What are your thoughts on this handlebar extension?
 

I bought this handlebar extension to gain another 2.5” or so of reach on my new folding bike. Does anyone have any experience with an extension like this, or thoughts on how it may or may not impact the handling of the bike? Any perceived issues? Obviously have not installed it yet - trying to decide whether or not to keep it. I could definitely use the extra reach though. Thanks in advance!
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it is pretty commonly used
if it makes the reach longer, I'm pretty sure it will make the bike less twitchy
I'd feel like it'd make the bicycle a PITA to fold, just that one extra step needed
maybe put some grip paste too

Thanks for the thoughts, and glad to hear it’s common. I wasn’t thinking about using any grip paste, since to fold I would just release the handlebar clamp and rotate the extension straight up, at which point the bike should just fold as usual.

Was also wondering if the extra pressure (if any) on the tall steerer assembly would be of any issue/concern. This is my first folding bike, so I don’t have experience with anything quite like this.

You've already bought it so go ahead and try it out. Another option would have been a riser bar tilted forwards. Let us know how get along.

Thanks, I saw riser bar options and those would work. Wanted to try this first as no need to remove brakes/shifters, and everything should fold normally too. We’ll see how it goes.

...as for how it will affect steering, once installed with the extender the grips will be farther than before from the steering axis, creating a larger circle (at the grips). This means that for a given turn of the steering axis, you'll need a greater angular displacement at the grips, but this will require less force. The principle here is the same as why a door knob is placed at the edge of the door, far from the hinge or turning axis. Conversely, the present set up without the extender requires less angular displacement, but greater force. Pick your poison. I myself prefer the quick, agile steering of the latter.

My concern with that is durability and safety. Seems fragile.

Why the extra reach? Guessing you're tall?
My only concern is the length of the extension, it's quite a bit of a change.
On the bright side, you can decrease the extension if necessary by installing at a greater or lesser than 0 degree rise.

Folding. Probably shouldn't interfere with folding. I installed a fixed stem of about 30-40mm on a Dahon and it didn't interfere at all.
Your mileage may vary.

Also, the handling shouldn't change in a negative way. Stem length does not significantly change the handling or stability of your ride.

I have that exact one.

remove the bolts before installation and reinstall with a dab of threadlock; one worked loose.

It’s not a hassle to fold. You will quickly get a feel for the amount of torque you need on the main bolt.

It‘s definitely the one to get, for my Tern at least, as the extra length of the extension means you can easily access the quick release on the handlebar post.

I highly recommend it.

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the four bolts ringed in red are the ones that would benefit from a dab of Loctite Blue.

Fitting this extension transforms the handling from ‘unpleasant, twitchy, almost dangerous’ to ‘acceptable, still a bit cramped but almost like a normal hybrid’

I call these devices double-clamps. Some are lightweight and will just hold accessories like lights and are very dubious for transmitting full handlebar loads when climbing. Some are beefier looking. Tern makes one that comes standard on their bike, lever quick release, beefy, heavy, expensive. I'll be trying a bolted one on my bike to both raise the bars (flat and aeros), and allow a quick disassembly for travel tight-pack, as my riser/handlepost does not have a clamshell opening handlebar clamp.

I found out these are available in a long length, 10mm more than the LitePro one I had. I need that extra reach on my Zizzo Liberte, so I just installed one. We'll see how it goes!

You asked if it affects the fold; it doesn’t.

raise it upright first, then fold as normal.

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How long are they center-to-center?

Ones that can withstand actual handlebar loads, I'm only seeing at 45mm C2C. Longer ones look flimsy, just designed to hold a short bar for accessories, not take handlebar loads.

I have a few questions, on my bar there is bulge and they taper. Is this a problem. The clamp is 31.8 but tapers. Is this a potential prombem?
Is it problem if force is place on it in its highest position? Is there much flex?
Is Ron Damon's door knob analogy valid for this case. I guess what he is saying is it creates more torsional flex. He can correcty me if I missed the point of his post.

These extension jigs come in 25.4mm and 31.8mm clamp diameter to suit the diameter of the handlebar center bulge. The latter are sometimes labeled as OS (for Over-sized). Choose accordingly.

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My earlier analogy to a door knob is a general principle that applies to any rotating structure. The farther from the axis of rotation the point at which force is applied, the smaller the force required for a given angular displacement. Conversely, the closer the force to the axis of rotation, the stronger the force required (but the smaller the angular displacement). This same principle applies to cogsets. The big, innermost cog feels the easiest, lightest because it is farthest out from the wheel axis. Same principle applies with these extender jigs. They extend the distance from the steering axis (the Pythagorean Theorem will tell you how much. The new increased distance from the steering axis is the hypotenuse. The two sides are the extender length and the original distance to the steering axis), meaning that it will take a lesser force to turn the steering axis, but with a longer "throw" or turn for a given angle. Note that none of this is opinion or perceptions, but rather fundamental Newtonian mechanics or physics.

Whether and how an extender makes steering more or less "twitchy" remains subjective so long as the term remains undefined and personal. Does it mean a propensity for lighter but longer throws? Or does it mean a propensity for heavier but shorter throws? What exactly is it meant by "twitchiness"?

I myself prefer the shorter, harder throws of a shorter moment-arm, but I appreciate the fact that if you need additional reach, you need the additional reach.

I would have to get 31.8 but it appears that it tapering some and I was concerned that taper might create stresses. If there is enough give to conform to the tapering, then no problem.

I had trouble understanding what your saying. The force is a torque force which applied at the same distance from the steering axis. Changing the point of the force does not matter. The moment stays the same. The only change being made is the length of the axis has changed. The distance that handgrip moves will be slightly larger to the small addtional length in stearing axis. So negligable. Pythagoris need not apply, not hiring. So explain what I am missing?

You are correct, the tapers are a problem, you cannot clamp there. This is an issue with me wanting to mount some Profile aero bars that have a wider clamp base, so my double-clamps would be on the tapers, no good. And I can't find bars with a wider center section, or narrow with step and not taper. So I'm going to need to mount those past the tapers where it is 22.2mm diameter, way wide but possible, but not a standard size for the double-clamps, so I'm gonna need shims to use at 25.4mm diameter clamp. The good part is, a wider mount base means less torsion into each double clamp when climbing standing and pulling on the bars alternating.

The other possibility is using a constant-section handlebar (like a Ti bar I have with a center shim), that will eliminate the tapers and I can put the double clamps just outboard of the aero bars.

No. The grips -- the place where your hands apply a torque or turning force -- are farther from the steering axis with an extender than without an extender. That's the point of the extender in the first place, to extend the reach or where the grips lie. There would be no point to an extender than didn't actually extend the reach or position of the grips. Consequently, the moment-arm is longer with an extender, and therefore the force required is smaller. Just like the pushing a door at the edge farther from the hinge requires less force to rotate it than pushing in the middle closer to the hinge. Just like a smaller cog feels heavier or more difficult to pedal than a big innermost cog. Just like turning a nut feels easier with a long wrench than with a shorter wrench. The moment-arms are different in all cases.

Moment- or lever-arms
 

Moment-arm: no extender
Handlebar: 58cm
O: steering axis
x: grip position

|x-------------O-------------x|

Moment-arm = distance x-O = 58/2 =29cm
.
.
Moment-arm: with extender

|x------------- o -------------x|
​​ ................ O ...............

x-o length: 29cm
o-O length: 8cm
Moment-arm= x-O length = √(29² + 8²) = 30.1cm

Basic formulaFor a given torque, a longer moment-arm requires less force.

Moment-arm with extender is longer, therefore the force required for any unit change in direction/angle is smaller. Is this a trivial, insignificant difference? Perhaps. Which should then make your skeptical about claims that it changes steering feel dramatically.

No, he is not changing handlebars to wider ones. He is just adding the extender. The torque stays the same. Where the torque is applied to the axis does not matter.

No one said that he is changing the handlebar to a wider one. All throughout, including the example above, the assumption is of constant handlebar width. You are obviously still not understanding how the moment-arm is increasing. The installation of the extender is effectively increasing the moment arm. And I have shown you exactly by how much, from 29cm to 30.1cm for a 580cm wide handlebar and an 8-cm extender.

You mean where the Force is applied. We apply a Force which results in a Torque. The resulting Torque is the product of the Force and the Moment-arm. If you apply the Force at the end of the handlebar at the grips, the Moment-arm is greater than if you apply the same Force closer to the steering axis. Again, look at the formula. Torque = Force x Moment-arm

The moment arm here is constant and is the distance from the handlebar grips to the center of the bars, assuming the bars are centered. That does not change. End of story. Pythag has nothing to with this. The force is about the axis.

By basic trigonometry, by the simple formula for Euclidean distance (a special case of the Minkowski distance, btw), I have shown you how the moment-arm is extended or lengthened by the extender. The extender has pushed the grips farther out from the steering axis relative to no extender installed. That was, after all, what the extender was meant to do, extend the reach, push the grips out forward. The distance between the grips and the steering axis is longer with the extender than without. Therefore, the moment-arm -- the distance between the grips and the steering axis -- is longer, extended. You obviously do not grasp basic trig or mechanics.