I am a happy Brompton owner but in my somewhat hilly locale I find that top gear is unused and that I am always wishing I had something lower at the bottom.
I have seen previous messages relating to lowering the standard gearing. I have a 6 speed machine (T6 I think) and was wondering how to go about it. Is this something I can do myself or is this a job for the LBS? If its DIY can anyone give advise on where to get the cogs and how to fit them?
Any thoughts appreciated. -- Bob Downie Downie GeoScience Ltd. please remove #n0spam# to reply directly
You'll be wanting a chainset with fewer teeth. The smallest official chainset from Brompton is 44T which is a 12% reduction from the standard 50T. Sadly you can't just change the chainwheel (as far as I'm aware).
In the olden 3-speed days, I opted for 18% reduction achieved with a bigger cog and the smaller chainset. That cog dissappeared when I changed to 6 speed (with a wider range).
Any chainset is useable, so if you have one on another bike you can experiment. Some people have fitted double chainsets and a deraileur, others change gear (big to small ring) with their heel or a piece of wire.
A money no object solution is the SpeedDrive, but I won't go there.
You'll be wanting a chainset with fewer teeth. The smallest official chainset from Brompton is 44T which is a 12% reduction from the standard 50T. Sadly you can't just change the chainwheel (as far as I'm aware).
Or a rear sprocket with more teeth, which is a much simpler and cheaper option. 'Reduction' sprockets are a standard part from Brompton.
-- [email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/ There's nae Gods, an there's precious few heroes but there's plenty on the dole in th Land o th Leal; And it's time now, tae sweep the future clear o th lies o a past that we know wis never real.
You'll be wanting a chainset with fewer teeth. The smallest official chainset from Brompton is 44T which is a 12% reduction from the standard 50T. Sadly you can't just change the chainwheel (as far as I'm aware).
Or a rear sprocket with more teeth, which is a much simpler and cheaper option. 'Reduction' sprockets are a standard part from Brompton.
Bear in mind that the shape of the rear triangle will limit the size of the sprocket. IIRC 15 is the maximum---I tried a 16 on mine once and it caught where the drop-outs become the stays---but it's be worth checking.
You'll be wanting a chainset with fewer teeth. The smallest official chainset from Brompton is 44T which is a 12% reduction from the standard 50T. Sadly you can't just change the chainwheel (as far as I'm aware).
Or a rear sprocket with more teeth, which is a much simpler and cheaper option. 'Reduction' sprockets are a standard part from Brompton.
Bear in mind that the shape of the rear triangle will limit the size of the sprocket. IIRC 15 is the maximum---I tried a 16 on mine once and it caught where the drop-outs become the stays---but it's be worth checking.
I was about to mention that I'd sent you one to put on your Brompton, but then I read this. Everyone can feel free to know that the 16 tooth cog in question is doing sterling service as a custom size coaster on my bedside table.
Thanks for your suggestions. If I understand the consensus view, then I should change the 2 rear sprockets for larger ones. The small one should go to 15 teeth but what about the larger?
As my supplementary question, is this something I should attempt myself or is this best done by the LBS (e.g. will I need special tools?).
Thanks again
Bob
In message <[email hidden]>, Ambrose Nankivell <[email hidden]> writes
Quoted message said:
Colin Blackburn said:
Simon Brooke said:
in message <[email hidden]>, daren ([email hidden]'😉 wrote:
> You'll be wanting a chainset with fewer teeth. The smallest official > chainset from Brompton is 44T which is a 12% reduction from the > standard 50T. Sadly you can't just change the chainwheel (as far as > I'm aware).
Or a rear sprocket with more teeth, which is a much simpler and cheaper option. 'Reduction' sprockets are a standard part from Brompton.
Bear in mind that the shape of the rear triangle will limit the size of the sprocket. IIRC 15 is the maximum---I tried a 16 on mine once and it caught where the drop-outs become the stays---but it's be worth checking.
I was about to mention that I'd sent you one to put on your Brompton, but then I read this. Everyone can feel free to know that the 16 tooth cog in question is doing sterling service as a custom size coaster on my bedside table.
-- Bob Downie Downie GeoScience Ltd. please remove #n0spam# to reply directly
