Rohloff_Brompton_Rider
Formerly just_fixed
Apart from very few IGH's , name a set up with the same gear range of the 6 speed Brompton that doesn't use two levers.
Brompton gearing
- Thread starter The Eco Worrier
- Start date
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GrumpyGregry
Here for rides.
As phrased it is a ridiculous question.
I love my Brompton but I'm not blinded to the faults in their approach.
Rohloff_Brompton_Rider
Formerly just_fixed
What the fark you on about? It's an easy question, just answer it.
We've got a customer with a 3 speed internal x 2-speed freewheel/ cassette that needs a new chain and cogs. I've read that the cogs are standard Shimano type cassette cogs and also that they are something special perhaps made just for Brompton? Can anyone confirm what they are? We're in the USA and want to make sure we've got the right parts on hand to replace them for the customer as it's his primary transportation. He's also needing a new left shifter cable/housing. Is that a standard shift/cable & housing or something special for these Bromptons? Unfortunately the bike is no longer here in our shop.
T4tomo
Legendary Member
Is the customers bike a Brompton? - i think yes.
you need the correct sprockets to match the Hub gear fitted, which may be SA or SRAM. They are defo not standard shimano cogs, wipe that thought from your mind. 3/32 size chain needed and the SA / SRAM sprockets to match
shifters are Brompton specific as is the rear "derailleur" shifter
Sorry, yes, it's a Brompton. Thank you for clarifying that these sprockets are NOT Shimano-type cogs and the shift cables/housing are also unique (as I suspected). We'll keep hunting for the correct parts. I've got an email in to Brompton support for help.
Tenkaykev
Guru
Take a look at the excellent Brilliant Bikes YouTube channel, there are lots of really useful and informative videos on there including some gearing specific ones.
Schwinnsta
Senior Member
Shimano spline 2mm
berlinonaut
Veteran
as often: It depends. It it is a newer bike (after 2009) the cogs on the 6-speed S/A hub are shimano-compatible. If it is older they are not as those use an SRAM hub. While you could use Shimano cogs on the newer bike as a customer I would usually expect the correct factory parts. Bromton does have a US distribution and getting the cogs from them should be no big deal and you can be sure that they fit w/o tinkering.
Same goes for the shifters: Cable length is very critical as is cable routing. The correct type of cables depends if the bike was made before or after 2017. Brompton do sell the correct cables for both models in the correct length for the different handle bars. So while it is no big deal to use 3rd party parts the devil is in the detail and if you don't have experience with the Brompton chances are high that you will mess something up w/o recognizing it.
The chain is no issue. Any 8 or 9 speed will do.
If this is your website, I am normally located minutes from you and may be able to help. At this moment I am away, though, and will be back only next week. There is a number of Brompton dealers now in the US, a big shift compared to decade ago when they were just two, and even REI now carries Brompton. For parts I would suggest Perennial Cycle, Clever Cycles, Curbside Cycles (Toronto but little time/price penalty f/over border), J. C. Lind Bike. Co. (Chicago) and Universal Cycles. Brompton shift cables use unusual nipples and uncommon ferrules for housing - I would not try to make the standard cables work in a rudimentary service.
berlinonaut
Veteran
A bike repair center run by a university! THAT is awesome!
While even their existence impacts the local culture, they also undertake various conscious social efforts. Thus, e.g., every year hundreds of bikes get abandoned over the campus by students and longer-term visitors departing the university. Police collect those bikes and the Bike Shop fixes them and offers them at a low price to the incoming students and visitors.
FLYINGGATER
Well-Known Member
Quite common pre WW2 some hubs had 3 sprockets
