Brompton: Replacing the M-Bar with an S-Bar
#1
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Brompton: Replacing the M-Bar with an S-Bar
I just got a Brompton M6R and have begun using it to commute to work. It has been great except that I feel the position is too upright for me. I am now thinking of converting the M-Bar to an S-Bar. I won't be replacing the "M" stem which I understand is shorter than that on "S" series. This suits me just fine as I am used to riding road bikes.
My question is will the brake and shifter cables need replacing too?
My question is will the brake and shifter cables need replacing too?
#2
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From: Cheshire, North West England, UK
Bikes: Brompton S2L-X, Bridgestone Moulton, 1963 & 1966 Moultons, Scott Mountain bike
The current cables would be too long for this conversion and so would the S-Type cables as you would be setting the handle bar lower than they are even on an S-Type. You might after some careful measuring be able to cut down the existing cables to suit.
I have a bespoke S-Type and love the riding position.... I also bought my Dad a Brompton... he wanted an S-Type but none of the dealers had one in stock and he wanted one there and then (he just will not wait haha)....I looked at doing the conversion from M to S and to do it properly you need the S-Type handlebars, stem, cables and I think IIRC also the brake levers.
I have a bespoke S-Type and love the riding position.... I also bought my Dad a Brompton... he wanted an S-Type but none of the dealers had one in stock and he wanted one there and then (he just will not wait haha)....I looked at doing the conversion from M to S and to do it properly you need the S-Type handlebars, stem, cables and I think IIRC also the brake levers.
Last edited by PDR; 03-28-11 at 02:47 PM. Reason: typo
#3
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PDR, thanks for the insight. I just ordered the S-bar online and what I might do is try it out first on my bike and see if it fits on my M-stem. I don't see the S-type stem available online (NYCEWheels) but as I said if the S-bar fits I will probably stick to my M-stem since it makes for an even lower riding position which I prefer for medium to loner range riding. I might just cut the existing cables as you suggested.
#4
The Brompton handlebars are not custom-sized. You can use just about any non-oversized MTB bar that has the 25.4mm stem clamp. I mocked up a M-stem with an old Bontrager Ti handlebar and PDR is correct in that the cable housings needed trimming. However, that's not hard if you're handy around the bike. The handlebar may also need to trimmed for length, so that it doesn't affect the fold.
#5
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This looks like a good piece,https://www.thorusa.com/dahon/technical/aberhallo.htm
So bar not so low, when not getting the rest of the S bar setup..
Which is available if you ask the right question, allow domestic dealer order/ship delay..
Or, want to just click over the web? Retail import from UK? https://www.sjscycles.co.uk/brompton-...att-prod20013/
So bar not so low, when not getting the rest of the S bar setup..
Which is available if you ask the right question, allow domestic dealer order/ship delay..
Or, want to just click over the web? Retail import from UK? https://www.sjscycles.co.uk/brompton-...att-prod20013/
Last edited by fietsbob; 03-26-11 at 07:48 PM.
#7
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From: San Francisco Bay Area
Bikes: 2005 Fuji Professional, 2002 Lemond Zurich, Folders - Strida, Merc, Dahon, Downtube, Recumbent folder
Question: does the S type stem give you more top tube reach as well? Or just lower height?
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#8
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the Mast , stem, for the S bar is taller than the M bar ,
and the S bar mast has a bend in it , so bar clamp further forward.
but the bar, as it has no rise , will be lower,
so only using the lower S bar front bag won't interfere with the steering,
and braking.
brake levers being the lowest contact point.
and the S bar mast has a bend in it , so bar clamp further forward.
but the bar, as it has no rise , will be lower,
so only using the lower S bar front bag won't interfere with the steering,
and braking.
brake levers being the lowest contact point.
Last edited by fietsbob; 03-31-11 at 01:01 PM.
#9
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hi all, i actually did this mod on my bike. took my original M-type to the local brompton dealer and asked them to install the S bar instead. size is the same, no issues with length and even with added grips and bar ends, the fold was not affected. all the cables did have to be cut down to length though.
#10
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Nice to know this ansikutero. The S-bar I ordered will be arriving today. Instead of cutting the existing cables, I intend to just get new ones for the S-bar. In case I decide to put the M-bars back I will still have the original cables.
What model of Ergon grips/barends are those in your pic? They look nice. Can you still fold the bike without adjusting/twisting the Ergon grips/barends?
What model of Ergon grips/barends are those in your pic? They look nice. Can you still fold the bike without adjusting/twisting the Ergon grips/barends?
#11
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The only issue I've had with them is that they're long, and the stock Brompton brake levers have a plastic wedge that doesn't let you align the levers to the edge of the grips. (You can see what I'm talking about from the picture I posted.)

For someone with shorter hands like myself, it's a pain trying to shift gears. Originally, the plastic wedge was over the original foam grips. Other people have ended up cutting their grips to make way for the ledge, or you could buy shorter grips meant for grip-shifters. I like these grips too much to give them up so I ended up changing the brake levers for Shimano R770's instead.
Last edited by ansikutero; 04-11-11 at 02:08 AM.
#12
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Thanks for the followup. My S-bar arrived last week and I am about to place an order online for Ergon GR2s. I understand the "plastic wedge" issue that you pointed out and this is the reason I am still wondering if I should order the shorter "grip shift" version of the GR2s. However I might just get the regular version, try them out, then cut off an inch or so from the inside if it interferes with shifting.
#14
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From: Jersey City, NJ
Bikes: 1994 Diamond Back Racing Prevail ti; Miyata 914, Miyata 1000, 2017 Van Nicholas Chinook
I have an extra S-Type bar (recently upgraded my original to a Ti version of similar angle). Just PST me if interested.
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#15
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Pondering on S type riser stem + aber hallo + MTB riser bar to get me back to M bar height,
but not have the big u in the middle, and maybe a bit more angle sweep..
M riser is 29cm, bottom of hinge plate for the upper part to the Bar clamp center ..
So what is the S riser stem measure out to?
but not have the big u in the middle, and maybe a bit more angle sweep..
M riser is 29cm, bottom of hinge plate for the upper part to the Bar clamp center ..
So what is the S riser stem measure out to?
#16
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Hi fietsbob, (**** U ook nederlands spreken?)
I wondered if you figured out a way to use the "S type riser stem + aber hallo + MTB riser bar to get me back to M bar height"
I have a S2L-X, raw that I'm feeling a bit uncomfortable with. I believe increasing the bar height would help. Purchasing a completely new M stem and bars and cables is beyond my budget.
What has been your experience?
I'd be happy to move this to a general discussion if you wish.
Thanks,
Clark
I wondered if you figured out a way to use the "S type riser stem + aber hallo + MTB riser bar to get me back to M bar height"
I have a S2L-X, raw that I'm feeling a bit uncomfortable with. I believe increasing the bar height would help. Purchasing a completely new M stem and bars and cables is beyond my budget.
What has been your experience?
I'd be happy to move this to a general discussion if you wish.
Thanks,
Clark
#17
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Alstublieft, Just Visited several Times .. European cycle tours started from Shiphol.
The H riser , other than the hinge being higher off the headset .. turns out to be close to the Riser for The S bar ..
the riser for the M bar is is Lower than Both.. Build Your Brompton
there are Brompton Modifying shops ( one in NL, Brompton aanpassingen ),
to cut the head off the steering riser and add a QR telescoping inner post.
perhaps You have a Local Bike Frame builder willing to take on a similar job?
the Aberhallo and its Ilk is a 2 clamp pair which is a 1" tube that goes thru where the bar mounts
then the upper clamp pair holds the bar , aberhollow is offset many others are straight ..
https://www.bikeforums.net/folding-bi...-extender.html
the Center Bulge in many bars is not that wide , just wide enough to grip with the stem , then the rest is 7/8"
The H riser , other than the hinge being higher off the headset .. turns out to be close to the Riser for The S bar ..
the riser for the M bar is is Lower than Both.. Build Your Brompton
there are Brompton Modifying shops ( one in NL, Brompton aanpassingen ),
to cut the head off the steering riser and add a QR telescoping inner post.
perhaps You have a Local Bike Frame builder willing to take on a similar job?
the Aberhallo and its Ilk is a 2 clamp pair which is a 1" tube that goes thru where the bar mounts
then the upper clamp pair holds the bar , aberhollow is offset many others are straight ..
https://www.bikeforums.net/folding-bi...-extender.html
the Center Bulge in many bars is not that wide , just wide enough to grip with the stem , then the rest is 7/8"
Last edited by fietsbob; 05-27-14 at 10:10 AM.
#18
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Dear cyclocommuter, how was the change? Did everything work correctly? Did you cut the S-cables? What is your experience? Too low with the M-stem or ok? Thinking about switching as well. And can't change the stem, because I have the Explore special edition and the green colored stem exists only in M.
#19
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This thread was started in 2011, the M stem and M handlebar have changed since then, the current M stem is higher and the current M handlebar is lower (the total height stem+handlebar is about the same).
Putting a S handlebar (or any flat handlebar) on the current M stem (as on the Explore) will result in a higher position than with the old M stem. Cables length reduction will be less than what it was with the old M stem.
Putting a S handlebar (or any flat handlebar) on the current M stem (as on the Explore) will result in a higher position than with the old M stem. Cables length reduction will be less than what it was with the old M stem.
#20
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Hi Jipe, Thanks for the quick answer. In order to have a sustainable switch, I will do like cyclocommuter planned: ordering some new S-cables for brakes and gears and keep the old ones for the M-Bar, in case if I ever want to switch back. Although the difference will be not that big anymore (like 2011), I still have to shorten the S-cables?
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