Brompton stem Q.

[404 Not Found Anywhere]

As the years creep on my urge to be low and speedy has been replaced by being more upright and leisurely. I’m also not bending in the middle as well as I did!

A few years ago whilst doing a few other adjustments I bought a pair of J K riser bars to bring my S6L’s handlebars up to M-bar level. Now I’m wondering about getting the bars a bit closer. Can anyone advise on how much an M-style stem will move the bars closer to the saddle? Obviously I’m going to have to fit M-bars as well but the cables are the right length if I go down this route.

Gratuitous picture of my bike on the old railway track running up the side of the River Livet (as in whisky)

 

[mitchibob]

I'm not sure you'll find any difference. In the past, I believe the S-bar stem was actually a little taller than the M-bar one (at least with the more traditional M-bars) and was the same height as the H bar variant. After they changed to more mid-rise bars, I think the stems remained the same.

 

[ktmbiker58]

How about finding a local engineering workshop and see if they can flatten the bend a bit although effectively it will shorten the effective stem length so the steering might be more direct

 

[404 Not Found Anywhere]

My reading suggests there is a difference: the JK bars bring the handlebars to the same height as the M bars but images of the stems suggest there are differences apart from length. And I prefer things to be reversible in case they don’t work. There are some second hand stems about that might be worth a punt on, obviously I will need new handlebars too - though one thing I like about the JK bars is that they are wider than the stock ones.

I think the easiest and most direct way is to hire a Brompton Dock bike for a bit and see how it compares (AFAIK they are all M-style)

 

[mitchibob]

I think the easiest and most direct way is to hire a Brompton Dock bike for a bit and see how it compares (AFAIK they are all M-style)

That'll just validate the stem length, depending on age of those bike (brommie lasts forever though). Pretty sure you already have the tallest stem. Just need to get some old style M bars.

I have some on a 2016 M2L that I really should sell as never use it since getting M6E, and over time converting to S6L, except stem.

 

[404 Not Found Anywhere]

Well, as an update, I hired a C-Line Urban 3 speed from Brompton Dock over the weekend for a direct comparison.

The differences are surprisingly minimal; I think changing back to the Brompton saddle will help a lot, as the Rolls saddle I currently have doesn’t go anything like as far forward on its rails. Fine for when I was riding longer and faster when it was a S-model, not quite so practical with the more raised bars. A little tweak of the handlebars made quite a difference too.

I was also very pleased to discover that there is not much difference between my 2009 bike and the current models. (I upgraded the shifters and brake levers when I swapped the bars - a definite improvement functionally and aesthetically on the rattly bunny ears shifters). So a) I don’t need to worry about trading in my old faithful and b) I can justify a titanium seatpost to replace my rusting chrome steel one 😁

I also quite liked the simplicity of the dynamo lighting too…

 

[Kell]

These images might help.
Each of these older style stems was different, with the M type having the least amount of curve. What they are (unfortunately) missing is the height of the bar clamp. I remember when buying mine, I couldn't find that info anywhere. But it does at least show you relative heights and bends.

 

[404 Not Found Anywhere]

My question wasn’t about the height of the bars - the JK bars bring the handlebars up to the same height as the M bars. It’s the reach I was trying to tweak - in your diagram the axle to handlebar distance. It shows clearly that the S bars are further forward than the M bars. In the end leaning the bars a bit more backward, however dorky it looks, is half way to being more comfortable and I think I’ll probably be able to make up the rest by refitting the standard Brompton saddle (when I can find it!)

 

[Kell]

My question wasn’t about the height of the bars - the JK bars bring the handlebars up to the same height as the M bars. It’s the reach I was trying to tweak - in your diagram the axle to handlebar distance. It shows clearly that the S bars are further forward than the M bars. In the end leaning the bars a bit more backward, however dorky it looks, is half way to being more comfortable and I think I’ll probably be able to make up the rest by refitting the standard Brompton saddle (when I can find it!)

I know.

It’s one image, so you can just ignore the bits that aren't applicable.

There's no need to say thank you.

 

[T4tomo]

https://www.bikefolded.com/brompton-s-m-p-h-type-handlebar-differences/

@404 if you've put M bars on an S stem, you've got yourself a H type, subject to 2017 handlebar changes to the M style bars. throwing JK makes a small diff, not a lot. tweak bar angle for reach.

 

[404 Not Found Anywhere]

I know.

It’s one image, so you can just ignore the bits that aren't applicable.

There's no need to say thank you.

My bad 🫢

thank you, it was helpful!