Brompton Mods

[Gandi]

Hello,
I have searched through all 44 pages but cannot find anyone who has listed or mentioned the particular modification I am after doing.
I have a S2L but only being 165cms (5’5”) tall I want to go lower at the front. At the moment I can’t find any measurements of the different model stems (handlebar supports), I have seen diagrams and pictures showing the different overall height’s at the top of the bars but doesn’t show the stem lengths. I was thinking of fitting a “P” stem and if was too low I would fit something like a pr of Ritchie 30mm riser bars.
So does anybody know the height of the different stems.
Now for next mod, I am riding my Brompton using 44 x 16/12 and I was/am going to go to 14/12 but then this gives me a good alround every day gear and a bigger gear for tailwind and down hills, but a bit of thought I would be better making it into a 3 speed and keeping it 16/14/12 this then gives me a gear for the hills. So can it be done ?.

Cheers and thanks for looking

 

[steveindenmark]

Go on the FB Brompton site and ask. Someone on there will know.

 

[berlinonaut]

I have searched through all 44 pages but cannot find anyone who has listed or mentioned the particular modification I am after doing.
I have a S2L but only being 165cms (5’5”) tall I want to go lower at the front. At the moment I can’t find any measurements of the different model stems (handlebar supports), I have seen diagrams and pictures showing the different overall height’s at the top of the bars but doesn’t show the stem lengths. I was thinking of fitting a “P” stem and if was too low I would fit something like a pr of Ritchie 30mm riser bars.
So does anybody know the height of the different stems.

The P stem is about the same height as an M stem (version before 2017). You can combine either of those with an S bar and would probably be happy. The M stem is way easier to get hold of used than a P stem. The older version measures about 30cm from top of the headset to middle of the bar clamp. The newer M stem from 2017 on is slightly higher - about 2,5 cm. The H stem before 2017 has about the same height as the S (which you can measure yourself as you own it), the newer one is slightly higher - so both not an option for you.

Now for next mod, I am riding my Brompton using 44 x 16/12 and I was/am going to go to 14/12 but then this gives me a good alround every day gear and a bigger gear for tailwind and down hills, but a bit of thought I would be better making it into a 3 speed and keeping it 16/14/12 this then gives me a gear for the hills. So can it be done ?.

Yes, not a big deal. I've done the same mod on a 6-speed BWR (ending up with 9 gears) and it can be done identically with a 2-speed.

 

[berlinonaut]

Go on the FB Brompton site and ask. Someone on there will know.

Why? Someone here knows (and I am not on Facebook, so I wouldn't know there). What purpose does a forum have if the only answer to a question is "go on Facebook and ask there"?

 

[steveindenmark]

Because more Brompton questions are answered on the FB site. There are more Brompton owners on the Brompton FB site and therefore more experience. Brompton questions are replied to quicker on the Brompton FB site. This is not a Brompton site. It is a folding bike site

If you can find someone to point you in the right direction on here. Does that not serve its purpose?

 

[12boy]

To answer your questions......
You can use a riser bar or several other bars such as North Roads and flip them which can drop your hand position. Both getting your saddle farther forward and using a bar like a North Road that gets your hand position behind the stem can make your reach easier. The Pentaclip saddle clamp can be reversed to make the saddle ride higher or lower and place you closer or further from your bars.
As far as gearing goes, Bike Gang sent me a proto type sprocket set with 11, 14 and 17 tooth sprockets that was very easy to swap out for the two sprocket normal set up. It works exactly as the two sprocket set, just giving a higher high, an intermediate gear and a lower low. The only drawback I can see is that the 11 tooth sprocket will wear out first and it's a one piece set, so you can't just replace it the 11 tooth.
I am enclosing pictures of my B with moustache bars to illustrate the handle bar drop and rearward hand placement.
In my mind, moving the saddle and replacing the bars with something that drops them down will be easier and much less expensive than getting a new stem and then moving everything over.
BTW, Ergon grips are nice on Bromptons as they soak up some road chatter.

 

[berlinonaut]

Because more Brompton questions are answered on the FB site. There are more Brompton owners on the Brompton FB site and therefore more experience. Brompton questions are replied to quicker on the Brompton FB site. This is not a Brompton site. It is a folding bike site

So why are you here then if Facebook is so much better than any forum could ever be and a forum is worthless by definition? From my personal experience a lot of people are not on Facebook and will never be, especially the more experienced ones. Facebook on the other hand is so famous for incompetent and obviously wrong and false information in all areas that they have been forced to install fake news checker teams...

 

[steveindenmark]

So why are you here then if Facebook is so much better than any forum could ever be and a forum is worthless by definition? From my personal experience a lot of people are not on Facebook and will never be, especially the more experienced ones. Facebook on the other hand is so famous for incompetent and obviously wrong and false information in all areas that they have been forced to install fake news checker teams...

Because I have 8 other different bikes. Not just a Brompton. Your very strange. 😳

 

[Gunk]

Here are the different combinations of stems and bars

What you could do is to fit an “M” stem with a low rise bar

https://www.ebay.co.uk/itm/264382727766

 

[Tenkaykev]

Here are the different combinations of stems and bars

View attachment 515065


What you could do is to fit an “M” stem with a low rise bar

https://www.ebay.co.uk/itm/264382727766

Just thought I'd mention that SJS cycles and Brilliant Bikes etc has these in stock for about £20. Nowt wrong with the Ebay ones but they have to travel all the way from Hong Kong.

 

[rualexander]

I recently put a three sprocket conversion kit on my Brompton, it was the MiniMods one from SJSC

https://www.sjscycles.co.uk/sprockets/minimods-brompton-3-cog-upgrade-kit-12-14-17t/

Out of stock just now but maybe available elsewhere. Not sure about different sprocket combos.

Works well, I just got a cheap friction front changer to go with it. If you currently have a 2 speed shifter then you may be able to modify it to 3 depending on the version, otherwise a new shifter will be necessary.

 

[berlinonaut]

Here are the different combinations of stems and bars

View attachment 515065


What you could do is to fit an “M” stem with a low rise bar

https://www.ebay.co.uk/itm/264382727766

What the OP was asking for is exactly the information that is missing from this as well as from the other usual illustrations: what height do the stems have on their own, w/o the bars. So your info is correct but somewhat missing the point the OP was asking for. As I wrote several postings earlier the old M stem (as shown in your pic) is about 30cm. The old H stem is about 36,5 cm. S is about the same as the old H, P is about the same than old M, the newer M and H are more or less 2,5 cm more.
Brompton said on it's invention 2012 the H would be ~6 cm higher than the M. The old H has the bar height from the ground at ~93cm at the clamping area (and Brompton claim 92,4 cm of height for the S bars with S-stem). So with the old M stem or the P stem combined with Brompton S-bars one should end up at more or less 86,5-87cm of bar height.

 

[berlinonaut]

I recently put a three sprocket conversion kit on my Brompton, it was the MiniMods one from SJSC

https://www.sjscycles.co.uk/sprockets/minimods-brompton-3-cog-upgrade-kit-12-14-17t/

Out of stock just now but maybe available elsewhere. Not sure about different sprocket combos.

Works well, I just got a cheap friction front changer to go with it. If you currently have a 2 speed shifter then you may be able to modify it to 3 depending on the version, otherwise a new shifter will be necessary.

The OP was asking for 12-14-16 - not the 12-14-17 the minimods-kit offers. Furthermore the 44 Pounds for the kit seem a bit ambitious. You can simply buy Shimano sprockets and use them: 12t, 14t, 16t - alltogehter this will cost you a freaking 9€. You will need a new chain (9 or 10 speed, depending from the sprockets you are using). You will need to modify your shifter or buy a Sunrace friction shifter. You won't need the spacer from the minimods kit as you can use your existing one and you can also reuse your existing lock-ring after filing on the 12t sprocket or create one from an old spoke. So you end up with 9€ of cost instead of 44 Pounds and you have the spacing you wanted instead of what Minimods offer. For the difference in price you can buy the missing bits like chain and shifter (that you would have to buy additionally to the upgrade kit anyway) plus a couple of beers to consume during and after the conversion.

 

[Gandi]

Cheers for the replies,
Just a little bit of info I missed out on my original post, as I mentioned I have the “S” bar set up and the stem is 35cms tall/length.

Thanks.

 

[Fab Foodie]

So why are you here then if Facebook is so much better than any forum could ever be and a forum is worthless by definition? From my personal experience a lot of people are not on Facebook and will never be, especially the more experienced ones. Facebook on the other hand is so famous for incompetent and obviously wrong and false information in all areas that they have been forced to install fake news checker teams...

Are you for real?
Put your prejudice to one side and you’ll find there are some fabulous Brompton member sites with serious knowledge and global experience of every facet of Brompton modification and customisation.
Jeez...You can lead a horse to water.....