Curved folding stem question
 

Does anyone know if a curved stem noticeably increases the bikes "reach"?
I'm currently using a straight version with 2 QR's (for height and bar adjust) set at 37cm. I don't really fiddle with adjustments and rather get a simple, non-adjustable. Thinking a curved one will tame the steering as well. Any inputs will be appreciated

I did this on my Zizzo Liberte to try to get a little more reach. You can see it here: https://bikingtoplay.blogspot.com/20...-tall-guy.html

I didn't measure how much the curved stem gave me. I'm guessing it's in the 40-50mm range. About the same as the extension links, which I also applied.

The only concern I have--and it might be a big one for many people--is that the curved stem riser + links made the package too big to fit inside the fold (like the original Zizzo parts did). They fold to the outside, which makes the whole package significantly wider.

.....that's a very good point and likely a deal breaker for me. This helps a lot and thanks for including pics.

Its possible to obtain the same reach increase with a stem extender added to your stem with the advantage that it can be moved to obtain the same folded size as without it.


https://cimg0.ibsrv.net/gimg/bikefor...477058111.jpeg
On a Bike Friday, Bike Friday has several types of stem with extended reach, not only the curved one and the adjustable curved one can be turned 180 degree to reduce the folded size:

https://cimg2.ibsrv.net/gimg/bikefor...db4a1f88ff.jpg

Jipe Thank you.

...or a rise handlebar tilted forwards.

https://cimg6.ibsrv.net/gimg/bikefor...b414a8dd08.jpg

Ron Damon thank you. That's a good hack. I think a have an old azonic riser bar stashed someplace. Anyways, I slid the saddle back a few and rode the bike for a bit. The set-up felt better.

No worries, mite. I am full of ideas. Just ask the channel members, and they'll tell you. 😂

​​​​​And don't forget, the riser bar is tilted forward and installed upside down.

Ron Damon word up, bro. I do my wrenching as well. Guna try to keep the project simple so I'll keep the current geometry for now.

While we're on the subject... I am seeking double-clamps/stem-extender/riser that is in the range of perhaps 75mm center to center. Looked all over amazon, can't find what I need; Stout looking ones are shorter, and long enough ones look thin and flimsy; It needs to be stout enough to handle full handlebar climbing torque, not just provide a place to mount accessories. It needs to be two parts, to space apart. Application:

Raising only a clip-on aero bar from a flat bar, for comfort while taking pressure off hands. Current clip-on has forearm pads too close together, but at least bars come from top half of the handlebar clamps, so could just raise, right? Profile makes 70mm spacer/riser but says incompatible with Century bars, even though they look a perfect fit, then I realize why: They are skinny laterally, so raised up 70mm plus the side wings for the pads and under arm pressure, it may put too much moment on the riser bolts (unless the wings were a one-piece span).

I have a different set of profile clip-ons, Airstryke 2000, with flip-down wings with pads that are far enough apart, but the bars attach to the bottom half of the handlebar clamp, so if I use 75mm risers, those raise just the pads and the bars will need to be tilted up at a bad angle. Plus same incompatibility issue as above.

So the plan is Airstryke 2000, double clamps on flat bar just outside of width of aero bar clamps (which are right up against both sides of the handlepost stem now and can't go wider as one piece bar), facing up, holding a short bar that the Airstryke clamps to between the double-clamps, raising the entire aero bar, but not my flat bars.

Further complication: Due to where the flat bar tapers, and I can't clamp on that, I may need the double-clamps to be 22mm diameter as the flat bar is further out, not 25.4mm as it is at center. I might need to use round shims to bridge that difference.

Stout, like this or similar, only longer bar center to center:
https://cimg0.ibsrv.net/gimg/bikefor...0f105a7efc.jpg
NOT like this, I think these will twist in torsion, though I may be forced to try if I can't find like above. At least they would only transmit torque from the clip on aero bars, not my flat bar:

https://cimg8.ibsrv.net/gimg/bikefor...5a2a766dda.jpg

This is 90mm, great, looks light, but currently unavailable on amazon. Notice it has parts between the two clamps to clamp around a steer tube, thus is a complete stem. But I can't use those parts, my handlepost is topped with a welded clamp ring:

https://cimg0.ibsrv.net/gimg/bikefor...fdfddb413f.jpg
... and same thing with accessory mounts added via screw holes:
https://cimg6.ibsrv.net/gimg/bikefor...bf7dbcde06.jpg


Tern makes the following Andros stem, stout, FORGED, may be long enough, but expensive and heavy, though easily adjustable for folding:

https://cimg1.ibsrv.net/gimg/bikefor...aa2d2e3591.jpg

I use these on my Zizzo at 68mm, they seem stout enough (still some flex in the system, but nothing atypical for a folder).

This thing shouldn't be part of the conversation as it's not meant to hold anything more than a device or a light. I should know for I bought one and it arrived today. Definitely not meant for a handlebar.
​​​​​​

The Tern system (second generation) works pretty well. It has the advantage to be easily foldable to avoid any folded width increase.

Its the stem, which is very rigid, that is heavy. Tern has the same stem in several height.

That Tern system looks pretty slick. I'm thinking about trying it to regain the compact fold on my Liberte.

Duragrouch See if the "Syntace VRO stem" is applicable to your needs. They're adjustable and some extends to 135mm. I'm too new here to add links/images but there's a few on on ebay

That's not bad! Didn't look long enough when I last looked but that ad has the dimensions. EDIT: Ah, the longer ones are in alternate views in the ad. THANKS! EDIT: Well, these close on each side of the handlebar stem, would completely overlap the clamping area of the clip-on aero bars. So they would need to go outboard, but then just wide enough to clear the aero bars, and they are in the tapered area of the handlebar. Wider and they interfere with left trigger shifter which can't go any further outboard due to the brake levers (the original Microshift combined shifter/levers, the shifter broke, replaced with bombproof Shimano Alivio). So I'd need to replace handlebar with either, one that tapers further outboard, or one that tapers or steps down more inboard, and then use shims to clamp around the 22.2 dia instead of 25.4. Nothing's ever simple.

https://cimg9.ibsrv.net/gimg/bikefor...7c3f4f4ddb.jpg


Oh I agree, that was my point. I just wanted to say that for efficiency, lest someone suggest that as being long enough.

Only the double-clamp and not the T-stem, weighs 0.328kg or 0.7 lbs; That's on the heavy side, though understandeable as it is stout (and OEM stout as they have greater liability so I think go more robust), plus the additional weight of the levers. The Physis 3D handlepost, based on length from 250 mm to 350 mm, ranges from 1.5 to 1.7 lbs itself.

I've seen Syntace 60 mm clamps before, but not available here and I think they were $60. I now see 47 mm ones available, as just the clamps, not long enough. They are showing longer ones, with clamps as part of a typical aheadset style stem with a T for the clamps, and that is designed to clamp around a "plain" cylindrical vertical handlepost. My early Dahon post has the handlebar clamp (and C style, not clamshell) welded integral to the handlepost, and below that is tapered to wide at the base, so I can't clamp the VRO to it, unless I get a new plain handlepost, but I'm having a hard time finding one as long/tall as my old steel Dahon post.

Just the Tern Andros double clamps show at $60 on Tern USA but out of stock. There's a bike shop in Singapore that seems to stock them, says $75 marked down from $100, but I don't know if that is US dollars or other:
https://www.mybikeshop.com.sg/shop/b...n-andros-stem/

Duragrouch Yes, I can't find a "plain" cylindrical vertical post either. Tho, the diameter of my folding stem just below the bar clamp measures 28.5mm which will pretty much fit any normal mtb stem (28.6) with a bit of shimming or sanding. So, if the measurements are right, a somewhat extreme method would be to cut the top bar clamp off, install a star-spangled nut into the post and use any mtb stem. But with this method, the post height will be about 3-4cm shorter than before accounting for the loss of the bar clamp..

I'd contemplated same strategy, orginally thinking of mounting a suspension stem. But besides shortening the stem, mine is tapered the entire length, not tons, but enough that perhaps a clamped stem there will be tight at the bottom but air gap at top. I may have same issue with double clamps on my current handlebar, based on long gradual tapers between center diameter and at the grips.

Duragrouch Yes the folding stem is tapered but very gradually. Here are my measurements with a digital caliper. 28.53 just below the clamp and 28.58 about 4cm down.


https://cimg2.ibsrv.net/gimg/bikefor...e3da94f15d.jpg


It s a hair less than 28.6 but also most stems will have a clamp gap when tightened. Here are shots of my trail bike stems with the gaps indicated. So you can further tighten the bolts down to compensate. Or you can always use aluminum tape to increase the diameter.



https://cimg9.ibsrv.net/gimg/bikefor...abf77cb0d1.jpg
https://cimg7.ibsrv.net/gimg/bikefor...4f6de3c52c.jpg


I would do it if I have a spare folding stem to test and as long as your not pulling up wheelies or doing stunts on your bike, I think it's a fairly safe mod to do.

I don't have a caliper to measure mine. It's nearly double diameter near the base.

Gap: No, I don't mean at the clamping slot, and there, you should always have some gap, if not and the slot "bottoms out", you have questionable clamping force around the handlepost. By gap, I mean where the headset clamps around the handlepost or steer tube, both on bottom and top; If, due to taper, it's tight at the bottom but visible gap on top, then you are actually clamping around a shallow ring of the post, not secure and can work its way loose by slipping upward, and might actually leave a dent in the post.

YOUR post diameter difference is very small, that is not tapered, because you have an adjustable handlepost, so must stay constant size there. You should be able to clamp there fine, provided the tube wall thickness is sufficient to allow it. Mine is an old fixed height handlepost, with a lot of taper.

Duragrouch well, good luck on your search and hope you get it sorted out. As for for my original inquiry here, I ended up ordering a 35mm curved stem for my bike project. Fingers crossed