Recommend quick release bolt for Brompton handlebar

Page may contain affiliate links. Please see terms for details.

snazpizaz

Well-Known Member
Location
London UK
Hi
Newbie question here; sorry – most probably really obvious to others…..
Can anyone recommend a quick release bolt which will fit the standard Brompton folding bike stem handlebar - clamp bolt hole sizes ?Does anyone know what diameter those bolt hole sizes are ?
Recommends, links and pics welcome
Cheers
sp
 

Attachments

  • brompton handlebar bolt 1.jpg
    brompton handlebar bolt 1.jpg
    44.9 KB · Views: 99
  • brompton-shandle bar bolt 2.jpg
    brompton-shandle bar bolt 2.jpg
    63.4 KB · Views: 100

sheddy

Legendary Member
Location
Suffolk
Can we ask why ?
 

mitchibob

Über Member
Location
Treorchy, Wales
Can we ask why ?

It's definitely not a bolt I'd ever want quick release, but I could understand why, if one wants their handlebars pushed that little bit further forward and it gets in the way of the fold, so want to quickly adjust to make fold still work. But I still would not stick a quick release bolt there under any circumstances.
 

Tenkaykev

Guru
Location
Poole
The metal there is formed to take the handlebars and I'd be concerned that constant tightening / loosening might affect the integrity of the metal.
The manual says to tighten the bolt to 18Nm so perhaps you'd like to practice with a torque wrench to get a feel for how tight it needs to be.
 

12boy

Guru
Location
Casper WY USA
I have used one for many years, first because I lost the odd sized Brompton bolt (7mm)? And later, because I went with barends and even later with a moustache bar because it is so easy to loosen and rotate the bar to facilitate folding. I like the moustache bar BTW, because it allows for a handshake type grip in lieu of the palm down grip required with a flat bar, because the bar and brake levers clear the Brompton basket bag and because I can use old road bike levers which have a quick release section that allows for wheel removal/installation without taking off the pads or releasing the cable. Just like the seatpost QR, a QR can be tightened or released many times without damaging the clamped area. I use an old seat post clamp since the bolt part is the right length.
 
OP
OP
S

snazpizaz

Well-Known Member
Location
London UK
Hi thanks everyone - some useful pointers here. See images to aid my answers

Why ? -
1. well i want to go with flat handlebars - the 'velo porteur' take my fancy and fit - length wise - 480mm, 50mm shorter than the H type handlebar.
2. I have an H type Brommie so i need to make up the 155mm height of the H type handlebar. I plan to use :
3. the 100mm double riser attached to the brommie stem
4. and then the 390mm tern andros handles attached to the 10cm double riser
This will create a height of 490mm, which is 60mm shorter than the rise in the H type handlebar but that creates a slack so re-attaching brakes and gears wont be a problem.

I get the point about not repeating the undoing of the handlebar bolt - i can see why that might become problematic. Perhaps i dont need to. I can just attach the double riser at a fixed up-right position.

The Andros handles will enable me to loosen and turn downwards my flat / swept-back handlebars when folding the bike and do seem designed to be used repeatedly. Also the slack i mention above, should allow the break and gear cables to accommodate the handlebars in a turned-down position.

I'd like to move the brakes to the under-side of the handlebar grips too - hoping the shorter length of the porteur handlebars and shorter height of the double-riser / andros handle combo will allow that with cable lengths as supplied . (bike on order - due shortly)

Anyway within all of that i thought it might be cautious to install a qr bolt at the brompton stem clamp anyway.

Feel free to advise on the proposal. I've been thinking it through and i think it will work okay. As you may have noticed - i am an up-right bicycle fan ! -

If anyone can recommend a better way of doing this - please feel free to link to products. I've looked myself but can't find any other way of making up the height of the brommie stem using generic stem risers/extenders AND enable the handlebars to fold downwards. Happy to consider any hacks or mods.

thanks !
sp
 

Attachments

  • vph.jpg
    vph.jpg
    71.2 KB · Views: 34
  • dsr.jpg
    dsr.jpg
    5.5 KB · Views: 39
  • tern andros handles.jpg
    tern andros handles.jpg
    34.2 KB · Views: 41
Last edited:

Kell

Veteran
Define better...

A more robust way, depending on the age of your Brommie, might be to swap the top part of your stem.

Pre- the recent standardisation, an H type uses a shorter folding top part so that the bars don't drag on the ground.

Mine (2015) was built to the following dimensions:

xJT_5uL9KBqvPCn7WFunMcMK3fY&_nc_ht=scontent-lht6-1.jpg


So, if I understand this correctly, the S type stem, despite giving the lowest bar height, is actually the longest stem. it might do away with the need for the DSR.

But if it were me, I'd seriously look at getting a set of bars made for you that have the rise of the M bars, but with a swept-back portion. The fewer extra joins you need to create, the better I'd say.

It does seem to be needlessly complicating things.
 
Last edited:

Kell

Veteran
PS - you're not the only one to mess about with your bike.

I ordered an H type, but fitted low risers to it to get a bar height somewhere between an S and an M. Never even rode it with the standard bars.

This is what I did.

XJqyRzcZJj2oYka3MMRmxYmD5wc&_nc_ht=scontent-lht6-1.jpg


Folds like this:

8OYk3jrgYXFqPLMQhw2HmWSXtnY&_nc_ht=scontent-lht6-1.jpg
-PAXP-deijE.gif


But having just spotted that your bike is on order, the whole stem swap thing might well be a moot point as I know they changed everything to try and standardise all the stems.

Still think something like a set of P bars with the ends bent backwards would be pretty close to what you want though.
 

Kell

Veteran
 
Last edited:

12boy

Guru
Location
Casper WY USA
I actually had Velo Orange porter bars on my S type. The narrower bars felt much twitchier, and when going down hill quite unsafe. I later tried some Milano bars from VO, and while they felt fine the clamp area wasn't enough to prevent them slipping down when I hit a bump. Next I tried some Soma moustache bars and the stem clamp,even with a QR, works well. The stem clamp with these bars is centered fore and aft and I didn't have the downward leverage of the Milanos. I have found that bringing the grip point further behind the stem clamp has much the same effect as raising the grip height, so that a low grip behind the stem clap allows the same erect riding position as a higher one in front of the clamp. I also believe that using the double riser/ andros setup will reduce the rigidity of your handle bar post and increase handling problems. Have you considered the North Road bars found on older British bikes? They have a fairly generous rise, the 22.2 mm bar width will allow using the Brompton brakes and shifters without needing shims. As I said above, getting your hands behind the stem clamp will also have the same effect as raising the grips with the double riser/andros combo without affecting rigidity. Both North Road and moustache bars will work with road bike type brake levers, BTW, and my old DuraComp levers have a release that enables me to remove or install an inflated wheel without releasing the brake cable or removing a brake pad.
 
OP
OP
S

snazpizaz

Well-Known Member
Location
London UK
Hi thanks all for continuing your advice.

For the others -
1. I have looked at just adding bar ends to the h type handle bar - it is an option - but i can;t find any qr detachables - so that puts me in the same position - might as well fit a shapely handlebar anyway.
2. I had looked at fixing a straight bar with bull horns backwards but why do so when vintage handlebars are cheaply available as the real thing ? However some bullhorns have built in ability to change angles but annoyingly their grip length is generally pretty small and don't make good swept back grips. If anyone can point me somewhere which contradicts this - please do so.
3. How easy is it to get handlebars made and who does this service ? I would want foldable/hinged/revolving swept-back grips in that case.
4. The bike is on order - but the difference between the H & S stem is faily minimal - I still would have to cover a extended stem issue with both. I've gone for the H because it's less hassly to adapt down to an s or m than an s is to adapt to an M or H.


For 12boy:
0. I've decided on flat non-rising handlebars which come in at a length close to the H type length of 530mm as these keep folding neat and compact and just require a turn downwards when folding.
Any handle bars with a slight raise built in , when it comes to folding they will stick out by the rise depth as well as any greater length when folded. So i rejected all the Velo / retro handlebars with a rise over 40mm and a length over about 545mm. That eliminated alot of good handlebars from the likes of Soma Nitto and Velo in particular.
1. I note yr feedback - that riding a wider handlebar with a slight raise felt more stable than the shorter length handlebar. Also that attaching it directly to the stem as is and not subjecting it to a further rise was workable for you too. I will play with that idea. Thankyou.
2. What did you mean by "The stem clamp with these bars is centered fore and aft and I didn't have the downward leverage of the Milanos." re 'centred fore and aft' and also 'downward leverage' means ? -
I note the clamp area diameter for the brommie is 25.4" and this is the case for most vintage handlebars from above suppliers. One or two of the vintage models are 25.4" from grip to grip but most others come similar to brommie handlebars with 22.2mm bars and grips - i want to avoid using shims if possible.
3. I eliminated north road (there are a number of makes) and milano because of the width and also the rise of the bars. I had a preference for the soma oxford in this catagory but they come in close:
https://www.velovitality.co.uk/products/alloy-north-road-style-handlebars
https://www.sjscycles.co.uk/handlebars/nitto-b302aa-north-handlebars-254mm-clamp-silver-490mm/
https://www.sjscycles.co.uk/handlebars/soma-oxford-handlebars-254mm-clamp-silver-540mm/

thanks again everyone - keep it coming !

sp
 

Kell

Veteran
The Brompton bars are 25.4 at the clamp, but get thinner to the ends.

I didn’t know the diameter, only that it’s smaller. But, as 12boy says, the North Road bars follow that format.

So, even though you’ve discounted them, the first set of bars you posted would be correct, and the only ones you’ve linked to that would allow you to fit the brakes and shifters from your new bike.
 
Last edited:
OP
OP
S

snazpizaz

Well-Known Member
Location
London UK
All of the handlebars in the above links have a clamp zone of 25.4" which would fit on a brommie. The brommie grip area diam drops to 22.2" as do all those in the link, except the last which isn't specified but looks to have a diam drop too. Most of the vintage handlebars are brommie friendly in terms of diams.
 

Kell

Veteran
Apologies, you're absolutely right.

I was convinced I 'd read the description for it to say 25.4 and constant diameter.

Don't know why I thought that.

As you were.
 
Top Bottom