http://bikeforums.net/attachment.php...hmentid=381727
like this one on my Curve duomatic

If the extenders aren't good for the quick release system, from a physics point of view, anything other than a straight bar would also be bad. I'm tempted to swap the handlebar to something like this:

Pake Ukiah Handlebars

Seems like it wouldn't be that different, but it could put a larger rotational torque on the clamp at the top of the handlebar post.

DCS

I've been thinking the same thing as you. Although at the moment I'm quite happy with the stock-bar rotated so that the ends droop downwards, with Ergon GP4 grips. I've also cut off 2 inches from both ends :-)

Would be good if others could give their thoughts re: torque issues.

Would be ****ull bar equhers could give their thoughts re: torque issues.[/QUOTE]
I used chopped down drops on my brummie with the dahon extender. Dahon do not recommend this, but I only had difficulties getting the bars to clamp up tight which I solved by swopping to an anodized bar and tightening up the qr so I could just physically close it. It works really well. My set up might be a tad stressful on a dahon STEM?

You may find you get more flex at the stem. Sorry would post photos but
Pc playing up at the moment . I have put bull bar equivalents and racing levers /brakes on down tube n's, mezzo and Brompton and always been very pleased with the results not had any stress fractures or cracks on any of the bike in 5 years plus of these mods

I have fitted bullbar

Personally I would not take the risk of any failure in the handling system,even though I like the flexibility of an adjustable handling system.
supposing a seat post failure during riding may not cause harm——you can still stay on the bike with your feet on the pedal. but what would happen if a handle post cracked during riding ?since nothing else could be used as a backup,it might be a tragedy.

It's a trade off. Improved handling and braking all the time I find in this postion, against a very unlikely but dangerous failure rate increase in theroy.

Folding bikes are a compromise.

I may have found my solution, just picked up a lightly used 2003/4? Helios SL for $350 on CL. It has an adjustable height handlebar, with the handlebar welded to the top movable post. Going to pick up an andros stem and cut the handlebars down to a t-post, then add a new straight bar. the SL is an awesome bike, but the handlebars are still uncomfortably close in the standing position for my 5'11" long-torso'd frame. As an added bonus, the andros stem will allow the handlebars to swivel up when folded and make a closer fold than stock with the fixed handlebar. Just have to decide whether black or silver would look best :)

http://bikeforums.net/attachment.php...hmentid=383310

dcs

So I got home and measured the handlebar on the Helios in the previous post - turns out it's too small for the andros stem... The handlebar tubes are approx. 21.5mm, and the stem (inner part of adjustable height stem) is approx. 24.5mm. I measured with a crescent wrench and ruler, so it's close but not exact. Now the question is how do I get an adjustable stem on this bike to move the handlebars forward? I'm thinking of buying something like this (mentioned earlier in the thread): Promax 1 1/8' Ahead Adjustable Stem with QR - £19.99 and then just getting an 8-10" piece of aluminum or light steel tube that's 25mm to connect it to the bike and replace the welded t handlebar piece altogether. Suggestions anyone?

dcs

Shim the difference out .. look for some 1 /16th thick shims.. the difference between 22.2 and 25.4 is 3,2 mm

Standard tube diameters for lots of bike stuff is Fractions of An Inch like 7/8 & 1" .. for most non Road Drop Bars

Would the shims be sturdy enough for an andros extender? After some searching, it seems that something like this: Universal Cycles -- Tranz-X QR Adjustable Quill Stem might be able to just install as-is (keeping the bottom wedge loose or removing it). Shimming is a good idea if I decide to cut the existing handlebars and go the andros route. Thanks!

dcs

The dahon androes stem needs a 25.4 (1 inch) clamp area. Standard bars are this or oversized 31
2 (memory going)

It needs a clamping area that width of 90 mm. Thats the problem. Most bars tapper and don't have a clamping area this wide. I shopped around to get mine.

+1，mine is Helios SL too.
My HSL with adjustable stem. got this second hand stem at a low price from a domestic online shop.
http://bikeforums.net/attachment.php...hmentid=383521http://bikeforums.net/attachment.php...hmentid=383522http://bikeforums.net/attachment.php...hmentid=383523http://bikeforums.net/attachment.php...hmentid=383524

That looks like a great solution, thanks for sharing! What type/style of stem are you using? It looks like it has an allen bolt on top to tighen it down like a conventional threaded fork style stem. If that's the case, do you actually tighten it down, or just rely on the quick release to hold it in place?

dcs

that depends on the mechanic .. the shim is a sleeve, to make the diameter bigger .


My Bike Friday bar, is 3 pieces sleeved over each other, in layers, in the center ..
1 piece tube in the core , 7/8" tube, width is in halves ,... and a split tube 1"OD clamped in the stem.

that compresses the split for packing Bars ..

Ah, that makes sense. Thanks! Looks like I have a couple options to consider.

dcs

mine is for threadless system.
http://img01.taobaocdn.com/imgextra/...!355091451.jpg
6mm allen bolt on top and 5mm beside , tightened it to a 28.6mm(1 1/8") tube with a star nut inside.
http://g.search2.alicdn.com/img/bao/...pg_170x170.jpghttp://img04.taobaocdn.com/imgextra/...!652791679.jpg
then they could be insert to the conventional dahon folding handle post lower,and locked by the QR.
http://www.pushys.com.au/media/impor...0V20560047.jpg

there are adjustable stems for threaded fork system, but the lower part is 22.2mm. too slim and too short for the dahon handle post to hold it.
http://img02.taobaocdn.com/imgextra/...!345022599.jpg

Some people in these forums have added a qr lever instead of the allen key to adjustable ahead stems. You want the threadless type and they could safely be shimmed up to over sized bars if thats the stem you get.
Sections of the Mezzo upgrade thread might be worth a read About this .
Have you got an andreos stem extender as they are a hens teeth item.

Wow, thanks for all the pics and info! My stem is approx 24.5mm (maybe 25mm, not sure what proper way to measure it is), and I was thinking that a 25.4mm quill stem might fit right down in there. I may order a cheap one to try it, and just put it on my old diamonback mtb if it doesn't or can't be made to fit.

I don't have one, but I really like the idea. Some of the adjustable ones look ok, but none seem to have the range that the andreos does, and it also looks like it would facilitate a better fold as well. The adjustable ahead stem is a good idea, too, I'll poke around for mods on those. Thanks for the tip!

dcs

Thanks again for the suggestions and info everyone! I found a solution that I'm going to try out for a while. Got a Tranzx quick release adjustable quill stem (st-71). Since I have the older style folding stem that takes a 25.4mm shaft, it's the same size as the diameter of the quill. I didn't need to be able to raise it up higher than it already goes when adjusted upwards, plus I got this one on ebay for about $14 shipped. Picked up an aluminum mtb bar from a shop for $5 used, and put it all together. It flexes just a little if I get on it, but overall I love the forward postion - changes the bike totally! It also folds the other way (see pic) for a very casual cruising position as well. The bike folds better than before, too (see pics). Now the axles actually touch frame when folding (impossible to fold tighter). I also added a cruiser style seat I had with shocks because I'm a wuss and like my man parts. I'll gladly haul the extra couple lbs of metal and fluff around for the comfort.

So for a total cost of about $390, I believe I have a bike I'll enjoy for a while :). It's certainly a treat to ride!


dcs

Before:
http://bikeforums.net/attachment.php...hmentid=386136



After:

http://bikeforums.net/attachment.php...hmentid=386127http://bikeforums.net/attachment.php...hmentid=386128http://bikeforums.net/attachment.php...hmentid=386129http://bikeforums.net/attachment.php...hmentid=386130http://bikeforums.net/attachment.php...hmentid=386131