Curved folding stem question
#1
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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'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
#2
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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.
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.
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#4
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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.

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:


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:

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

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:

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:

... and same thing with accessory mounts added via screw holes:

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

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:

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:

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:

... and same thing with accessory mounts added via screw holes:

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

Last edited by Duragrouch; 11-11-24 at 01:38 AM.
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#13
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Its the stem, which is very rigid, that is heavy. Tern has the same stem in several height.
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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
Last edited by Gutless; 11-10-24 at 07:14 PM.
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I use these on my Zizzo at 68mm, they seem stout enough (still some flex in the system, but nothing atypical for a folder).

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
Last edited by Duragrouch; 11-11-24 at 12:39 AM.
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https://www.mybikeshop.com.sg/shop/b...n-andros-stem/
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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..
#19
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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..
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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.

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.


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.

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.


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.
Last edited by Gutless; 11-16-24 at 11:59 AM.
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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.

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.


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.

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.


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.
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.
Last edited by Duragrouch; 11-16-24 at 06:14 PM.
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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





