Dutch-made Brompton telescopic handlebar stem

[snazpizaz]

Hi - cheers
1. @ B-onaut - you mentioned a DIY on a brompton board - and you seemed concerned about cutting down seat posts etc. I haven't yet go to looking at it.
2. QR @ handlebar clamp - yes - exactly - i need to twist the handlebars down for folding and this requires a quick release at the clamp. I've done some initial posting on the subject and it's an option people use - eg:
https://www.bikeforums.net/folding-...nd-quick-release-bolt-brompton-handlebar.html
Others share your safety concerns but i suspect it's about sourcing and matching good quality suitable parts. The Andros is designed to be used on a constant basis - so simple QR levers may have that capacity too. With the dutch-telescopic there's still more stability than with a double riser combo. The number of QRs/securing bolts get reduced to just one at the clamp.
3. QR / lock @ telescopic stem - B-onaut mentioned some concerns about the durability of these if i understand correctly - but i'm not so familiar with their failure rate. I'm assuming any used by the guy building it will be discussed and prove suitable. I can see how a welded bar will eliminate the issue. I've not yet posted anything on this subject to solicit wider opinion but as the option exists in components i'm assuming it can be considered as safe to a degree. I guess the degree depends on intended use.
3. In theory i don't need to telescope the riser, Though i wont say no to a handlebar positioned slightly higher than the current H type bar placement. I guess up to another 10mm of height would suffice if feasible / worth the cost. The main thing is that the extended length reaches current h type stem height with m type handlebar mounted. It seems to me any telescopic/welded bar will clear the wheel axle folded.

If i go this route i'll have a chat with the guy who'll be doing it and i guess that will produce the options. I can bring some of this content to the discussion - cheers
sp

 

[berlinonaut]

1. @ B-onaut - you mentioned a DIY on a brompton board - and you seemed concerned about cutting down seat posts etc.

Don't know where you are getting this from and I surely did not write a single word about "cutting down seat posts".

2. QR @ handlebar clamp - yes - exactly - i need to twist the handlebars down for folding and this requires a quick release at the clamp. I've done some initial posting on the subject and it's an option people use

I use one on my Brecki and it works fine - but, being a recumbent, there is no force applied to it while riding. Others use it with conventional stems and it seems to work there, too. Still it is only holding the bars horizontally, so if it gives up it will surely be unpleasent but you still will be able to steer and brake. Whereas if the quick release on the dutch stem is giving up your stem is moving vertically AND sideways. You would loose the ability to steer as your bars and your movement of those are no longer influencing the front wheel and this will almost surely lead to a crash.

The Andros is designed to be used on a constant basis - so simple QR levers may have that capacity too.

Yes, but it is using two clamps, so you have double the force and an additional layer of saftety through the two clamps. Plus the clamps have a saftety mechanism (at least Andros version one had).

With the dutch-telescopic there's still more stability than with a double riser combo.

That's for sure.

The number of QRs/securing bolts get reduced to just one at the clamp.

That's rather a disadvantage than an advantage in terms of saftety.

3. In theory i don't need to telescope the riser, Though i wont say no to a handlebar positioned slightly higher than the current H type bar placement. I guess up to another 10mm of height would suffice if feasible / worth the cost. The main thing is that the extended length reaches current h type stem height with m type handlebar mounted.

Ergonomically the H bar is way too high for most people apart from the tallest ones, still people seem to like it. If you are using a Toulouse bar you have far less reach to the grips thus you will need way less height than with more reach/a "normal" bar. Higher than H would be basically like on a Dutch bike and possibly not very comfy or ergonomic on a Brompton.

 

[12boy]

Been using a QR for 6-7 years and no trouble with it whatsoever except with a Velo Orange Milano bar, shaped much like the Toulouse bar you have shown. The clamp on the Brompton handlebar post is narrow and the leverage exerted on the the handlebar grips is considerable since the hand position is far behind the clamp. My Milano would slip down even when the QR was extremely tight. I switched it out to a Soma moustache bar and the problem went away. With standard Brompton bars the hands rest inn a line with the clamp so there isn't the the downward torque the Milano bar has.

 

[snazpizaz]

Hi cheers folks:

@b-naut
1. your mentions:
"If you want to create a mod like that yourself: I think in the picture archives of the bromptontalk mailing list that just moved over to groups.io is a picture story of someone who did it himself "
"way less frightening than the seatpost solution but unfortunately not cheap either" - in 'neutral' summary - presuming it meant a cut-down seatpost solution.
2. I've had some feedback questioning if the Andros is that reliable, with reference to it's composite metals and a lack of user history, where as you seem a fan.
3. On more vs less bolts / clamps: I disagree in that i tend to think the less clamps/ bolts along the length of a stem, that need constant checking and tightening the better for reducing experience of failure but i agree QR at the clamp needs to be robust.

@12boy
1. I changed over to the Toulouse following (your ??) advice about the initial ones i choose (velo porteur) not being workable on a brompton due to the small width, which i totally understood. I went for a similar brommie width which ended up being the Toulouse at 560mm - which is 10mm more than H type handle. You mention the milano and soma, , the latter which i think is :
https://www.somafab.com/archives/product/3-speed-moustache-bar
2. If i go the stem riser route, my Toulouse is sitting on the following:
https://www.aliexpress.com/item/4000223670625.html
at brommie stem and then:
https://www.ternbicycles.com/gear/472/andros-stem
to make up the height of the h type handlebar - (m handlebar height 155mm)
2a) You seem to be saying you inserted the Soma directly into the brommie stem clamp where as i propose a double riser set up with a double width clamp in the form of the two Andros stem arms centrally positioned at higher height, to produce approx 34mm of clamp width.
2b) I will have rejected the soma because it's 60mm drop means it sticks out 6cm more when folded where as all the other bars have negligible extension when folded. I note it's smaller width, being 505mm, some 450mm shorter than H type - but you found success with steering when directly inserted into the brommie clamp, i guess it's because the flared grip angle of the Toulouse/Milano isn't present, being at 90 degrees.
If i replicate your reported loose clamp issue with the Toulouse, the replacement i favour is the nitto choc over the soma because of the drop issue:
https://www.rivbike.com/products/nitto-choco-norm-bar-alu-ht-54cm-x-25-4-100mm-sleeve-tandem-162491
3. I will differ to you on up-right riding prefs. I prefer the higher dutch-bike height over the English /Oxford low handlebar placement. Though that said, if i experiment with risers, i may indeed find just one of the double risers an acceptable compromise. However, i think i would find any of the vintage bars directly inserted into the brommie stem too low because it's more an S type riding height than an h type riding height.
I wouldn't want to be leaning onto vintage bars in an s type riding position as that puts too much body weight onto the bars which may be the reason you experienced a loose clamp issue. Also it defeats the point of having swept back grips which compliment upright riding.

cheers
s

 

[12boy]

Since stout headwinds are an issue here, an upright seating posture is too much work for me. The problem I found with the VO Porteur bar wasn't slippage but the bars were too narrow and seemed to increase twitchiness, especially going downhill fast, to scary levels. I have an Aber Halo but have never found a use for it. I have 4 bikes set up with ones' hands behind and below the place the stem holds the bar. For me, anyway, the rearward hand placement actually helps with an erect position as there is less leaning forward to grasp the bar. The Milano is currently on a Xootr Swift, a 20 inch folder not mentioned much on this forum, but the 45 degree angle of the sweepback is the most comfortable of my bars. Good luck with your efforts to find what works best for you.

 

[snazpizaz]

@12boy - oh cheers i was presuming you were riding a brommie and now i think you're saying none of the 4 bikes you use are in fact a brommie:
https://www.brompton.com/bikes/2020...qN2o7o1ElGXTZ2hu5X-G_NSgXpe4GbUBoC5NwQAvD_BwE
The fold on the brommie is very precise and there are 3 riding positions:
https://www.bikefolded.com/brompton-s-m-p-h-type-handlebar-differences/
I'm still inclined to think the Porteur is too small to handle steering on a brommie where the wheels are only 16"

I'm riding in London / South East UK region so headwinds aren't an issue here.
s

 

[berlinonaut]

@b-naut
1. your mentions:
"If you want to create a mod like that yourself: I think in the picture archives of the bromptontalk mailing list that just moved over to groups.io is a picture story of someone who did it himself "
"way less frightening than the seatpost solution but unfortunately not cheap either" - in 'neutral' summary - presuming it meant a cut-down seatpost solution.

Where did I mention a cut down seat post? You seem to be interpreting rather than reading...

2. I've had some feedback questioning if the Andros is that reliable, with reference to it's composite metals and a lack of user history, where as you seem a fan.

Again I'd prefer you would stick to what I wrote rather than to interpret and claim things I never said. I'm not "a fan" of the Andros, it is just the commonly available riser with the highest rise, the double clamping gives it an extra layer of safety in comparison to a single clamp and it seems to work flawlessly on the Tern bikes where it comes from. Still the design is possibly not intended to be opened and closed with every fold, several times a day. I own a V1 Andros and while it is ugly and heavy it has been working well until now. I do not think this makes me a fan and neither a hater of the Andros - I just look onto it from a technical perspective. But with that same perspective I would never ever come to the idea to stick two risers onto each other (at least not since I've grown older than 15 ), so possibly we do not share the same perspective...

3. On more vs less bolts / clamps: I disagree in that i tend to think the less clamps/ bolts along the length of a stem, that need constant checking and tightening the better for reducing experience of failure but i agree QR at the clamp needs to be robust.

Which is possibly another highlight on that different perspective. I consider a technical system in a critical position with a second layer of defense to be better and safer as it is to a degree tolerant to failure. For the same reason that airplanes have built in redundancy on their critical systems. I also do not think a QR needs or should need constant checking and re-tightening - in that case something is wrong with the QR or it's usage.

 

[snazpizaz]

Cheers
@b-onaut
1. So what was 'frightening' about the seatpost solution then ? Always the poss of not understanding what someone writes.
3. We'll have to agree to disagree on the bolts/risers and your stated riser-use age-bias which i didn't understand but wont try and interpret

cheers
s

 

[12boy]

I do have a Brompton as part of my fleet and rode it for a while today. You can hopefully get a good peak at the Soma moustache bar.

 

[snazpizaz]

@12boy - hey that looks ! - how does that look folded i wonder as it looks like its bolted on rather than QR ?
I see you've got the soma in 'upside-down' position. I've seen it in both. I guess that gives a good low-ride position. As mentioned before - i'm opting for the riser to raise the bar to h type height.
Your set up reminds me a bit of this:
https://www.flickr.com/photos/90727905@N02/with/8414538812/

s

 

[12boy]

It folds up ok if the QR is released and the bar rotated up. Because my hands are behind the handle post clamp I am in the same position as I would be with the standard S bar in terms of leaning forward, and if I put my mitts just behind the brake I am in the same position as leaning forward on bar ends. If I used reverse brake levers I don't think rotating the bar would be needed, but then I wouldn't have the little quick release doodad (the technical term) on the old Dia Comp levers. I like them because when released they allow me to pull an inflated wheel without undoing the brake cable. It's always been a pet peeve for me that the Brompton sidewalls don't have a release like almost all modern sidepulls. I 'll try to send a folded photo later today.

 

[12boy]

Here are some photos...note the sticker on the frame on the non drive side

 

[12boy]

Sorry about the picture of the aged pooch in with those.

 

[snazpizaz]

@12boy

thanks - useful - oh btw - we like aging pooches

That set up is very much what i've been considering as a budget solution - though as stated with a Toulouse bar on an andros stem. The fold looks snug there, despite the 60mm drop on the Soma.
A couple of questions:
1. What size QR are you using on the brommie handlebar stem handlebar clamp in those photos ? I understand that the nut/bolt sizing on that part of the brommie is 6 which is quite rare and so there are mixed views about which sizing QR to use as a replacement for that bolt. Most say a 7 but others suggest miss-matching the sizing will eventually degrade the threadings. Can you feedback on your experience ?
2. When you added the soma to the s type did you have to replace the brake/gear cables which were already onboard or were they already long enough to accommodate the turning down of the handlebar when folded - which seems to me to require a little slack ?

cheers

s

 

[12boy]

I used a standard seat post type QR since it would tighten enough. One reason I went to a QR is I lost the original bolt which I remember as being an odd size. The QR bolt is smaller and does not affect the threads as it uses its own threads as opposed to the handle post threads. Would be nice if the stock unit had a removable face plate like threadless headsets do.