# Brompton 44 teeth?



## Summerking (3 Jul 2013)

I'm sorry if the answer to my post is contained elsewhere but I was having difficulty getting it clear in my mind.
What I would like to know is My Brompton L6 has a 44 tooth front chainring that I just counted sat in the damp back porch at midnight as you do, and I wanted to know can I make the bike's gearing easier for hills? my part of Cornwall has some seriously steep hills that has me off the Brompton and pushing, I consider my self cycling fit but the hill in Lowertown in Helston I challenge anyone to ride a Brompton up!
I,m in the easiest gear and stood on one pedal at a time and barely moving, in contrast an old Trek mtb I had came with an excellent 'spinning' gear that would see the same hill off no trouble, Do I get a bigger or smaller front chainring to get easier gearing? or is 44t as easy as it gets up front?
thanks in advance.
Summer.


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## Pale Rider (3 Jul 2013)

You need a smaller ring at the front for easier gearing.

It appears that at 44t, you already have the smallest ring supplied by Brompton.

However, a ring's a ring, and this company supply a 40t chainset which would give you reduced gearing.

http://www.tillercycles.co.uk/page6.html#projectx

Not cheap at £50, perhaps someone else on here knows of cheaper.

Fitting the chainset is straightforward, but you will need to remove a link or two from the chain.

Some expertise required there, so I would be getting a quote from the local Brommie dealer for the work.


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## Summerking (3 Jul 2013)

Pale Rider said:


> You need a smaller ring at the front for easier gearing.
> 
> It appears that at 44t, you already have the smallest ring supplied by Brompton.
> 
> ...


Thanks Pale Rider


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## RecordAceFromNew (3 Jul 2013)

Summerking said:


> I'm sorry if the answer to my post is contained elsewhere but I was having difficulty getting it clear in my mind.
> What I would like to know is My Brompton L6 has a 44 tooth front chainring that I just counted sat in the damp back porch at midnight as you do, and I wanted to know can I make the bike's gearing easier for hills? my part of Cornwall has some seriously steep hills that has me off the Brompton and pushing, I consider my self cycling fit but the hill in Lowertown in Helston I challenge anyone to ride a Brompton up!
> I,m in the easiest gear and stood on one pedal at a time and barely moving, in contrast *an old Trek mtb I had came with an excellent 'spinning' gear that would see the same hill off no trouble*, Do I get a bigger or smaller front chainring to get easier gearing? or *is 44t as easy as it gets up front?*
> thanks in advance.
> Summer.


 
You can get the 40T stronglight 55 Pale Rider suggested from Spa for £20+p&p. 38T I believe is the smallest for that model.

The issue is it still might not be low enough for your hills, and putting on a smaller front ring will also lower your highest gear. The best way to pick the optimal compromise is to figure out, perhaps using your mtb, to find out what is the highest lowest gear and lowest highest gear you can live with, and see whether we can duplicate that range, in terms of gear inches (not teeth counts because the wheels aren't the same size) on the brompton. A general purpose gear calculator for the mtb and a specialised one for the brompton (pick sram 6-speed in the first dropdown menu for the L6 I think) will be necessary for such an exercise.


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## Summerking (4 Jul 2013)

RecordAceFromNew said:


> You can get the 40T stronglight 55 Pale Rider suggested from Spa for £20+p&p. 38T I believe is the smallest for that model.
> 
> The issue is it still might not be low enough for your hills, and putting on a smaller front ring will also lower your highest gear. The best way to pick the optimal compromise is to figure out, perhaps using your mtb, to find out what is the highest lowest gear and lowest highest gear you can live with, and see whether we can duplicate that range, in terms of gear inches (not teeth counts because the wheels aren't the same size) on the brompton. A general purpose gear calculator for the mtb and a specialised one for the brompton (pick sram 6-speed in the first dropdown menu for the L6 I think) will be necessary for such an exercise.


Thankyou RecordAceFromNew


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## Brommyboy (4 Jul 2013)

I run a Stronglight 44T with a 28T outside of it, which came from Spa. I am going to fit a 36/46 combination when the transmission is replaced, on my Sram 6-speed. OK, you do have to manually derail the chain ring, but this is not done all the time, and the chain must be on the larger ring for folding, otherwise the chain falls off. My friend in the hilly part of Wales runs his similar model on a 38T and finds that suitable. A lot depends on whether you have a 3 or 6 speed model, and on how good your legs are! Riding the Swansea 100 mile ride two weeks ago, I did not use the 28T at all, even though our route went over the Black Mountain, but on some of the much shorter, steeper climbs I hopped off and pushed without losing any time.


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## nomdeplume (7 Jul 2013)

To criticise the Brompton is akin to criticising Mother Teresa or the NHS but I do wonder about the gearing. I had to change the 55T chainring for a 44T and now I find the lowest gear is OK for me, but the original meant that any hill more than about 10% was almost impossible.


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## Brommyboy (14 Jul 2013)

The standard Brompton has a 50T chain ring. The designer saw no need for lower gearing in London. The bigger 54T chain ring is used for the two speed.


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## GrumpyGregry (14 Jul 2013)

Sturmey Archer chainsets fit perfectly and come in a wide range of tooth sizes.

If you are a regular road cyclist in SE England you'll probably find a B chronically under geared. If not, and that the vast majority of the cycling population of the UK, you may find it over geared.


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## TheDoctor (24 Sep 2013)

The BWR hub would be a way round this - the six gears range from 99" to 33" IIRC, using the standard chainring.
Of course, it's an expensive fix...


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## CopperBrompton (24 Sep 2013)

There are lots of solutions if a simple chain-ring swap doesn't do it.

I have the 8-speed SA hub in place of the 3-speed, which gives me a range of 33-107 gear inches with fairly close-ratio gears. That's enough to be comfortable up the steepest hill with a dodgy right knee and still hit 30mph down the other side. 

It's a little OTT for central London, but the beauty of that kind of range with indexed gears is you can choose which ones you use. In London, I start in 2nd, shift straight to 4th, then 6th, then 7th.

http://www.benlovejoy.com/cycle/brompton/


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## T4tomo (26 Sep 2013)

rather than fart about changing the chainring why not just whack a larger sprocket on the back, thats a cheaper fix - how many teeth have you got on the back. can you change the smaller of the two for a couple of teeth above the larger, sprockets are only a fiver, although you may need a slightly longer chain too? I only run a 3 speed - some one might correct me that the deraileur wont cope or something.


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## sreten (6 Oct 2013)

Hi,

Apparently the L6 can be supplied with 12% lower gearing but they don't explain how.
Perhaps the standard 13T and 15T rear sprockets are replaced with 15T and 17T.

rgds, sreten.


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## Pale Rider (7 Oct 2013)

sreten said:


> Hi,
> 
> Apparently the L6 can be supplied with 12% lower gearing but they don't explain how.
> Perhaps the standard 13T and 15T rear sprockets are replaced with 15T and 17T.
> ...



Brompton lower the gearing by using a smaller front chain ring, which the OP already has.

For those with the higher gearing, Brompton will supply the smaller ring for retro-fitting via a dealer.

Mine cost about £25, including a new left crank.

A ring's a ring, and they can be found cheaper elsewhere, although I just let the dealer get on with it.

Fitting is simple enough, but the chain needs to be shortened by a couple of links and I didn't fancy trying that.


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