' 3s compatible trigger shifter but it is presumably a pattern part (copy of the old Sachs design) rather than a genuine one. I have no idea of the quality vs the real thing; there may be more than one type of copy and I have seen plenty of all sorts worn/broken.

In well-used Bromptons the gear and rear brake cables can have very short lives; if you do a "ride-train-ride-stash in office" type commute then bike gets folded and unfolded at least four times a day (going up to six if the bike is folded at home too which it commonly is because it stands up with the rear end folded) and this knocks merry hell out of the cables near the swingarm pivot. Standard cable housing just isn't designed for this type of fold; well, it won't last anyway; it is a more aggressive loading on the cables than I have seen on any other bicycle. I am not sure if Brompton use special cable housing or not; some at least appears to be standard jagwire housing of some kind, I keep meaning to look into it some more; it just might be worth buying genuine Brompton cables if they last longer, despite their cost.

Anyway what I'm (eventually...) coming round to saying is that in any bike shifting problems always make me think of cables first and in Bromptons that goes double (or maybe even triple). I think that in daily use if the cables last more than a year or two you are probably doing quite well.

cheers
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