Brompton gearing

[The Eco Worrier]

I have a 3 speed Brompton, I understand they can be converted to 3+ by messing with the gearing ratio. Does anyone know how to do this?

Thanks

 

[T4tomo]

You can retro fit the derailleur to convert to a six speed, but to be honest I wouldn't bother as the change is then fiddly for sequential gearing.

alternatively, if you thinnk you neeed highr or lower gears then you can change the chainring and or sprocket size.

 

[jay clock]

I changed the front ring for 46T on my S3L - means I am able to cycle up hills spinning nice and fast, and use 2/sometimes 3 on the flat. Steeper downhills I coast. Suits me perfectly

 

[The Eco Worrier]

Adrian,I can see form the order form they are now calling it raised gearing

So 3 speed with raised gearing as opposed to 6 speed.

Jay, I think by changing to 46t I would have a lowered gearing which is not what I am after.

 

[jay clock]

@The Eco Worrier yes you are right, but that is what i wanted.! I tend to spin like a dervish and although I do not have many steep hills to climb I use the first gear daily

 

[CopperBrompton]

Yes, you can fit a bigger or smaller chainring to raise or lower the gearing. There are three standard ring sizes approved by Brompton.

 

[rualexander]

Yes, you can fit a bigger or smaller chainring to raise or lower the gearing. There are three standard ring sizes approved by Brompton.

Or you can use any size chainring you like if it fits the chainset, or change the chainset and fit smaller still rings or fit a double chainring to give two ranges and move the chain between rings by hand.

 

[The Eco Worrier]

Or you can use any size chainring you like if it fits the chainset, or change the chainset and fit smaller still rings or fit a double chainring to give two ranges and move the chain between rings by hand.

I like the idea of a stop and rest between gear changes, especially on the hills!!

I have a 50T front chainring and 13T rear, so it looks like I can up the front one a bit.

Thanks all!

 

[jay clock]

If you email Brompton via their tech support website they are very good

 

[T4tomo]

I like the idea of a stop and rest between gear changes, especially on the hills!!

I have a 50T front chainring and 13T rear, so it looks like I can up the front one a bit.

Thanks all!

Yes you can go upto a 54T which is what I used to run before I moved to a hillier area and switched to 50-13.

 

[Crankarm]

You can retro fit the derailleur to convert to a six speed, but to be honest I wouldn't bother as the change is then fiddly for sequential gearing.

alternatively, if you thinnk you neeed highr or lower gears then you can change the chainring and or sprocket size.

Not in my experience.

 

[TheDoctor]

^^This. I don't find the gearchange fiddly at all on my 6 speed Brommie.
Having said that, I could swap out the 50T chainring for a 40T, losing the 99" top gear and gaining a 22", which would be more useful to me. I haven't, as that means the change between my two most-often used gears would be a double change, and I'd sooner not do that every few minutes.
But the gearchange isn't an issue in everyday use.

 

[GrumpyGregry]

Yes, the Brompton six speed gear shift is such an awesome solution many of us are completely baffled why every other manufacturer has not adopted it.

 

[TheDoctor]

I know - having two gear levers is a stupid idea. It'll never catch on!

 

[sreten]

Yes, the Brompton six speed gear shift is such an awesome solution many of us are completely baffled why every other manufacturer has not adopted it.

Hi,

Because a 2 speed derailleur and 3 speed hub makes no cost sense compared to a 6 speed derailleur,

rgds, sreten.